Physical Sciences

Liangzhu, Venice of the Stone Age, Collapsed Due To Climate Change

sb admin — Thu, 02 Dec 2021 08:41:56 +0000

Liangzhu, Venice of the Stone Age, Collapsed Due To Climate Change

In the Yangtze Delta, about 160 kilometres southwest of Shanghai, the archeological ruins of Liangzhu City are located. There, a highly advanced culture blossomed about 5,300 years ago, thanks to the engineering of large hydraulic structures.

The walled city had a complex system of navigable canals, dams and water reservoirs. This system made it possible to cultivate very large agricultural areas throughout the year. In the history of human civilization, it is one of the first examples of highly developed communities based on a water infrastructure.

And they did it all without metal.

Long undiscovered, the archaeological site is now considered a well-preserved record of Chinese civilisation dating back more than 5000 years and was declared a UNESCO World Heritage Site in 2019. However, the advanced civilization of this city came to an abrupt end.

"A thin layer of clay was found on the preserved ruins, which points to a possible connection between the demise of the advanced civilization and floods of the Yangtze River or floods from the East China Sea. No evidence could be found for human causes such as warlike conflicts," explains Christoph Spötl of the University of Innsbruck.

The dripstones of Shennong Cave (pictured) and Jiulong Cave provide an accurate glimpse into the time of the Liangzhu culture's collapse about 4300 years ago. Credit: Haiwei Zhang

Dripstones store the answer

Caves and their deposits, such as dripstones, are among the most important climate archives that exist. They allow the reconstruction of climatic conditions above the caves up to several 100,000 years into the past. Since it is still not clear what caused the sudden collapse of the Liangzhu culture, the research team searched for suitable archives in order to investigate a possible climatic cause of this collapse.

Geologist Haiwei Zhang from Xi'an Jiaotong University in Xi'an took samples of stalagmites from the two caves Shennong and Jiulong, which are located southwest of the excavation site.

Data from the stalagmites show that between 4345 and 4324 years ago there was a period of extremely high precipitation. Evidence for this was provided by the isotope records of carbon, which were measured at the University of Innsbruck. The precise dating was done by uranium-thorium analyses at Xi'an Jiaotong University, whose measurement accuracy is ± 30 years.

The massive monsoon rains probably led to such severe flooding of the Yangtze and its branches that even the sophisticated dams and canals could no longer withstand these masses of water, destroying Liangzhu City and forcing people to flee. The very humid climatic conditions continued intermittently for another 300 years, as the geologists show from the cave data.

Citation: Haiwei Zhang, Hai Cheng, Ashish Sinha, Christoph Spötl, Yanjun Cai et al. Collapse of the Liangzhu and other Neolithic cultures in the lower Yangtze region in response to climate change. Sci. Adv., 2021 DOI: 10.1126/sciadv.abi9275

sb admin Thu, 12/02/2021 - 03:41

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Physical Sciences

Greenland Could Lose Ice Faster Than Any Century Since The Last Ice Age Ended

sb admin — Wed, 30 Sep 2020 18:38:02 +0000

Greenland Could Lose Ice Faster Than Any Century Since The Last Ice Age Ended

A new estimate using sheet modeling finds that Greenland's rate of ice loss this century could outpace that of any century over the past 12,000 years, when the last Ice Age ended.

Scientists used reconstructions of ancient climate to drive the model, and validated the model against real-world measurements of the ice sheet's contemporary and ancient size.

The study brought together climate modelers, ice core scientists, remote sensing experts and paleoclimate researchers. The team used an ice sheet model to simulate changes to the southwestern sector of the Greenland Ice Sheet, starting from the beginning of the Holocene epoch 12,000 years ago and extending forward 80 years to 2100. Data came from ice cores to create maps of temperatures and precipitation in the study region that were used to drive the ice sheet model simulations up to the year 1850 while other published climate data were used to drive the simulations after that date.

Infographic describing the study's findings. Image: Bob Wilder / University at Buffalo

Scientists tested the model's accuracy by comparing results of the model's simulations to historical measurements. The modeled results matched up well with data tied to actual measurements of the ice sheet made by satellites and aerial surveys in recent decades, and with field work identifying the ice sheet's ancient boundaries.

"We built an extremely detailed geologic history of how the margin of the southwestern Greenland Ice Sheet moved through time by measuring beryllium-10 in boulders that sit on moraines," says co-author Nicolás Young, PhD, associate research professor at LDEO. "Moraines are large piles of debris that you can find on the landscape that mark the former edge of an ice sheet or glacier. A beryllium-10 measurement tells you how long that boulder and moraine have been sitting there, and therefore tells you when the ice sheet was at that exact spot and deposited that boulder. Amazingly, the model reproduced the geologic reconstruction really well. This gave us confidence that the ice sheet model was performing well and giving us meaningful results. You can model anything you want and your model will always spit out an answer, but we need some way to determine if the model is doing a good job."

Though the project focused on southwestern Greenland, research shows that changes in the rates of ice loss there tend to correspond tightly with changes across the entire ice sheet.

sb admin Wed, 09/30/2020 - 14:38

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Physical Sciences

What is an electron?

Amira Val Baker — Thu, 25 Jul 2019 16:51:58 +0000

What is an electron?

As surprising as it may sound, no one really knows what an electron is, and it is this fundamental question that has been the driving force for much of modern physics and eventually led to the development of quantum field theory.

To answer the question “What is an electron?”, you would think the first step would be to observe it. However, that is easier said than done. Electrons are simply too small for us to observe - the smallest thing we can observe is an atom and even that is not observed with a traditional microscope.

So, we can’t observe an electron, however we can observe its behavior, more specifically its energy. Currently this is done with Penning traps – a special device developed in the 1970’s with the purpose of trapping particles for extensive periods of time so that accurate measurements could be made.

What is important to note is that when we make such a measurement of the energy, we are in fact making a measurement of a single ion i.e. an electron surrounding a central nucleus – not a single electron.

In fact, it was this type of energy measurement that led to the discovery of the electron by J. J. Thompson in 1879. This discovery subsequently ended the idea that the atom was the smallest particle, with Thompson instead suggesting that an atom is composed of electrons surrounded by a soup of positive charge - the plum pudding model.

However, this was later found to be incorrect when Ernest Rutherford carried out his famous gold leaf experiments along with Geiger and Marsden, and concluded that the mass of an atom was concentrated at its center and thus proposed a model with a positive central nucleus surrounded by negatively charged electrons.

This model was further developed with the help of Niels Bohr, but instead of the electrons being randomly distributed he proposed that they existed in orbitals – orbiting the central positive nucleus analogous to planets orbiting a central nucleus/star.

Now with any model we should be able to explain what we are observing. A spectral analysis of hydrogen reveals a set of discrete emission lines which the Bohr model explains as the transition of electrons between orbitals. However, the Bohr model is only able to explain the emission spectra for hydrogen or other single electron atoms like ionized helium.

For multi-electron atoms the spectral analysis showed many more discrete emission lines that could not be explained by the Bohr model.

This is where the quantum model took over, where, instead of existing in precisely-defined orbits, all that is known about electrons is their probable distribution around the atom – generally referred to as an electron cloud. The electron cloud model was developed in 1926 by Erwin Schrödinger and Werner Heisenberg and can be explained in terms of a probability wave – specifically the Schrodinger wave equation – where the states or ‘orbitals’ that an electron can occupy in an atom is analogous to that of a standing wave.

In the quantum model these states, or orbitals depend on a set of quantum numbers for example the principle quantum number n, the angular momentum number l, the magnetic number m, and the spin number s. It is these different quantum numbers that define the position and momentum of an electron in terms of a probability cloud and describe the emission lines that were unaccounted for in the Bohr model.

This alternative view of electrons as probability clouds, rather than definite orbital states, successfully describes the behavior of matter. However, although achieving what the Bohr model couldn’t, it still doesn’t reveal the nature of the electron and where its mass comes from.

To get deeper still we need a model that more accurately describes the nature and structure of the electron which is just what is offered in the generalised holographic model introduced by Nassim Haramein.

This approach starts by defining the fundamental bit of energy as an oscillating spherical unit at the Planck scale – named the Planck Spherical Unit (PSU). Then, expanding on the work of physicists David Bohm, Jacob Bekenstein, Stephen Hawking, Gerard ’t Hooft and Leonard Susskind, it states that the energy – or information - of any spherical system is proportional to the number of PSUs within the spherical volume (volume entropy) and the number of PSUs available on the spherical surface horizon (surface entropy).

This holographic relationship between the exterior and the interior defines the mass expressed by the system at any given moment while the inverse defines the mass-energy density of the system – or as described by David Bohm, the unfolded and the enfolded, respectively.

The question is – can this approach be extended to the electron?

The first step in answering this question is to consider the spatial extent of the electron and the volume of information that it encloses. So if we start with the premise that an electron cloud can be considered as an ‘electron’ coherent field of information then instead of thinking about the electron as a separate system, the electron could be thought of as a cloud of potential energy spatially extending from the proton out to the radius where the volume encloses the electron cloud of a hydrogen Bohr atom. When we utilize this approach, we find an electron mass solution in terms of the holographic surface-to-volume ratio – the transfer potential - and a mass equivalent to the experimentally measured mass of the electron. So now we have a model that not only predicts the correct mass of the electron but as well offers a physical understanding of its structure down to the scale of the Planck length.

This new picture of the electron as a coherent collective behaviour of the Planck scale granular structure of spacetime offers us a deeper understanding of the nature of the electron. The details of this work were recently published in Physics Essays.

Amira Val Baker Thu, 07/25/2019 - 12:51

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Physical Sciences

Ask Ethan: Why Did Light Arrive 1.7 Seconds After Gravitational Waves In The Neutron Star Merger?

esiegel — Sat, 28 Oct 2017 05:18:09 +0000

Ask Ethan: Why Did Light Arrive 1.7 Seconds After Gravitational Waves In The Neutron Star Merger?

"Delay is the deadliest form of denial." -C. Northcote Parkinson

Every massless particle and wave travels at the speed of light when it moves through a vacuum. Over a distance of 130 million light years, the gamma rays and gravitational waves emitted by merging neutron stars arrived offset by a mere 1.7 seconds, an incredible result! Yet if the light was emitted at the same time as the merger, that 1.7 second delay shouldn’t be there, unless something funny is afoot.

In the final moments of merging, two neutron stars don't merely emit gravitational waves, but a catastrophic explosion that echoes across the electromagnetic spectrum. The arrival time difference between light and gravitational waves enables us to learn a lot about the Universe. Image credit: University of Warwick / Mark Garlick.

While your instinct might be to attribute an exotic cause to this, it’s important to take a look at “mundane” astrophysics first, such as the environment surrounding the neutron star merger, the mechanism that produces the gamma rays, and the thickness of the matter shell that the gamma rays need to travel through. After all, matter is transparent to gravitational waves, but it interacts with light all the time! 30 years ago, neutrinos arrived four hours before the light did in a supernova; could this 1.7 second difference be an ultra-sped-up version of the same effect?

The remnant of supernova 1987a, located in the Large Magellanic Cloud some 165,000 light years away. The fact that neutrinos arrived hours before the first light signal taught us more about the duration it takes light to propagate through the star's layers of a supernova than it did about the speed neutrinos travel at, which was indistinguishable from the speed of light. Image credit: Noel Carboni & the ESA/ESO/NASA Photoshop FITS Liberator.

There’s no doubt that the first gamma rays from this neutron star-neutron star merger arrived after the gravitational waves did. But why?

esiegel Sat, 10/28/2017 - 01:18

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Joel Mills,

Good question! Thank you!

I would imagine the neutrino signal ought to be comparable to that from a core collapse SN. What does the theory say? And how close would the event need to be (SN1987 was only a couple hundred thousand LY.) for detection.

General comment on this blog:

"In with Bang!... out with a whimper."

Really?! As your blog dies (I know you like the language), you go out quibbling about that 1.7 second difference!

Hi Ethan,
Please tell us something about Hoyel's steady state Universe.
How steady state Universe works?

Because Mooney, the 1.7 seconds is factual. Nothing you write is remotely close to factual.

#3
You quibble incessantly about something infinitely small when you say 0.999,,,,, isn't the same a 1. :-)

On reading about LIGO, a text said that when the black holes merged, 'they radiated 100 times more energy than all the stars in the universe combined'.
Is that right? Thats mind blowing.

Also I asked if making the chirp 'audible' was misleading - I assumed they must have shifted down. But it seems the frequency is in the audible range so maybe its not so bad. They compare the chirps from different objects to an orchestra, LIGO will only detect 'violins and violas' and new devices are underway to hear more. The Europeans are building and underground version of LIGO with arms twice as long.

And then there is the space detector with satellites a million miles apart. Fun time to be alive!!

Thanks Ethan for a great blog. Tell me where to go to follow your discourse.

Steve Blackband,

Where to go next: https://www.patreon.com/startswithabang

@dean #5: "Nothing you write is remotely close to factual."

Fact: The dimensions of physical objects and distances between them does not depend on how they are differently observed and measured, contrary to special relativity. The cosmos exists independently of all observation. the job of science is to accurately describe the world as it is, not to create an infinite variety of versions of it via differing observations, as relativity does.

Fact: There is no evidence for an actual entity/medium "spacetime" which is curved by mass and guides the motion of masses, contrary to general relativity. Yet GR claims the above as fact, beyond criticism.

Fact: There is no evidence for "Hawking radiation" by which black holes "evaporate," contrary to the beliefs of all Hawking followers (including Ethan.)

Fact: Nobody knows how old the universe is, because an eternally oscillating, "Bang/ Crunch" cosmos has not been ruled out, and no other model explains cosmic origin.
Related fact: "Everything manifesting out of nothing" is a blind stupid appeal to magic. It did not all pop out of a Cosmic Magic Hat.

Fact: personal attacks are not science.

@Steve Blackband #6
First, I didn't bring it up. Second, numbers are meaningless without referents in the world. Third, a very very very large and ever increasing PART of anything is still not the whole thing (represented by 1.)
Ability to think and reason clearly is at least as important as a high degree of expertise in crunching numbers.

Thanks John.

#3 sounds like a personal attack to me.

#10, "The cosmos exists independently of all observation."

How can you call that a fact when you cannot prove it i.e. cannot show it true unless you observe it?

#11. I was winding you up - hence the smiley face. I thought it was funny :-)

Not not being funny: then again, tell me what is between 0.999... and 1 if they are different.

I think we've done this to death. Signing off from this blog.
It has been fun and informative.
May the Bang be with you!!!!!

SB (even in your absence),
My #3 was not science. Ethan's focus on trivia ignores all major serious criticism, like my #10.

If you believe that things cease to exist when not being observed you are in serious need of a reality check. Even if the universe were only 13.7 billion years old, it existed for quite awhile before being observed. But that is too philosophical/ reasonable for you.
You seem to have ignored my answer in #11 to the stupid shit about a part being the same as the whole. Yes, it was done to death... until you resurrected it yet again.
Bye.

"Fact: personal attacks are not science."

That was not a personal attack - it was a statement of, well, fact. You continually object to things that experience and experiment support, and to theoretical conjectures of what might be, not because you have the ability to counter the physics with your own research or calculations, but because of your imagined offense to your third rate "philosophy of knowing" crap.

"Second, numbers are meaningless without referents in the world."
Mathematicians from the past and the present are laughing at you.

"Third, a very very very large and ever increasing PART of anything is still not the whole thing (represented by 1.)"

And they are boggled by your inability to understand even the simplest of concepts.

Ah well.
Its weird I think but I will actually miss MM.
#14, I dont have beliefs, thank you. You do, without evidence, You think that by just thinking you know what happened before.
I DONT.
we have theories that we test and until shown otherwise....
Crap. We don't even know what 96% of the universe is made of.
But by sitting around an jabber walking you can figure it all out.

Sorry dude. Not gonna happen.

You're a 0.999,,,, thats for sure.

Common now MM, THATS funny :-)

Have a good life my man. Its been a pleasure, for real.

numbers are meaningless without referents in the world

Those "referents" are usually called "observers." Anyway, does the Poincare group get to be sad here?

@SB #16: "#14, I dont have beliefs, thank you. You do, without evidence, You think that by just thinking you know what happened before.
I DONT."

Are you sure you don't BELIEVE that "philosophy is bullshit," to quote a famous physicist? You avoided any dialogue on philosophy of science that I presented. You have no clue that epistemology is the bedrock foundation of science. (Just more mystical philosophy to you.)

I do think (make that 'know') that the world must exist before it can be observed. Is that too philosophical?

I know that the whole observable universe didn't just pop into existence out of nothingness. That is religion, ("Let there be light!") not science. The oscillating universe is the only alternative to such nonsense.
The last word is yours if you want it.

Wow Mooney, you are clueless about everything

https://pbs.twimg.com/media/Cw-Fno-XAAA7dDf.jpg

Mondays shall hereinafter be known as "Snark Day."

General comment on this blog:

“In with Bang!… out with a whimper.”

Mirrors are your friends, MM.

You avoided any dialogue on philosophy of science that I presented.

Was this the list of random assertions preceded with the word "fact"?

Are you sure you don’t BELIEVE that “philosophy is bullshit,” to quote a famous physicist?

I'm pretty sure that Frankfurt was misusing what should be a term of art, if that helps. Get cracking.

Final comments on the value (or not) of philosophy.

Philosophy Is Bullshit:
https://webhome.phy.duke.edu/~rgb/Philosophy/axioms/axioms/node34.html

Many contemporary physicists continue to quote Hume. Nobody in physics has a patent on bashing philosophy, even though each physicist has one, lurking beneath their conscious awareness.
Instrumentalism is Ethan's avowed philosophy. Scientific realism is my choice for a science which intends to describe the world, not create multiple versions of it via our creative imaginations and theoretical speculations...
... here known as established facts according to Ethan's latest opinion.

I hope Ethan gets a job as a science fiction advisor. (I heard he applied to the Star Trek franchise.) He would allow a lot of "creative license" for impossible fiction like time travel ... and shrinking cosmic distances... and apply enough math to make it sound like science.

Ps: It's not just "snarky Monday." Every day here at SWAB is a snarky swarm of mainstream INITIATES all over any who dare to criticize.
I will not miss that.

"Final comments on the value (or not) of philosophy."

That should be on philosophy as you see it, not as it is. The way you see it, just like the way you view science and mathematics, is ass-backwards and ignorant.

You certainly will not be missed.

Many contemporary physicists continue to quote Hume.

This seems extraordinarily unlikely. Maybe you should have preceded the assertion with 'Fact:'. Have you even perused A Treatise of Human Nature? I haven't much encountered the principle of association of ideas in the literature, although an understanding here sure as hell could prevent you from incessantly making a fool of yourself.

P.S. MM: Do delta functions exist?

P.P.S. MM: Is the Levi-Civita symbol a tensor?

Narad,
The curtains have closed, the fat lady has sung, you need to go home now. Shoo.

The curtains have closed, the fat lady has sung, you need to go home now. Shoo.

Poor baby. Remember, there's always the "expanding Earth" approach to gravity if you get bored with the "electric universe."

Five Discoveries In Fundamental Physics That Came As Total Surprises

esiegel — Fri, 27 Oct 2017 05:00:54 +0000

Five Discoveries In Fundamental Physics That Came As Total Surprises

“On what can we now place our hopes of solving the many riddles which still exist as to the origin and composition of cosmic rays?” –Victor Francis Hess

It’s often said that advanced in physics aren’t met with “eureka!” but rather with “that’s funny,” but the truth is even stranger sometimes. Rather than the scientific method of: hypothesis, method, experiment, results, conclusion, revise, repeat, etc., many times throughout history, it’s been a series of surprise observations that have often led to our greatest leaps forward. When the speed of light was discovered not to differ when you moved with or against it, it was so revolutionary it was the only Nobel Prize ever awarded for a null result.

The Michelson interferometer (top) showed a negligible shift in light patterns (bottom, solid) as compared with what was expected if Galilean relativity were true (bottom, dotted). The speed of light was the same no matter which direction the interferometer was oriented, including with, perpendicular to, or against the Earth's motion through space. Image credit: A. Michelson / Michelson & Morley.

When the gold foil experiment resulted in high-energy recoils, it surprised Rutherford so thoroughly it was the most incredible thing to ever happen to him in his life. The leftover glow from the Big Bang was discovered quite by accident; the neutrino was a crazy hypothesis that many abandoned; and the discovery of the muon, perhaps the most unexpected particle of all, literally was met with a cry of, “who ordered that?” from Nobel Laureate I.I. Rabi.

The first muon ever detected, along with other cosmic ray particles, was determined to be the same charge as the electron, but hundreds of times heavier, due to its speed and radius of curvature. Image credit: Paul Kunze, in Z. Phys. 83 (1933).

These five discoveries changed the course of physics forever, but they came as total surprises to practically everyone. Sometimes, the answer is in the place you least expect.

esiegel Fri, 10/27/2017 - 01:00

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Physics

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Physical Sciences

”Light always moved at the same speed: c, the speed of light in vacuum.”

It’s probably because light has its own propulsion-mechanism. Think of a canoe vs. motorboat.

You can push the former and make it go faster; while the latter, that has its own propeller, keeps it’s own speed. The spinning blades neutralize the extra push.

—

”It was almost as incredible as if you fired a 15-inch shell at a piece of tissue paper and it came back and hit you.”

Again the same thing, it is probably because particles have their own propeller-mechanism. Think of two helicopter running into each other, where you have a small light toy helicopter that is blown back by a real on; and so it just returns to where it came from, or rotates backwards in the case of anti-matter.

—

”… radioactive decays have slightly less total energy in their products than in the initial reactants.”

An other thing that’s ‘normal’ if you look at particles as a propulsion-mechanism, and how you get a small jolt/bump when changing gears.

—

”It was later discovered that both composite particles and fundamental ones all have multiple generations of heavier relatives”

Having two helicopters smack heavily into each-other would have a similar effect, where some blades will shoot much faster away than the group-propulsion-mechanism.

—

”… they found uniform noise everywhere they looked on the sky.”

This one also wouldn’t be very surprising if we looked at particles as rotor-mechanisms. Think of curling waves in an ocean being tied together into propeller-mechanism-knot and all starting to take off, like a massive amount of helicopters taking to the skies. BBBbbrrrrrmmmm, BBBbbrrrmmmmm, BBBbbrrrmmmmm … and the noise you get. ?

"While the history we recount is filled with the success stories, real history is fraught with blind alleys, failed experiments, and outright mistakes."

Thomas Kuhn is smiling.

Merging Neutron Stars Deliver Deathblow To Dark Matter And Dark Energy Alternatives

esiegel — Wed, 25 Oct 2017 05:00:57 +0000

Merging Neutron Stars Deliver Deathblow To Dark Matter And Dark Energy Alternatives

"Dark matter is interesting. Basically, the Universe is heavier than it should be. There's whole swathes of stuff we can't account for." -Talulah Riley

One of the most puzzling facts about the Universe is that 95% of the energy in it, in the forms of dark matter and dark energy, are completely invisible, and have never been directly detected. Perhaps, the story goes, it’s our theory of gravity that’s to blame, rather than needing new components in the Universe. While dark matter and dark energy can explain a whole slew of observations, gravity modifications do a better job of explaining galactic rotation, but require altering Einstein’s theory of gravity.

The cosmic web is driven by dark matter, with the largest-scale structure set by the expansion rate and dark energy. The small structures along the filaments form by the collapse of normal, electromagnetically-interacting matter. Image credit: Ralf Kaehler, Oliver Hahn and Tom Abel (KIPAC).

But merging neutron stars provide a unique test: electromagnetic and gravitational waves both originate from an ultra-distant source over 100 million light years away. The first signals arrive separated by mere seconds, allowing us to constrain models where gravity and light are bent (and delayed) differently by the presence of masses. While theories like Bekenstein’s TeVeS and Moffat’s Scalar-Tensor-Vector predict differing delays by years, the observed arrival time difference was just 1.7s.

The various mass sources in between NGC 4993, where the neutron star-neutron star merger occurred, and the quantified delay that they cause in light/gravitational wave travel time. Image credit: Sibel Boran, Shantanu Desai, Emre Kahya, and Richard Woodard, 'GW170817 Falsifies Dark Matter Emulators'.

With these new observations, models that attempt to do away with dark matter and dark energy are largely busted, leaving only contrived, non-local modified gravity theories behind. It’s an incredible victory for Einstein and the dark Universe.

esiegel Wed, 10/25/2017 - 01:00

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There is evidence of the strongly interacting dark matter every time a double slit experiment is performed, as it is the dark matter that waves.

My guess is Dark Matter made of a particle (could it be graviton?).

And I don't think Dark Energy is a limitless form of energy keep getting created by spacetime itself, because it would go against conservation of energy (not to mention conservation of information). So it must be either a limited energy source (inside the Universe) that leftover from The Big Bang, or it maybe (negative) energy that our Universe is pulling in from outside (of the Universe).

All you have to do is...FIRST actually find some dark matter and energy, THEN things are going great.
.
Right now all you have is an empty black box place holder that you are ascribing phenomena to...which is not so great.

The way it works is... if we don't have a clue what causes something, we give it a name and pretend that now it's a known entity. Dress it up with math and, whaddaya know, it's "science."

The way it works is… if we don’t have a clue what causes something, we give it a name and pretend that now it’s a known entity. Dress it up with math and, whaddaya know, it’s “science.”

Do you "believe in" electrons?

@Michael Mooney #4,
Exactly. I was about to say the same thing. This entire debate about DM/DE/MOND revolves around the fact they don't know if it is: A force (as the MOND group wants)
or if it is : Energy
or if it is : Matter
That kind of doesn't leave anything else it could possibly be, short of magic, it's like checking all the boxes on a multiple choice test and claiming you got the right answer.
I call it 'Empty placeholder science'.
When I call what I cant see or measure or understand 'X', and claim that despite this lack of information, X is directly responsible for Y, even though I'm not remotely sure what X even is to begin with, and then put it into an equation, I STILL know nothing about what X is, and I STILL have nothing to connect it to Y, other than 'because I said so'.
.
Let's get rid of 'Dark (insert useless noun)', which is evasive and misleading terminology, and call it "I don't know", which is to the point and entirely honest terminology.

@CFT #3: That's an excellent description! We are kind of at the point now where Newton and Huygens were in studying light. They both had very good experimental data, but completely different mechanisms for the underlying physics behind that data.

For "dark matter," we have lots of detailed, quantitative observations, from many different sources, which all converge on a common description which both "explains" those observations and predicts new ones (the frustrating black box).

But we don't yet have any demonstrated theory for what physical mechanism (particles, fields, macroscopic objects) is hiding inside that black box. So we are stuck with (a) continuing to make and catalogue detailed observations to hopefully infer some explanation; and (b) make "guesses" (models) of different possible mechanisms, designing experiments or observations which can test those mechanisms. My own work is in one of the many different areas of (b), building an experiment to look for both high and low mass "WIMPs", one of the many different "guesses" for what causes our observations of dark matter. It will probably turn out to be wrong (like most hypotheses in real science), but if you don't test it, you can't even say whether its wrong or not.

For people who like their science as "given from on high," with clear, simply expressed descriptions that everyone agrees on, this is an unpleasant place to be. The kind of new type of observation (a) we have from GW170817/GRB170817a is very useful in pruning away whole sections of the forest of (b). In a perfect world, eventually enough such observations will prune down that forest to just a few remaining trees.

Narad #5,

I can't see air normally, but I can do all sorts of tests that can locate it, find out what it's made of, and directly interact with it by waving my hand.
I can't see electrons, but I sure can feel an electrical charge if I complete an electrical circuit, and I can measure electrical current as well, and predict certain properties about it.
We also don't fully understand electrons, despite knowing about their existence for quite some time. They may not actually do some of the things currently ascribed to them, as mainstream atomic models are sketchy.
.
I can't see dark matter/energy/ad nauseam. No known instrumentation can detect it. It has no measurable reactions to the entire EM spectrum that we are aware of, it 'theoretically' exists at all only because the math we use to describe gravitation can't explain certain observable discrepancies.
.
Where dark matter is concerned, presently all you have is 'belief'.

@CFT #6: I think that's a bit of an overstatement, at least for "dark matter" (I agree with you more on the "dark energy" front, but I still think you're over-generalizing).

Instead of "dark matter," would you be happier if we called it "unknown mass"? We have many, many independent observations, of entirely different classes of phenomena, all of which end up coming to a common conclusion: there is about five times more mass in any "large" (galaxy size or bigger) region of the Universe than we can detect electromagnetically.

You are quite right that (a) we have no freaking idea what this mass is, although we know definitively from one independent class of observations that it is NOT ordinary matter; and (b) different groups can "explain" different sets of observations in ways which don't invoke extra unknown mass.

The label "dark matter" is essentially there to identify the key feature of these observations: whatever it is, it doesn't interact electromagnetically, so we can't see it. But you're quite right about the annoying tendency, especially among theorists, to attach that "dark" prefix to things more or less unrelated to the actual observational puzzle.

I can’t see electrons, but I sure can feel an electrical charge if I complete an electrical circuit, and I can measure electrical current as well, and predict certain properties about it.

So, that's a "no"? Otherwise, you're both intellectually dishonest and historically igorant. The "electron" had precisely the same status as dark matter that you're currently whinging about as not being "science" – a theoretical entity.

When your uncertainty reaches 50%, you are just guessing.
When your uncertainty reaches 95%, you are bullshitting.
.

^ Oh, right:

We also don’t fully understand electrons

"We"? You're bad enough without invoking imaginary friends or plural minds, the latter of which are just as bad as everything else that's feeding your seemingly endless hemorrhoidal flare-up.

"… Einstein-Aether theories …"

Hey! ?

From the article: "When gravitational waves and photons (electromagnetic waves) pass through space, they're affected by the curvature and expansion of space in the exact same way."

I was under the impression that the curvature of space caused by the inspiral of these bodies WAS the gravitiational waves. May I ask where I've gone wrong in my understanding of the event?

@Narad #8,
Deflate thy ego just a tad, and stop conflating previous theoretical unknowns and claiming all of them are identical, they're not. 'Unknown' is not even the status of dark matter at this point, unknown can be corrected with an observation. Try 'UNDETECTABLE' instead, there is no way around that.
.
Contrary to your virtue signaling, I actually do know some science history.
With the discovery of the electron they didn't speculate for over 100 years about it, everything they were speculating about was also considered for experiment, tests were quickly designed to do so, and the results were measurable and repeatable, helping them to refine their models. They never went about (or even considered) proposing exotic 'undetectable' forms of matter or energy entirely outside of the realm of known nature to obscure or excuse the fact they couldn't locate or figure out how to account for discrepancies in their theories.
.
Long story short:
Electrons were never created to fudge predictive failures, they were discovered to be a constituent part of atoms through measureable, repeatable experimentation that was able to change pre-existing theory.
.
Dark Matter/Energy is just a black box excuse that was derived to account for a 95% predictive discrepancy in other theory the scientific community does not want changed.
It's a fudge factor.

@Elle. H.C. #11,
Many people are talking about DM/DE as being a form of theoretical backtracking into some variation of an Aether. Bee discusses this possibility on her site if you are interested.

@CFT #16,

Nah, I'm good.

It's just that there was a time, not so long ago, that aether-theories where taboo.

Sure the Michelson–Morley experiment dismissed the concept of an aether-wind, but it doesn't mean that all aether-models are completely flawed.

@Narad,
QM can't even fully describe a single electron, much less gravity, you angry twit. There's still a lot we don't know ('we' being 'humanity', which may or may not include your upset self).
.
Energy and matter are not and never have been probabilities, except as expressed in mathematical description only. Last I checked, nothing (including electrons) turns from an abstraction (such as a second hand calculation like a probability) into a thing and then back into an abstraction again. So no, I don't think we fully understand something we can't fully describe without resorting to outright reification.

Just read something interesting linked from Not Even Wrong. An essay written about what comes next for High Energy Physics, which directly or indirectly relates to the topic of Dark Matter and energy, depending on how you look at it.
.
Roughly paraphrased, science goes through three distinctive phases:
1.The phase of discovery.
2.The phase of consolidation.
3.The phase of Crisis.
These three steps play out over and over again through the history of all scientific endeavor. According to the author, Gian Francesco Giudice, in relation to the present state of the physics world, we are now in step 3.)The phase of crisis.
.
https://arxiv.org/abs/1710.07663

" outright reification."
Name it and claim it as a real entity. Apply math models for proof. Then call it science.
This is addressed to you, Ethan.

Ps: I really like the "Deathblow" reference in the title. Another victim on Ethan's Kill List of theories with which he disagrees!

@Narad #12,
As a disclaimer, I usually can't stand Sean Carroll's positions in physics, he has no qualms about eliding from math, to energy, to matter, and back again. He's also a fan of the 'many worlds' interpretation of QM, which isn't even testable science in my view. He does however point out something you may or may not be aware of, something that even caught him by surprise:
The physics community has no real agreement on the 'interpretation' of QM, it's all over the map. The most educated people in the subject do not agree what QM means, or which interpretation is closest to the truth:
.
https://www.youtube.com/watch?v=ZacggH9wB7Y
.
So things are not in as much in agreement as some would like to believe about a theory over 80 years old that is pivotal in all of physics. The general public is often confused about a lot of science not because they are stupid, but because the experts aren't so sure either.

@CFT #6:
"Let’s get rid of ‘Dark (insert useless noun)’, which is evasive and misleading terminology, and call it “I don’t know”, which is to the point and entirely honest terminology."

Good Idea. How can we do that? Those with impressive credentials certifying their indoctrination into contemporary mainstream astrophysics and cosmology... even without the evidence required by the scientific method... well... they rule the new metaphysical version of science. (Not much for short sentences with periods.)
You can't even find one criticism of relativity accepted by Wikipedia's article on "Criticism of the Theory of Relativity!"
That is dogma, not science.

@Frank #2: Talking about conservation of energy becomes more complicated when you're trying to take the entire universe into account.

@Michael Mooney #23,
I think the idea of relativity is mostly correct, but that doesn't mean Einstein got it completely right, or even completed it. He certainly didn't think so, and said as much on numerous occasions, a view he held until his death, so I am amused when people get indignant about relativity being challenged as if it was a blasphemy against some kind of holy writ in stone. If history is a guide, most likely it will be corrected or changed at some point.
.
One problem with relativity it is that there is no velocity transform, to go from v to v'. The tensor math is also mostly a smoke screen just to make the math look edgy. I suspect Einstein was convinced to do this by some of his colleagues in order to dress his ideas up by shrouding them in complexity...an idea that is very popular to this day.

@Naked Bunny with a Whip #24:
I had read those before but still I have simpler views of my own.

I understand that energy conserved locally not necessarily mean it must be conserved globally. My view is there is no good reason to think why it shouldn't be conserved globally unless someday we have a clear evidence against it.

Keep in mind countless discoveries and solutions to problems in physics were because of assuming energy must be always conserved. That assumption never let us down before so why doubt it now?

In reality, even the things we think we know, we really don't understand on some fundamental level. All we can do is invent theory, and math, and experiment to determine which theories aren't ruled out yet.

So no, we don't know in some fundamental godlike sense what an electron is. We know it carries charge, and has mass and spin, and obeys probabilistic QM equations. But from that point on its just fancy math all the way down. We may know how to manipulate that math in very creative ways, but we still will never fully understand why it works.

The tensor math is also mostly a smoke screen just to make the math look edgy.

Dear G-d, are you a Sad Sack.

@Narad #28,
I'm going to say this gently:
Something that is not needed to solve a problem is a waste of time and a unnecessary complexity, that's doing the reverse of what mathematics is supposed to do, winnow out the extraneous. A Minkowski metric is not needed to solve a general relativity problem, it's just being used to model a Euclidian space or flat spacetime anyway. If you really want to save yourself a lot of unneeded work, reverse all the gravity vectors in the problem. Consider it a working example of the equivalence principle, because that is what you are doing. Einstein did it this way himself, he even demonstrates it in 'Relativity' where he works out a problem this way using an elevator car in space. Doing it this way you remove the reason for doing all the tensor math entirely, it just isn't required in General Relativity, like I said before, it's a smokescreen. Try it both ways and decide for yourself.
.
I think I'm done with your snark Narad. It's time for you to move on and bother other people now.

CFT,

Once again, you've gotten your ideas on the math wrong. Tensor math, while it may not be familiar or easy for you personally, is actually introduced as a simplification, rather than a complication. The fundamental idea of relativity is that the laws of physics are the same for all observers. Now, laws of physics generally are best described with mathematical equations. In general, if you write a mathematical equation, you must go through and check that this equation will apply to all possible observers (in technical terms, you must prove that the equation is invariant under coordinate transformations of certain types). Using tensors is just a way to make this job easier. Tensors are DEFINED to be invariant under the required coordinate transformations.

Short version: expressing the laws of physics in tensor equations guarantees that they will be the same for all possible observers, thus saving the work of proving this. It may be possible to write these equation in non-tensorial form, but doing so does NOT simplify things, it complicates them.

#29 - "Something that is not needed to solve a problem is a waste of time and a unnecessary complexity, ..."

What's funny about this is your habit of using 10 times more words than necessary. Remain calm and carry on...

Sean T,
Instead of telling me this for the choir, try the math the way I describe. If Einstein could do it that way by way of demonstration in his own book, I'm hard pressed to figure out why you think it's a bad idea.
.
@Alan G., I was going to leave the one liners to you, but whatever dude. yeah. cool. Like, like, Fer Shure.

Once again, you’ve gotten your ideas on the math wrong. Tensor math, while it may not be familiar or easy for you personally, is actually introduced as a simplification

Nonono. It's a conspiracy to obscure the 19th (18th?) century Twoof of which CFT is the standard bearer. Who was the guy who thought returning to quaternions would allow one to extract energy from driving past a fire hydrant? He was better than CFT. Hell, Gene Ray and the Time Cube were better than CFT.

^ Here we go (tinw).

I think I’m done with your snark Narad.

How do you feel about unitary groups? Lorenz gauge? All a smokescreen to keep you from counting on your toes?

^ Almost forgot, but before I get down to real work:

CFT, which is more "real" in Maxwell's equations, E and B or A and φ? You may need to lick a 9 V battery before answering in a considered fashion.

"Dear G-d, are you a Sad Sack."

What a succinct, yet thorough, description of cft. Brilliant.

^^ I take it that nabla is some sort of blood libel.

CFT,

I have no doubt that any problem can be solved in multiple ways. For the purpose of physics, though, a manifestly covariant equation is by far the simplest, most elegant, most relevant way to go. That would be the tensor math. It is the simplest form of problem solving for the purpose of the study of physics.

With any other formulation of problems in physics, you MUST confirm that your solution applies in reference frames other than the one that is considered during the process of solution. Otherwise, it's not a valid general solution to the problem. It is only a solution that is applicable in a specific reference frame. With the tensor formalism, this step is not necessary since tensors are defined in such a way as to guarantee that the equation is valid in all reference frames.

CFT,

Maybe an analogy would make things more clear. Suppose you wanted to "prove" that the square of a number is equal to two times that number. Your method is analogous to saying, "let's consider the number zero. Zero squared equals zero, and two times zero is zero, so the formula holds. Maybe, zero's special. Let's try two. Two times two is four, and two squared is four. Aha! My formula works here too, so it must be generally applicable."

You have not proven anything in general, obviously. Any other value would obviously not hold in your formula. In like manner, if you solve a problem in physics without tensors, you have only proven a special case. With tensors, you can automatically prove general results. That's why tensors are used.

@CFT #25: "I think the idea of relativity is mostly correct..."

I beg to differ... well, not to beg, actually. No doubt the math of GR is an improvement over Newtonian physics for gravitational calculation. But when Einstein adopted Minkowski's model of spacetime curved by mass he made famous the reification of it as a malleable entity, not just a geometric model for the math. I still hope for evidence of an omnipresent field by which EVERYTHING is connected. That would dismiss the "problem" of "spooky action at a distance," for which "curved spacetime" was the intended remedy.
As for "special" relativity, surely you don't subscribe to the philosophy that physical objects and distances shrink, depending on the frame of reference from which they are observed. That is the most obvious difference between instrumentalism (a contemporary form of classical idealism) and scientific realism. There really is a physical world independent of differences among observers and their measurements. And "proper length" measured from at rest with the object is the valid description thereof. One traveling near c would need the Lorentz transform to correct for (possible) distortion when (if) planets and stars *appear* to be flattened. No, all frames of reference are not equally valid, and length does not vary with observational perspective.

Sean T, @30 wrote: " The fundamental idea of relativity is that the laws of physics are the same for all observers."

Rather, the laws of nature remain the same regardless of the observer. The job of physics is to accurately describe the laws of nature.

There really is a physical world independent of differences among observers and their measurements.

This is merely a demonstrably wrong statement of half-assed pseudophilosophy.

^ Before anyone starts, let me correct that to "clearly arguably wrong." This nonetheless requires a response that does not involve tantrums.

Narad,

What is it about the proposition "entities exist independently of the perceptions of an observer" that you believe is “clearly arguably wrong.”

Perhaps before taking on that question, would you flesh out what you mean by “clearly arguably wrong”?

What is it about the proposition “entities exist independently of the perceptions of an observer” that you believe is “clearly arguably wrong.”

If you had been following MM's screeds, you would realize that this is just another way of saying, e.g., that time dilation isn't "real." It's a remarkable exercise in the epistemological rarity of Bad McPozzm.

@Michael Mooney #40,
I said I think relativity is mostly correct, and the need for transforms. I don't agree with all of it, or with some of its interpretations. I don't believe in spatial/time distortions as being actual as some do, I believe those are the consequences of viewing things from far away with a limiting factor of c, you need transforms to correct for these distortions if you are going to get a clear picture of what is on going from very far away traveling at very fast speeds. I believe how something appears from far away at relativistic speeds is not how things are there, just how they appear when viewed from my perspective.
This to me is fundamentally no different than any other optical illusion or visual distortion, I studied art and perspective once upon a time and I know there are a lot of ways you can exploit how the eye and the senses work to present the appearance of something that isn't actual. I know that when I look in a funhouse mirror, I'm not actually distorting, my reflection is. When I drive by a fence in my car, I know the fence isn't actually blurring, that is how it appears to me, and I accept that to someone standing by the fence it might be me that appears blurred to them from their perspective. When I look at the night sky, I also don't think I'm actually looking back in time, I'm just looking at a light that left it's source a very long time ago, no time warping was needed to explain it, just realization that while light seems instant at relatively close range, giving us the impression we are in the same moment as what we see, the reality is there is a delay which becomes ever more apparent the farther away something is. If I see you on the other side of a canyon, and I notice through my binoculars you are shouting something, and then your lips stop moving, and then I hear you faint voice echoing, I know this does not mean there is a time distortion, it means the light I am seeing you by travels much faster than the speed of the sound you made when you shouted creating the illusion that your lips and voice were not in sync. Had I been standing next to you, I would not have noticed any such illusion, your lips and voice would have been in perfect synch.

@Narad,
Even if I did agreed with you on something, I'd still say you are unsuited to explain jack, as you lack self control and are arrogant. Make your point without personal insults, or you don't have one.

@Narad,
The Earth is not a flat disc, even if you think it is. If you do think the world is round, your thinking it round is not what informs its shape. Reality exists independently of you, what you know about it and how accurately the knowledge describes it is another matter. Descartes existed, therefore he was able to think about it, not the other way around.

Narad,

Is it, based upon your response above (currently #44), accurate/reasonable/fair to believe your opinion is that entities exist independently of the perceptions of an observer?

Is it, based upon your response above (currently #44), accurate/reasonable/fair to believe your opinion is that entities exist independently of the perceptions of an observer?

No, I reject ontology outright, but that's neither here nor there, as I accept methodological naturalism.

Even if I did agreed with you on something, I’d still say you are unsuited to explain jack, as you lack self control and are arrogant.

The irony, it burns. May I recall that you refused to address a perfectly coherent and detailed response by Michael Kelsey because you were suffering from a case of asshurt?

^ Ah, I have a reply to CFT in moderation, perhaps forever.* In the meantime, I might as well ask how his naive crude version of physics explains why fermions require a 720° rather than 360° rotation to get back to where they started.

* Maybe I'll redo it. Maybe not.

^^ Oh, right, Ethan for some reason only allows one link in a comment, rather than two.

Narad,

Interesting!

So, based upon your "No" response above (currently #50), is it accurate/reasonable/fair to believe your opinion is that entities do not exist independently of the perceptions of an observer?

And yes, I believe the rule is only one link per comment.

So, based upon your “No” response above (currently #50), is it accurate/reasonable/fair to believe your opinion is that entities do not exist independently of the perceptions of an observer?

Snazzm, yes. I sense that you might not be fully taking in the content of the comment you're referring to.

Narad,

More interesting!

Based upon your “Snazzm, yes” response above (currently #54), what happens to an entity when your perception of it ends while it remains perceived by another observer?

Ok, now the Snazzm, yes” response is #55! :)

@John #56: "... what happens to an entity when your perception of it ends while it remains perceived by another observer?"
Good question.
In fundamental idealism, every time you blink the world ceases to exist. But by the miracle of your personal observation, it comes back into existence when your lids are open to see it again.

Based upon your “Snazzm, yes” response above (currently #54), what happens to an entity when your perception of it ends while it remains perceived by another observer?

What other observer? You're conflating philosophy with physics, which I explicitly disavowed.

In fundamental idealism, every time you blink the world ceases to exist.

You don't understand rejection of ontology, do you, MM?

Nara,

"What other observer?" ... chuckling ... Ah! There is nothing except your mind right now - which is why this exchange isn't happening!

Feel free to explicitly disavow whatever you please, for doing so will change nothing.

Ah! There is nothing except your mind right now

No, you've confirmed that you don't understand what rejection of ontology means. "You are attached to names and forms," in the canonical literature. Whether you have a mind is your problem, and it has nothing whatever to do with physics.

^ Let me help: what's the reason for CPT invariance?

Nara,

As I commented above, feel free to reject or disavow whatever you want. Doing so changes nothing. Idea exchanges occur during argument, not during denial, rejection, or disavowal.

Remember, this exchange isn’t happening. :)

Remember, this exchange isn’t happening.

No, you've again demonstrated that you're a philosophical primitivist. Would you care to say anything about the subject matter? It would be unfortunate if John from Baltimore were yet another sockpuppet for Travis Schwochert from Endeavor, Wisconsin.

Nara,

How is that possible if this exchange ceases to exist when you are not looking at it? How can I be anything if I an not when you’re looking elsewhere?

Of course I am a sock puppet! I’m anything you imagine me to be .. or not!

I said I think relativity is mostly correct, and the need for transforms.

"Transforms" of what? It can't be the metric, which you reject out of hand.

Nara,

How is that possible if this exchange ceases to exist when you are not looking at it? How can I be anything if I an not when you’re looking elsewhere?

Joh,

As I've said, that's your problem. Care to say anything about physics?

Joh,

One postscript: where is mathematics? Is it in your head? No, wait... Is it in the Cosmic Mind? Where does it exist in the sense that you apparently can't express coherently?

Narad,
I had written you off as a moron/ heckler but this almost made me "laugh out loud." (I was mildly amused.)
" Care to say anything about physics?"

I just shared a summary ( in a reply to CFT) of my criticisms of relativity (both GR and SR.)

Care to say anything besides personal insults about those criticisms?... Scientifically speaking, of course. !! This is an Inside joke. You seem unaware aware that you are just here for an adolescent dog fight for dominance. You don't know the language of impersonal scientific dialogue.

This blog is nearly dead, so let's just finish with radical honesty (Not the popular kind... tough love for addicts... sold in books... when you do a search on it.) Say it as you see it. Get over your adolescent attitude and speak science (impersonal) as this blog closes.

I already did reply to your comment, Mr. Reading Comprehension.

Narad,

Math is wherever you want it to be, of course! And, when you’re not perceiving it, it doesn’t exist - or so you’ve suggested.

Snazzm!

Feel free to disavow that if you wish.

Math is wherever you want it to be, of course! And, when you’re not perceiving it, it doesn’t exist – or so you’ve suggested.

No, you can defend platonism or put your half-witted metaphysics back in your pants and play with it there.

Narad,

Remember, you’re the one who thinks that entities don’t exist independently of your perception of them.

Feel free to defend, or for that matter, disavow it. :)

Narad,

It’s what you perceive that counts, right?

Nothing else.

I just shared a summary ( in a reply to CFT) of my criticisms of relativity (both GR and SR.)

Wait, if it was the "transforms" one, you seem to have gotten some pseudonyms reversed.

^ Oh, no, it was "I still hope for evidence of an omnipresent field by which EVERYTHING is connected." Yup, more bad metaphysics. Have you three ever been seen in a room together?

Narad,

What’s your perception of that? Or not, of course. ?

Where's Hilbert space, John?

Narad,

By your criterion, wherever you perceive it to be, of course!

Reality exists independently of you, what you know about it and how accurately the knowledge describes it is another matter. Descartes existed, therefore he was able to think about it, not the other way around.

Endorsing Cartesian dualism – which is a form of supernaturalism – is nothing to be proud of, CFT.

... chuckling ... But solipsism of the present moment is?

Quoting CFT as this forum dies:
" Descartes existed, therefore he was able to think about it, not the other way around." Good one!

This cosmos existed, is existing and will exist totally independent of human or any other entitiy's observations, measurements, theories or ideologies (biases.)

Wannabe scientists, check your biases at the door. All others have a personal agenda. "god help us."

An unreasonable appeal to a metaphysical... beyond physics... omnipresent entity. There can be no proof of consciousness transcending the brain, let alone being the omnipresent field which is the universe in which we all live.

Personal testimony doesn't count in "science" today, because the liars (con artists) and delusional "witnesses" are still, I think, the vast majority.

That doesn't rule out legitimate accounts of unexplained phenomena. Science must be skeptical regarding "paranormal phenomena."

When (if) you experience a personal epiphany, don't try to explain it to "science." It doesn't have the "instruments" to detect or verify consciousness, let alone universal consciousness.

Thanks for the entertainment, Ethan. Seriously.

Narad, people who think math informs existence are already engaged in platonic mysticism, and that belief is held by a large percentage of mathematicians and physicists.

Strange that you have difficulty understanding that you had to exist prior to being able to insult people. If you believe causality to be metaphysical, then stop responding to what other people say and proving yourself wrong.

What is really strange is that SR is based on the false notion embodied in idealism... that reality depends on the testimony of various (theoretical) observers, i.e.,
The world does not exist independent of whatever observation of it, and it varies with the unique frame of reference.

Now it is dogma, not science, beyond criticism. (Check Wikipedia.)
Nearing THE END, but "It's not over 'til it's over."

@Michael Mooney #85,
I found a book that might interest you. I does cover quite a bit of the things we've discussed about the institution of education and how science is regarded among professionals.

The book is Disciplined Minds by Jeff Schmidt.
https://www.scribd.com/doc/102797697/Disciplined-Minds-Schmidt

@Michael Mooney #85,
This is a link to a site that considers alternatives to Einstein's explanation of gravitational lensing. I myself question the mainstream interpretation of gravitational lensing, I suspect it could easily be caused by refraction and defraction of light through the edges of solar atmospheres. On a hot day, if you look at the hood of a car, you can see a distortion caused by light passing through the heated air near the surface of the car. If this much distortion is possible from warm air, imagine how much a stellar body could warp light passing through its super heated atmosphere? Just a thought to consider.

https://www.youtube.com/watch?v=fePQdJNVF9g

CFT,
Thanks for the Disciplined Minds link and the video on refraction vs gravitational lensing. I'm quite sure that the mainstream indoctrinated majority here at SWAB will dismiss both without due consideration.
"Curved spacetime" is presently dogma beyond criticism. My favorite chapter title in the book is Chapter 4, Resisting Indoctrination. The irony is that the more thoroughly one is brainwashed the less one is aware of it... like those who actually accept that a" pancaked Earth" (as per SR) is an "equally valid" description of our beloved near-sphere home.

It has been good hanging with you, maybe the only one here with whom I consistently agree in opposition to the mainstream and their established dogmas-as-facts.
Thanks.

@Michael Mooney,
That sad truth is, the more one blindly accepts in the name of 'science', the more one believes in anything with a veneer of authority, and the less one questions for themselves what is going on in the world around them.
I do believe technocrats are the biggest threat to personal understanding and freedom the world presently faces.
Sadly, this is what Ethan advocates for.
"Technocracy:
a system of governance where decision-makers are selected on the basis of technological knowledge. Scientists, engineers, technologists, or experts in any field, would compose the governing body, instead of elected representatives."

@CFT #89:
How about Meritocracy, instead of Technocracy?

Endorsing Cartesian dualism – which is a form of supernaturalism – is nothing to be proud of, CFT.

… chuckling … But solipsism of the present moment is?

You really have no comprehension of philosophy whatever, do you? Monist materialism and monist idealism are at least mildly respectable. Dualism instantly collapses under its own weight.

I'm simply tossing the lot out the window, Chuckles. None of it is necessary.

Strange that you have difficulty understanding that you had to exist prior to being able to insult people.

Why would that be? Perhaps you're under the impression that you have to have some sort of noumenal existence in order to be insulted.

If you believe causality to be metaphysical, then stop responding to what other people say and proving yourself wrong.

"Metaphysical"? There's obviously no metaphysics without ontology – again, that's your bad habit. It's like clowns out of Volkswagen with you three.

That sad truth is, the more one blindly accepts in the name of ‘science’, the more one believes in anything with a veneer of authority, and the less one questions for themselves what is going on in the world around them.

Well, what do you surmise is "going on in the world" around you? Who put it there? How does it work? Where does it come from? When does it occur? Why is all this happening to you?

This is a link to a site that considers alternatives to Einstein’s explanation of gravitational lensing.

Dear G-d, the Velikovskian/Electric Universe cranks? You've truly outdone yourself, CFT.

On a hot day, if you look at the hood of a car, you can see a distortion caused by light passing through the heated air near the surface of the car. If this much distortion is possible from warm air, imagine how much a stellar body could warp light passing through its super heated atmosphere?

What? You think a "stellar body" can create an Einstein ring? This is doubly hilarious.

Narad,

"I’m simply tossing the lot out the window..."

... smiling ... Sure. The baby with the bathwater.

"... None of it is necessary."

Neither is your solipsism of the present moment, which is what your affirmation (at #55), "Snazzm, yes" of my question "... is it accurate/reasonable/fair to believe your opinion is that entities do not exist independently of the perceptions of an observer?" is.

Narad,

You see, when you renounce all except what your perception makes immediate, as you did at #55, you've renounced the basis upon which physics rests - that there is something other than what you perceive.

That's why I was surprised when you rejected at #50, the idea that entities exist independently of the perceptions of an observer?

Still, if you prefer to embrace the notion that entities do not exist independently of your perception, you're certainly entitled to that POV.

I suspect you'll find very few people who embrace Science to agree with you, but given your penchant for dismissing what you disagree with, I'm sure you'll be satisfied with your decision.

@ CFT #69:
" Scientists, engineers, technologists, or experts in any field, would compose the governing body, instead of elected representatives.”
You forgot mathematicians, all experts "out standing in their fields"... with their calculators.

Well, ... the "governing body" of physics (Elite academia... Granters of Phd's) does not allow criticism of relativity in any form, be it GR or SR.
That is my major complaint. "It depends on the observer" is not science. Neither is the invisible "Fabric of Spacetime." The greatest deception in science, still alive in the minds of Einstein's totally indoctrinated followers.
But which version will you believe? He changed his mind a lot, just like his (de-facto) successor, Hawking... as the most famous physicist!
I'll be gone from this pretense of unbiased science after tomorrow.

Narad,

While it may be true that what I think are my comments addressed to you (ref here the "Narad," introduction of each) are in fact merely part of some strange dream you perceive you are having, I'm willing to wager that most people who read this exchange of comments will also think that I am not you, nor you me. Perhaps you'll think they too are part of your dream, and you may be comfortable with that.

However, they and I will think you are mistaken, about our non-existence, and your belief expressed at #55 of the non-existence of that which you do not perceive.

Good luck, my friend. You will need it.

Narad,

" You think a “stellar body” can create an Einstein ring? This is doubly hilarious."

I would not have expected you to find reality "doubly hilarious", but you do have a special POV, and that perhaps aids your sense of humor.

"Hundreds of gravitational lenses are currently known. About half a dozen of them are partial Einstein rings with diameters up to an arcsecond, although as either the mass distribution of the lenses is not perfectly axially symmetrical, or the source, lens, and observer are not perfectly aligned, we have yet to see a perfect Einstein ring. Most rings have been discovered in the radio range. The degree of completeness needed for an image seen through a gravitational lens to qualify as an Einstein ring is yet to be defined."
https://en.wikipedia.org/wiki/Einstein_ring#Known_Einstein_rings

Narad,

Permit me to bring to your attention that an Einstein Ring is a special case of gravitational lensing, caused by the exact alignment of the source, lens, and observer. A black hole (BH) can serve as the lens.

You've left out the "stellar body" part, along with the analogy to a car hood, Peaches.

"Peaches"? LOL!

Narad,

"You’ve left out the “stellar body” part ..."
You are mistaken to think that was important. In the theory of general relativity, a black hole could exist of any mass, while QM places the lower limit at the Planck mass.

For stellar mss black holes, follow the link below to learn from Ethan.

https://medium.com/starts-with-a-bang/the-smallest-black-hole-in-the-un…

“You’ve left out the “stellar body” part …”
You are mistaken to think that was important. In the theory of general relativity, a black hole could exist of any mass, while QM places the lower limit at the Planck mass.

Perhaps you failed to read the comment I was responding to.

"I myself question the mainstream interpretation of gravitational lensing, I suspect it could easily be caused by refraction and defraction of light through the edges of solar atmospheres. On a hot day, if you look at the hood of a car, you can see a distortion caused by light passing through the heated air near the surface of the car. If this much distortion is possible from warm air, imagine how much a stellar body could warp light passing through its super heated atmosphere?"

My last word on relativity in a nutshell, repeated from #41:

Sean T, @30 wrote: ” The fundamental idea of relativity is that the laws of physics are the same for all observers.”
(The constantly repeated mantra of relativity.)
I replied:
Rather, the laws of nature remain the same regardless of the observer. The job of physics is to accurately describe the laws of nature.
THE END

Narad,

"Perhaps you failed to read the comment I was responding to."

That is, of course, irrelevant, as a stellar mass BH can effect the gravitational lensing which you find "doubly hilarious", but which you seemed unaware.

... chuckling ... You were responding to my comment #99 - until I pointed out your mistake. You had already responded at #94 to CFT about his post #87.

I note also that you have permitted to stand as stated, the comments in re solipsism of the present moment (ref here comment #55) which deny the basis upon which physics rests – that there is something other than what you perceive.

^ Thank goodness such "car hood" temperatures are not readily obtained in the laboratory.

Oh, wait.

I note also that you have permitted to stand ignored as stated moronic simpering, the comments in re solipsism of the present moment

FTFY.

Narad,

Yes, you have permitted to stand as stated, the comments in re solipsism of the present moment (ref here comment #55) which deny the basis upon which physics rests – that there is something other than what you perceive.

"FTFY"? LOL!

Narad,

We both know that the position you adopted at #55, that it accurate/reasonable/fair to believe your opinion is that entities do not exist independently of the perceptions of an observer, is untenable.

Why not admit you made a mistake and move on? Do you really want everyone who reads this thread to see you as claiming that entities do not exist independently of your perceptions?

Do you really want everyone who reads this thread to see you as claiming that entities do not exist independently of your perceptions?

You missed the part where I deny that I have a noumenal existence. Where in G-d's name did you get your education? It certainly didn't involve physics, philosophy, or world religions.

Narad,

"Where in G-d’s name did you get your education? It certainly didn’t involve physics, philosophy, or world religions."

Feel free to introduce religion into the exchange. I won't respond to it.

As for your "I deny that I have a noumenal existence", yes your comments are often about what you deny. Feel free to deny whatever you wish; your denial will change nothing.

The position you adopted at #55, that it accurate/reasonable/fair to believe your opinion is that entities do not exist independently of the perceptions of an observer, is anti-science. I've called you out on it, and your posts indicate that you'll just repeat your denials.

It's right there at #55 for everyone to read in response to the inquiry if your opinion is that entities do not exist independently of the perceptions of an observer?

"Snazzm, yes"

You can't make your comment go way - even if you deny it.

The position you adopted at #55, that it accurate/reasonable/fair to believe your opinion is that entities do not exist independently of the perceptions of an observer, is anti-science.

No, it's not. Apparently, you don't know the difference between ontology and science, hence my question where in G-d's name you might have purchased a university degree–shaped object.

“Snazzm, yes”

You can’t make your comment go way – even if you deny it.

Why would I want it to go away?

Narad,

"No, it’s not.[anti-science]"

Actually, yes it is.

"Science (from Latin scientia, meaning "knowledge") is a systematic enterprise that builds and organizes knowledge in the form of testable explanations and predictions about the universe."
https://en.wikipedia.org/wiki/Science

The position you adopted at #55, that it accurate/reasonable/fair to believe your opinion is that entities do not exist independently of your perceptions denies the existence of the universe independent of you.

You remain mistaken.

Narad,

"Why would I want it to go away? [#55]"

Because it affirms an anti-science POV (denial of the universe independent of you), which is at variance with how you have attempted to portray your position.

Nara,

Now, perhaps you embrace self-contradiction in how you present your intellectual position to others.

If that is so, please let me know, and I'll leave you to enjoy that unusual approach to discourse.

@#116 "Nara" s/b "Narad"

MM,

Certainly, we in the scientific community will listen to any reasonable and intelligent criticism of relativity. The problem is that you have given none. You have simply shown your misunderstanding of it, but have not actually given any valid criticism of it.

The laws of nature are the same for all observers, right? (quoting you). One of those laws is that an anisotropic force will lead to a spherical object (approximate, assuming the anisotropy is also approximate). This leads to our correct conclusion that the earth is spherical in our reference frame. However, the moving observer measures an ISOTROPIC force of gravity. The force of gravity is GREATER along the axis of motion than it is in the perpendicular direction. The laws of nature don't change for this observer, so given a greater force in one direction than in another, what shape should that observer see?

We don't directly observe this, but suppose we look up in the sky with a REALLY good telescope, one much better than any currently built by orders of magnitude. We observe a planet. We find a way to measure the diameter of this planet along the axis perpendicular to our line of sight and also along our line of sight. We see this planet has a significantly shorter axis along the line of sight than along the perpendicular direction. What should we conclude? This is a perfectly valid description in our reference frame; how could it not be? We made the measurements. Obviously, SR leads us to conclude that the most likely case is that we are moving rapidly either toward or away from that planet and what we observe is the predicted length contraction in the direction of motion. The residents of that planet would, if they understood relativity, accept this as a valid description in our reference frame. The MM's on that planet would argue that we are of course being ridiculous and assure the MM on this planet that his measurements are obviously incorrect, despite all the care he took in making them.

How do you settle the question. Who's right and why? I understand you are a scientific realist, but how do you distinguish between the possibility that the true reality is that this planet is spherical and only appears to be flattened for moving observers and the alternate possibility that the true reality is that the planet is actually flattened and it is only the stationary observer to whom it appears to be spherical? The basic content of relativity is that such a distinction cannot be SCIENTIFICALLY made. If you want to make such a distinction, then that falls outside the purview of science and entails non-empirical means for making it.

BTW MM, one of those laws of nature that you agree is the same for all observers is that light in a vacuum travels at the speed c. This is the case regardless of the motion of the source or the observer. Once you accept the notion that the laws of nature are the same for ALL observers, relativity follows deductively. It's actually just a mathematical system with the axiom that the speed of light is the same for all observers. Deducing length contraction, time dilation, etc. is pretty easy mathematics once this principle is in place.

Michael Mooney,

Sean T's point at #119 is well taken. If you accept the speed of massless particles through a vacuum is the constant c, it is difficult to avoid accepting Einstein's relativity.

Actually, yes it is.

“Science (from Latin scientia, meaning “knowledge”) is a systematic enterprise that builds and organizes knowledge in the form of testable explanations and predictions about the universe.”
https://en.wikipedia.org/wiki/Science

Ooh, argumentum ad Wikipedium. I am duly impressed, except for the fact that you apparently can't even read what you quoted. Where's the ontology in there? You do know what this word means, right?

Frankly, I don't know what you're so uptight about. The last time I saw this kind of a routine, it was from a postmodernist I happened to be dating (and who also fancied Borges, of all people). The bonus here was that in one argument during which she was particularly vexed, she hissed at me, "I bet you believe in science."

Out of comity, I refrained from observing that she had no problem "believing" in flush toilets.

Because it affirms an anti-science POV (denial of the universe independent of you), which is at variance with how you have attempted to portray your position.

"At variance" how?

Narad,

#121 - "Ooh, argumentum ad Wikipedium." ... chuckling ... Okay perhaps you'd prefer the OED: "The intellectual and practical activity encompassing the systematic study of the structure and behaviour of the physical and natural world through observation and experiment" https://en.oxforddictionaries.com/definition/us/science

Your comment #55 accepts "Snazzm, yes" that "entities do not exist independently of the perceptions of an observer" rejects the physical and natural world you do not perceive.

I'm sure you and your lady friend both believe there is a loo behind the closed door although neither of you can see (perceive) it without opening the door..

#122 - Perhaps you don't think denying the existence of tested entities when you are not perceiving them takes the edge off of your claimed methodological naturalism, but those who do think the universe exists independently of the observer might think otherwise.

e.g. entities x and y had to have been extant to test, and did exist to test, and remain extant for future tests.

Per your truth claim at #55, entities x and y did not exist prior to your perception (observation/test) or after.

Narda,

If existence is merely the universe of entities (physical or otherwise) in your mind at a moment (solipsism), why can you not control this exchange, or any exchange, or every exchange by your thoughts?

Solipsism is unfalsifiable in the sense in which Karl Popper used the word: it is impossible to determine whether it is true or false. So I think your truth claim at #55 falls well short of being persuasive and that the solipsist position makes genuine communication impossible.

… chuckling …

Yes, you seem to interject that frequently in lieu of saying something intelligent.

Okay perhaps you’d prefer the OED

It's just more descriptivism, and has nothing whatever to do with the point.

Your comment #55 accepts “Snazzm, yes” that “entities do not exist independently of the perceptions of an observer” rejects the physical and natural world you do not perceive.

Have you figured out what 'Snazzm' means yet?

#122 – Perhaps you don’t think denying the existence of tested entities when you are not perceiving them takes the edge off of your claimed methodological naturalism, but those who do think the universe exists independently of the observer might think otherwise.

"Takes the edge off"? This is word salad.

e.g. entities x and y had to have been extant to test, and did exist to test, and remain extant for future tests.

The deuce you say. Please explain how this works with entanglement.

Per your truth claim at #55, entities x and y did not exist prior to your perception (observation/test) or after.

What, pray tell, do you think a "truth claim" is? Even better, let's cut to the chase: Do you think the constancy of the personality is noumenally real, or purely phenomenological?

Narda,

If existence is merely the universe of entities (physical or otherwise) in your mind at a moment (solipsism), why can you not control this exchange, or any exchange, or every exchange by your thoughts?

Jonho, that's finally an intelligent question. It's because "The Secret" is not Madhyamaka.

Narad,

"It’s just more descriptivism"
"Have you figured out what ‘Snazzm’ means"
"This is word salad"
etc.

I doubted that you could go the distance with your solipsistic vision (although I was initially intrigued by your efforts), and as you have elected to not respond in both #125 nor #126 you have convinced me.

... chuckling ... And yes, you did amuse me.

as you have elected to not respond in both #125 nor #126

You've managed exactly one intelligent remark, and bailed on the response to that. If anyone should be glad this exchange is going to go bye-bye, he's in your mirror.

Narad,

"...he’s in your mirror."
Look and see! LOL!

I will grant you that your posts have demonstrated the solipsist position makes genuine communication impossible.

... smiling ... And you're very much welcome to it.

I will grant you that your posts have demonstrated the solipsist position makes genuine communication impossible.

You have yet to demonstrate that you have anything to communicate in the first place, much less the ability to do so. You proceed, like MM, simply by assertion – ironically, without referents (aside from W—dia and the zero-rent version of the OED, which itself you obviously don't understand). I'm not surprised that you've evaded the question of your alma mater.

Narad,

“ the zero-rent version “

As if a “for fee” version would have a better definition?

More amusement.

Ask Ethan: How sure are we that the Universe is 13.8 billion years old?

esiegel — Sat, 21 Oct 2017 05:00:18 +0000

Ask Ethan: How sure are we that the Universe is 13.8 billion years old?

“Normal science, the activity in which most scientists inevitably spend almost all their time, is predicated on the assumption that the scientific community knows what the world is like.” -Thomas S. Kuhn

For all of human history, the biggest questions have fascinated us. Where did the Universe come from? How old is it? And what is its ultimate fate? Once relegated to the realm of theologians, poets, and philosophers, science has brought us closer than ever to the answers. But scientific revolutions have occurred before, in many cases significantly changing the answers to these and other inquiries. How certain are we that this won’t happen again?

The Sun, the Earth, and the history of life on our world all have a consistent age today, but back in the late 1800s, the evidence for the age of the Earth suggested it was significantly older than the Sun. Image credit: NASA, ESA, and ISS Expedition 37.

When it comes to the question of the age of the Universe, presently estimated at 13.8 billion years, there are many uncertainties that could come into play. Dark energy could evolve over time, fundamental constants might not be constant, or today’s fundamental particles might be broken up into smaller components. Additionally, we could have flaws in the expansion rate or composition of our Universe, or even alter General Relativity.

The four possible fates of our Universe into the future; the last one appears to be the Universe we live in, dominated by dark energy. What's in the Universe, along with the laws of physics, determines not only how the Universe evolves, but how old it is. Image credit: E. Siegel / Beyond The Galaxy.

But it really looks like 13.8 billion years is safe, to within perhaps 2% at most. How can we be so confident?

esiegel Sat, 10/21/2017 - 01:00

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ask Ethan

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Physical Sciences

Is the Hubble constant really that uncertain?

All I get when I post at Forbes is "please reload and try again." So here is what I posted:
Most cosmologists refuse to consider the question, "What, if anything existed over 14 billion years ago?" If nothing, how did it all magically manifest out of nothing.
Consider the eternally, perpetually oscillating model, even though we can not presently measure the time span of such a two phase, "bang/ crunch" model... given that it's still expanding at an accelerating rate. No more magic of everything pulled out of a cosmic "magic hat!"

@Another Commenter #1: It's not that the Hubble "constant" has that large an uncertainty. Rather, it's that there are two entirely different measurements which come out that far apart, but each with much smaller uncertainties!

When we use the "cosmic distance ladder" (look it up) to relate redshift values to distances of galaxies, which is the method Hubble himself used, the various observational groups have converged on a value around 72+/-3 km/s/Mpc. Basically, this value is the _current_ Hubble parameter, measured using relatively nearby objects (z < 2 or 3).

On the other hand, you can use a combination of CMB and "baryon acoustic oscillation" (two-point correlation distances between galaxies) to extract the Hubble parameter. Those observations converge on a value of 67 +/- 0.5 (ish) km/s/Mpc. This value uses observations from much, much higher redshift (out to z ~ 6 for BAO, z ~ 1189 for CMB), but it is still supposed to reflect the expansion rate here and now (because that's what affects our observations).

Notice that both values are reported to be very precise -- that is, the statistical and systematic uncertainties evaluated for each method independently are quite well controlled.

The problem, as you can see, is that the two different values are not even close to mutually consistent! We currently don't know why. That's why it's an active area of research, and not a final, fixed value (like 'c').

"13-8-billion-years-old is spatially non-inclusive & chronologically inconsistent".since 5 billioni or so years was required to form this comparatively miniscule solar system that is far less than the 2-400 billions of Ma billionthCheck capstonepublishing@surewest.net

----
13-8-billion-years-old is spatially non-inclusive & chronologically inconsistent.
-----
Air Pollution results too from degradation of protective elements there; allowing deeper penetration of destabilizing lethal space rays.
-------

10/19/2017
With widely announced reports of casualties from world pollution being so exceedingly great; the worth of clean air, water and contaminant free soils and foods becomes further emphasized and the need underscored. This also infers that ground water, being tainted by chemically laden ashes from homes and towns that have burned to the ground; homes Containing plastics, household chemicals, electronics casings. industrial solvents etc. that yet need be better prevented from contaminating; and doing so by wise planning and construction and forestry management. Further actual value can be derived from societal pursuits that do not increase or require daily polluting commuting, breathing lingering wildfire smoke, and the equally dangerous fumes from detonated weaponry being used worldwide by peoples not realizing the after effects of lingering barbarism and refusal to rather nurture mutual regard also for the planet's life sustaining land foliage -plants, trees-and other wildlife, long preceding human presence on tthe planet.

Further value can be derived from not only abandoning the long adversely ramifying death dealing sado-masochistic world 'cults of mayhem, injury,decimation and death' but rather seeking and actually both pursuing and accepting whatever actually leads toward greater global safety and stabiity; and especially when such more optimal outcomes can and do present evidences of sure achievement and attainment, however unprecedented.

Among such novel occurrences are those widely seen successful demonstrations during the past three decades; of difficult to access wildfires being more quickly suppressed without chemicals and costly air flights, in over two countries and three states. The modes the advanced collaborative modes introduced, saved benefitting states and countries billions in firefighting, restoration & medical expenditures, yet were largely disparaged and likely deemed coincidental. This too underscores how humankind -even when shown better provenances to pursue, are prone to disregard and devalue the implications;, preferring the more risky costly familiar pursuits.

Further value can be derived from not only abandoning the long adversely ramifying death dealing sado-masochiswtic world 'cults of injury, decimation and death' but rather seeking and actually both pursuing and accepting whatever actually leads toward greater global safety and stabiity; and especially when such more optimal outco0mesw can present evidences of sure achievement and attainment, however unprecedented.

"13-8-billion-years-old is spatially non-inclusive & chronologically inconsistent" since even this far smaller stellar system required 5-6 billion years to be formed .Check capstonepublishing@surewest.net for the more detailed treatise/series.

References to this matter was made on cra8gslist months ago, and at wonderfulcounsels.net (an A.T&T. blog, but Bitcoins were being sought for enlisting staff Artists and filmmakers for the more graphic film and video portrayal and book publishing. Many sense the 13. billion year dating lags behind more recent astronomical discoveries, but need more factual elucidation.

Seeing One Example Of Merging Neutron Stars Raises Five Incredible Questions

esiegel — Fri, 20 Oct 2017 05:27:54 +0000

Seeing One Example Of Merging Neutron Stars Raises Five Incredible Questions

"O. Hahn and F. Strassmann have discovered a new type of nuclear reaction, the splitting into two smaller nuclei of the nuclei of uranium and thorium under neutron bombardment. Thus they demonstrated the production of nuclei of barium, lanthanum, strontium, yttrium, and, more recently, of xenon and caesium. It can be shown by simple considerations that this type of nuclear reaction may be described in an essentially classical way like the fission of a liquid drop, and that the fission products must fly apart with kinetic energies of the order of hundred million electron-volts each." -Lise Meitner

Now that we've observed merging neutron stars for the first time, in many different wavelengths of light as well as in gravitational waves, we've got a whole new world of data to work with. We've independently confirmed that gravitational waves are real and that we can, in fact, pinpoint their locations on the sky. We've demonstrated that merging neutron stars create short gamma ray bursts, and shown that the origin of the majority of elements heavier than the first row of transition metals comes primarily from neutron star-neutron star mergers.

This color-coded periodic table groups elements by how they were produced in the universe. Hydrogen and helium originated in the Big Bang. Heavier elements up to iron are generally forged in the cores of massive stars. The electromagnetic radiation captured from GW170817 now confirms that elements heavier than iron are synthesized in large amounts the aftermath of neutron star collisions. Image credit: Jennifer Johnson / SDSS.

But the new discovery raises a ton of questions, too. Seeing this event has presented theorists with a number of new challenges, ranging from the event rate being some ten times as great as expected to much more matter being ejected than we'd thought. And what was it that was left behind? Was it a neutron star? A black hole? Or an exotic object that's in its own class?

We knew that when two neutron stars merge, as simulated here, they create gamma-ray burst jets, as well as other electromagnetic phenomena. But whether you produce a neutron star or a black hole, as well as how much of a UV/optical counterpart is produced, should be strongly mass-dependent. Image credit: NASA / Albert Einstein Institute / Zuse Institute Berlin / M. Koppitz and L. Rezzolla.

There are some great advances that the future will hold for gravitational wave and neutron star astronomy, but it's up to theorists to explain why these objects behave as they do.

esiegel Fri, 10/20/2017 - 01:27

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Would this be one way to make a quark star? Since quarks are also fermions the Pauli Exclusion Principle ought to provide enough pressure under certain circumstances to make a star that looks like a gigantic hadron held together by gravity. Or would such a hypothetical quark star already be so dense that it would make an event horizon all by itself?

Could the omnidirectional gamma ray bursts be coming from the ejecta themselves? It seems like the process of going from a lump of neutronium to all those heavy elements is a lot like the fission reaction of an atomic bomb - just one the with the mass of 30 to 40 Jupiters.

@Anonymous Coward #1: Yes, it is possible. Two merging neutron stars close to the mass limit (about 2.5 solar masses, depending on the equation of state you like) would clearly exceed the mass limit for the final state.

Whether that final state becomes a black hole directly, or an over-mass neutron star which collapses later, or something like a quark star, depends on astrophysical details we just don't know yet. Future GW observations, including the post-merger ringdown, will give us substantial information on the mass distribution and equation of state.

GW170817 didn't show a ringdown signal; we don't know whether that's because the merger went directly to a black hole, or for some other reason.

Have the initial orbiting black holes detected by LIGO been independently observed apart from laser interferometry yet?

CFT @4.
There is really no other signal likely observable over a distance of 2 billion LYs. So the answer in theory is no. And
we don't have their location on the celestial sphere narrowed down, we don't even know which galaxy clusters to search.

That's a good reason why Ethan thinks NS mergers are where the real discoveries will lie.

CFT,

I fear you'll have to wait until EM telescope measurements are able to capture the impact of the accretion disks around two merging black holes for the independent observations you’d like. By definition there will be no EM residue from the merger of such entities, but the impact of their intersecting accretion disks (assuming both have one) is likely to be awesome!

The wikipedia entry on GW179817 says the the two LIGO sites and Virgo detected the signal.
It has images of "Time-frequency representations of data containing the gravitational-wave event" from the three sites. For the LIGO sites, a signal can be clearly seen, but for Virgo what is it on the image which represents the signal?

I'm going to regret the loss of scienceblogs: the format seems much better for viewing text contributions, which is after all largely what it's all about. I can't get on with Forbes: it's too cluttered, and wasteful of screenspace.

...sorry "GW170817"...

Why don't we have artificial gravity in space?

esiegel — Thu, 19 Oct 2017 05:00:16 +0000

Why don't we have artificial gravity in space?

"Designing a station with artificial gravity would undoubtedly be a daunting task. Space agencies would have to re-examine many reliable technologies under the light of the new forces these tools would have to endure. Space flight would have to take several steps back before moving forward again." -Andy Weir

Ever wonder, in those science fiction shows, how space travelers always stay “down” on their starship? Irrespective of acceleration, and despite the fact that the astronauts we have in orbit around Earth are weightless, they’re always depicted as having a floor and a ceiling that are well-defined, and always find themselves on the floor. This is physically impossible given the laws of physics as we know them today, but one small discovery could suddenly render artificial gravity possible.

This launch of the space shuttle Columbia in 1992 shows that acceleration isn't just instantaneous for a rocket, but occurs over a long period of time spanning many minutes. For a starship, versus a rocket, the acceleration would be many times greater, even if sustained, than a human body could withstand. Image credit: NASA.

We’ve measured the inertial mass of every particle and antiparticle we know of, and everything has positive mass/energy to it. But gravitational mass has only been measured for the particles, never for the antiparticles. There’s currently an experiment underway, the ALPHA experiment at CERN, whose goal is to measure which way antiparticles fall in a gravitational field. If they fall “down,” then they’re not the solution to artificial gravity. But if they fall “up,” this fictional technology could suddenly become real.

The possibility of having artificial gravity is tantalizing, but it is predicated on the existence of negative gravitational mass. Antimatter may be that mass, but we don't yet know, experimentally. Image credit: Rolf Landua / CERN.

We presently don’t have artificial gravity in space because there’s no such thing as a negative gravitational mass. But if we get an experimental surprise, all of that could change overnight!

esiegel Thu, 10/19/2017 - 01:00

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The only practical solution the problem of artificial gravity (that doesn't revolve around imaginary particles) has I think already been invented. We use them in medical labs. A modified swinging bucket centrifuge, as this would pretty much solve the gravity issue in multiple situations of acceleration and in orbit.
.
Solution One: The space station in orbit, A rotating area of the station or ship provides the artificial gravity (The big station in 2001 or the Discovery), but this has problems if the ship is accelerating, you would not be able to walk on the 'floor' since you would also be pushed to one side as well by the acceleration.
.
Solution Two: The ship or station is accelerating and as long as it does so, the artificial gravity due to acceleration keeps people on the floor, but the ship has to be designed with floors that keep the occupants feet towards the thrusters, and their heads towards the front of the ship, like a vertical skyscraper basically (thinking of the Chrysler Building with a rocket on the bottom comes to mind in my imagination), this is great until the ship has to start decelerating or goes into orbit where the crew will once again have to deal with weightlessness.
.
Combined solution:
When the ship is accelerating, the spinning parts of the ship or station stop spinning, the habitat modules are like the pivoting bucket test tubes in the centrifuge, they can pivot so that while under acceleration (when the centrifuge is turned off or not spinning), down is towards the thrusters, and the module pivots accordingly so like the test tube holding the sample at rest, it is in a position to take advantage of the acceleration as gravity. When the ship enters orbit, the spinning section starts up and the habitat modules pivot again, this time with their tops pointing towards the center of rotation, like the centrifuge spinning, holding the contents in the tubes.
.
The drawbacks to such a system of course is the spinning and pivoting mechanisms necessary to allow such movements, and then the engineering issues of allowing passage from such areas to other parts of the ship/station in various situations. The other major issue is balance. Even a small car tire can become a real issue if it isn't balanced. A very large ship/station would have even more trouble if it went out of balance, for one, it would wobble all over the place, or even tear itself apart. To prevent this from happening, a system to rebalance mass would be necessary. A science fiction book I read as a child proposed that water could be piped to different parts of the station into ballast tanks as necessary under careful computer guidance to keep everything balanced when things were moving about the interior of the station, this might actually be a workable solution to the balance problem.

If gravity was in space outside of earth. Then no one could afford to go to another Planet. As is if one built a Rocket ship for transporting people. Then each can run full power, then down to slow & you'd be traveling in high speed where ever. Also to talk to alien's. You must learn outside languages. Human's are Alien's even from 23 years from Earth. NASA'S Hubble Telescope while tracking an Alien Mother Ship later & I proved this to be true. Human's of different colors, cultures & languages. Also Alien's visit earth. I once received 2 question's from Alien's on Yahoo.com Answer's & answered them, but was later taken off Verizon's web site, because I'm the only expert from earth that knows the cause of Global Warming & what they look like. Global Warming has been off since May 2017 & the invaders now live on earth. Mike

I'd like to subscribe to this web site & get newsletter's from it. If this is possible, contact me at okeydokee@hughes.net

Even if anti-matter produces anti-grav, you would need a heck of a lot of it to get 1G. How much mass is needed to create 1G (depends on density, at the average density of about 5 the mass of the earth is needed. Denser matter, and you could get by with less. But, its a huge amount no matter how you do it, and presumably it is also inertial mass, which kind of makes spacecraft difficult to accelerate.

All gravity responsive forms are made so by the predominating stabilizing force of what is termed 'antigravity' that is equally as 'transparent' as the more familiar form of gravitation'. Factors so derived are also mostly largely
and essentially beyond human grasp. Even so, lingering evidences of such a factual inscrutably predominating presence, remains as ever, inviolably vast.

What I find funny about fictional artificial gravity is when they are experiencing an emergency. All life support is shut down, but they still have gravity.

@Douglas Robertson,

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I also wondered why they felt cutting life support would give themselves enough additional energy to power their shields or warp drives as well. Besides the fact they had spacesuits they could have put on, life support can be powered by actual mundane batteries on board space craft TODAY, while magic warp drives, energy weapons, and shields would take many magnitudes (more than nuclear explosions worth) more power than any form of energy production we presently have in existence. This would be the equivalent of claiming you could propel the titanic if you just transferred power from your cell phone to the engines.
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Particles with imaginary properties make for very bad science, it's like discussing 'unobtanium' with a straight face. I'll wait for observation and evidence before getting excited.

@Alby and Michael J. Schmitz,
Neither of your random word generators are very good.
You can both do better than watchout4snakes.
Try harder.

@CFT #7:
I always thought the same but now it occurred to me:
Isn't it possible they count artificial gravity as part of life support for some reason? :-)

CFT #7
"Particles with imaginary properties make for very bad science, it’s like discussing ‘unobtanium’ with a straight face. I’ll wait for observation and evidence before getting excited."

That was good for chuckle. Dry humor.
Thanks.

@Frank #9,
Oh Drat. I hate to say this but, If what happened to the Klingons on their own battle cruiser is any indication after their gravity generator was taken out (ST: The Undiscovered Country), then sadly you are correct. The space men are absolutely helpless aboard their own ships without gravity. I would have thought they would have been trained for this, or given magnetic inserts in their shoes (just in case). This just makes me think of sailors who can't swim. None of their ships are designed in any way for zero g, I don't ever notice hand holds or extra padding on their corridors or rooms...strange considering how often they get banged around from (fill in the blank) of the week. Of course...I also just considered, Sulu even tapping the gas pedal while the inertial dampeners and gravity generators were down would turn everyone onboard into a nasty wine stain on the nearest stern wall...so much for a drink. I've lost my appetite.

@CFT #11: Regarding the inertial dampeners (isn't that just lovely technobabble?), Michael Okuda used a slightly different phrase than you in the ST:TNG Technical Manual, "chunky salsa."

On a positive note, it can be good to know that the folks actually writing the shows recognize when they're short-circuiting known science.

We now know gravity is a wave. Yay. We have created other waves, sound, electromagnetic, light, wave pool at the park. As of now I don’t think we understand what creates gravity waves. If we do perhaps we will be able to create “gravity” with out exotic paticles.

@CFT #11:
Also consider the comfort level of life in space currently (always have to eat special space food for example).

Imagine how much that comfort level would increase if we could provide artificial gravity in space.

Or think about how uncomfortable a trip of months to Mars would be today versus if we could provide artificial gravity on the way. I think then a trip to Mars would become similar to taking a very long trip in a motor home or a cruise ship.

Gravity is really a basic need of human life.

@Frank #14,
I can agree about the need for artificial gravity if you are going to be space travelling for very long, but I think it would be best to address the problem with something along the lines of what we could actually do (as I suggested with a swinging bucket centrifuge type design), than holding out for someone to invent flubber.
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I remember well watching Babylon 5 (They had a LOT of spinning kinds of ships and stations!!), when the Minbari promised to teach humanity how to make artificial gravity without spinning, allowing them to accelerate and maneuver more quickly (precession might have been a problem for them)...how every human's eyes lit up with excitement. Yes It would be cool, but right now the only place such things can exist is in our gravity defying imagination, not our science.

@Frank,
This is a tad off topic, but I am presently playing a game called 'Space Engineers'. It allows you to build all manner of space craft (or ground vehicles) that follow some of the laws of physics and mechanical engineering (you can add mods that add such things as more realistic thruster physics and aerodynamics in atmosphere), and uses sandbox voxels so you can watch anything you build crash, collide, burn up on re-entry, be torn in half, etc. It did become very clear to me early on that navigating the inside of space ship in zero g is a pain in the ass, so YES, I do just plonk down a handy artificial gravity generator so I can walk my engineer about. If you attempt to move about a space ship in zero g when it moves about or is hit by something, you learn first hand what a pinball feels like (it's very disorienting).
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http://store.steampowered.com/app/244850/Space_Engineers/
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Some people have built working near full scale replicas of star ships from Star Trek, Star Wars, and other television and movies.
This won't solve the problems of anti-gravity, but it will maybe assuage your inner starship craving self that wants to fly by the seat of their pants in a craft of your own creation, or just see if you can navigate an asteroid field better than Han Solo.
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@CFT #15:
Centrifugal force may not be the only practical solution for artificial gravity. For example, for a trip to Mars, what if the spaceship has an electric space drive that can provide close to 1G acceleration continuously?

Not today but maybe someday :-) For example:

https://en.wikipedia.org/wiki/Variable_Specific_Impulse_Magnetoplasma_R…

All this discussion about"if we only had artificial grav, spacetravel would be so much nicer...
Do we need anything like 1G. Other than for conditioning out bodies, we could probably get by with .01 to .1G. Again spinning a spacecraft could do this, but the strength varies linearly with distance from the axis. Of course the psuedo grav field changes
direction as well as strength as one moves about. Might make for some interesting new ball games, where figuring out how to throw a ball to someone else would be mind-challenging.

@Frank #17,
That was why I proposed a swing bucket centrifuge. When the craft was under acceleration, it would not spin, the habitat modules (where the test tubes would be in such a centrifuge) could pivot in such a way that they could take advantage of the acceleration, and when the ship got into orbit around Mars, it could then start to spin, the buckets would pivot be able to take advantage of the centrifugal force at that point.
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https://www.thomassci.com/Equipment/Centrifuges/_/ROTOR-HIGH-CAPACITY-S…
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See where the test tubes are?, imagine that was on a much larger scale where your habitat modules would be. Under g, the buckets are vertical to the direction of gravity, when not under thrust, they could spin, the bottoms of the buckets would swing outwards to provide the correct orientation to take advantage of the rotation for artificial gravity.
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I only suggest this so the craft could have some way to provide gravity under thrust or not.

@Omega Centauri #18,
If you did spin for your artificial g, you wouldn't want your outermost level at any higher than one g, and everything above it (relatively to the axis) would be experiencing something lighter than 1g. I think you would need higher than the fraction of g you mention or human bones start to suffer bone density loss and muscles atrophy to the point the astronauts would be severely weakened by the time they reached their destination (Mars??). I think you might be able to take advantage of the lighter gravity in the inner levels for sleeping, I think I might have read somewhere that sleep in zero g has benefits.

#7#10
“Particles with imaginary properties make for very bad science, it’s like discussing ‘unobtanium’ with a straight face. I’ll wait for observation and evidence before getting excited.”

Alchemy was essentially imagined chemistry making base metals into gold until not found. Missing elements in the periodic table had imaginary properties until found. Larger nuclei fall apart quickly, even faster as they get larger, but it is theorized that if even bigger at some point they will be stable again - should we try masker them?. The ether was imaginary until, well, yes, found to be imaginary. Historically the vacuum was imagined and considered by many an abstract concept devoid of reality. Radiowaves were theorized by Maxwells equations and later produced by Hertz. The Bohr model of atoms was first imagined and greeted with disbelief. Antimatter (first proposed whimsically) had imaginary properties, then Dirac theorized antielectrons, which a few years later were found (and up to antihelium now made). Theory says antiparticles are particles traveling BACKWARDS in time - how imaginarily silly is that? The neutrino (first named jokingly) was thought so removed from reality that Nature rejected Fermis first theoretical paper on them (really, a particle that can pass several times through the earth before hitting anything - preposterous!). The Higgs boson had imaginary properties till it was found. The graviton hasn't been found yet. Tachyons have imagined properties and haven't been found, but despite that folks still look for them - wasting their time?. The strings in string theory are still imaginary. Virtual particles were imagined and we only imagine they exist because we see their effects - never seen them directly (and apparently never will). Dark matter and dark energy have imaginary properties - don't even know what it is yet - but apparently its there - maybe its not there - should we stop looking for it? The list goes on.
My favorite, obvious why:- Transparent aluminum was imaginary until it was made.

" I’ll wait for observation and evidence before getting excited"
Yea, but where you gonna look? Imagination and theory tell us what to look for, and how, and I am excited about that. Makes for great science.

BTW Unobtanium was a term initially used by scientists and engineers for decades not as a joke, but to describe a material that was difficult or costly to make.
"Later, unobtainium became an engineering term for practical materials that really exist, but are difficult to get.[4] For example, during the development of the SR-71 Blackbird spy plane, Lockheed engineers at the "Skunk Works" under Clarence "Kelly" Johnson used unobtainium as a dysphemism for titanium. Titanium allowed a higher strength-to-weight ratio at the high temperatures the Blackbird would reach, but the Soviet Union controlled its supply and was trying to deprive the US armed forces of this resource.[b]"
Some rare earth elements are still called unobtaniums in the ore industry.

The term became a joke only relatively recently in fiction, not reality. You gotta love the irony :-)

Don't see any of this giving me a chuckle.

CFT.

What? No warp drive and inertial dampness in the real world. Heresy my man!!!!!

I like the idea of a practical starship that uses acceleration for gravity and the 'Empire State' rocket. Then, half way to the destination you decelerate, giving G with everyone flipping over and standing on the roof and flipping over equipment etc. Slow, but would work.You could live without G for the short time switching from acceleration to deceleration, and for the short time in in orbit before landing. A bit dull - you pretty much only fly straight. No Starship Enterprise swooping around - sadness. At least you could turn a little but it would have to be slow, an acceptable fraction of G. Or I guess a few G's if everyone straps in for the turns.

Surely this has all been thought of before.

Or when decelerating you simply flip the ship around 180, have engines on the top too, or some way to redirect the thrust at the other end.

A friend pointed out a big science blooper in the movie Passengers.
That does the rotating thing forartifical gravity. Theres a pretty cool special effects scene where Lawrence is swimming in a pool, they loose power, the gravity stops, and she's trapped inside a large wibbly wobbly ball of water trying to swim out. I struggle visualizing how swimming would be in zero G.

That said, the artificial gravity goes away because the ring stops rotating. BUT if you've powered up the ring, and made a good virtually frictionless interface with rest of the ship, why would it stop spinning when you loose power? It should continue until a force slows it down - basic Newton.

#20
"I think I might have read somewhere that sleep in zero g has benefits."

Can you find that for me - would be interesting. I can't find any 'benefits' per se, just that many astronauts say it feels comfy since there is no pressure on the body. Comfy isn't really a benefit, since its counteracted by the 90 minute day on the space station at least, and without a normal day cycle your circadian clocks go out of whack. Apparently sleeping pills are the drug requested most by the astronauts. And theres all the other lovely things that start happening like muscle loss and retinal detachment etc.
Is it possible you've confused this with the adverts for supposed zero gravity beds on Earth, which aren't??

The astronauts on the ISS also greatly miss showers (Skylab had a shower). An important side note is that you need to sleep in a well ventilated place - without G, the CO2 you breathe out stays around you and you could suffocate!!

Why Neutron Stars, Not Black Holes, Show The Future Of Gravitational Wave Astronomy

esiegel — Tue, 17 Oct 2017 03:11:56 +0000

Why Neutron Stars, Not Black Holes, Show The Future Of Gravitational Wave Astronomy

"This is going to have a bigger impact on science and human understanding, in many ways, than the first discovery of gravitational waves. We're going to be puzzling over the observations we've made with gravitational waves and with light for years to come." -Duncan Brown

Detecting black holes and the gravitational wave signals from them was an incredible feat, but doing the same thing for neutron star mergers is a true game-changer. Instead of fractions of a second, neutron star mergers show up for up to half a minute. Unlike black holes, there’s an electromagnetic counterpart. Because of that, we can verify that the speed of gravity really is identical to the speed of light: to better than 1 part in 1,000,000,000,000,000.

All massless particles travel at the speed of light, including the photon, gluon and gravitational waves, which carry the electromagnetic, strong nuclear and gravitational interactions, respectively. Image credit: NASA / Sonoma State University / Aurora Simonnet.

And perhaps most spectacularly, we can bring the electromagnetic and gravitational-wave skies together for the first time. Even though LIGO has seen more merging black holes, the fact is that there are more merging neutron stars. The key, now, is finding them. We live at a moment where gravitational wave astronomy is just in its infancy, giving us a whole new way to look at the Universe.

The galaxy NGC 4993, located 130 million light years away, had been imaged many times before. But just after the August 17, 2017 detection of gravitational waves, a new transient source of light was seen: the optical counterpart of a neutron star-neutron star merger. Image credit: P.K. Blanchard / E. Berger / Pan-STARRS / DECam.

esiegel Mon, 10/16/2017 - 23:11

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So they shifted the frequencies of the gravitational waves to the audio so that you can 'hear' the collision.
http://www.bbc.com/news/science-environment-41650745

Do you think this is helpful or misleading?
*and was what you hear real time?"

@Steve Blackband #1: In fact, there isn't any shifting involved! LIGO's sensitivity range is right around 300 Hz (spanning a few tens of hertz up to a few kilohertz), which is exactly the range of human hearing (middle C is 256 Hz).

IF gravity traveled at the speed of light, how do you explain the actual orbits of planets around the sun? Interesting things happens if you put your propagation effects at c. Unfortunately stable planetary orbits is not one of them, orbital calculations depend upon gravity being much faster than c to nearly instantaneous in order to work at all. The Earth also orbits a location that is approximately 20 arc seconds ahead of where the sun appears in the sky, where it actually is, not where the light which we are just receiving some eight minutes later shows it to be.
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Lets get skeptical and use Occam's razor to clear the air a bit instead:
What did LIGO actually detect? The laser wiggled (effect). The effect was attributed to gravity waves (cause). It is now admitted that what was detected was propagating at c. What was actually detected? Gravity waves traveling at the speed of c, which is in disagreement with our own planet's orbit, or just an electromagnetic effect to begin with? There is also the problem that gravity travels at c in Einstein's math only because he wanted it to, the equations are coordinate dependent, you get differing speeds for gravity unless you cherry pick your coordinates specifically to get c. There has been a lot of debate on this by physicists.
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Ethan admitted the reason they could even 'detect' orbiting black holes to begin with is because they created such powerful gravitational waves. How much less powerful are the gravity waves of neutron stars? Magnitudes? Considerably? If LIGO had troubles with detecting black holes, would it not have even more trouble with detecting something far less massive? The sudden pivot to detecting orbiting neutron stars seems a bit suspect, combined with claims of c propagation for the gravity waves. In any case, something has got to give theoretically. I have no trouble picking an initial side. I'm siding with direct evidence of our own planetary motion requiring faster than c propagation of gravity, over a highly inferred and indirect evidence based off a theoretical template in a computer processed 'wiggle' of something much farther away.
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This to me seems much like the point of contention with BICEP2. Polarized dust WAS actually found (effect). Assumptions were made about (cause) how and when it was polarized. The assumptions turned out to be wrong. The tragedy of BICEP2 wasn't that it didn't turn out the way they wanted, it was that not a single purportedly brilliant person on the entire research team, or even one of their financial backers asked the obvious question the entire projected revolved around "How will we be able to discern the causes of the polarization?"
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The same obvious question is there again. "How do you know what is causing your laser to wiggle?" You have a connection between a subject (neutron stars) and your detector now, but is it what you want it to be? Or is it something more mundane?

@CFT #3: What an awesome demonstration of ignorance.

"Gravity" doesn't "travel at the speed of light," any more than a _static_ (i.e., unchanging) electric or magnetic field travels at the speed of light. If you actually studied the physics you so blithely distain, you'd already know this.

The gravitational field of the solar system is essentially fixed (the movement of the Sun's barycenter is tiny compared to the sizes of any of the planets' orbits). The same is true, of course, for the orbits of all the planetary moons about their primaries. Consequently, the orbit of the Earth and other planets is perfectly described by a Keplerian ellipse. In Newtonian language, we can say that the force between the Sun and Earth is instantaneous. In Einsteinian language, we say that the solar system metric is static to high precision. The observable outcome is the same in both cases, and in both cases can be derived quantitatively by someone who can handle the maths. Your statements demonstrate clearly that you either can't, or just don't want to because it doesn't fit your argument.

What does travel at the speed of light (as measured to within +/- half a part in 10^15) are _disturbances_ in gravity, such as gravitational waves.

The interferometer didn't "just wiggle," as your willful ignorance would have it. The mirrors (not the laser, another demonstration of your ignorance) moved in a very specific oscillatory pattern, with a frequency which increased over time in a very specific, continuous way. What is observed, measured, is not just the movement, but the very specific time history of that movement. Your sidestepping of those quantitative technical details (here as in so many other of your ranting posts) demonstrates that you are either ill-equipped to understand them, or you do understand them but deliberately confabulate in order to support a false narrative.

Uh, CFT, I think the compounding of events - Gravitational Wave, Gamma Ray Burst, and the correlated Optical detection pretty much seal it as a legitimate detection.

Going forward, there will either be more detection with all the parts, or not. The GRB within seconds of the gravitational wave detection is pretty strong evidence.

Dearest Michael,
You lost me the very moment you called me names...many months ago. I certainly would never take you seriously if you told me the sky was blue at this point. Incompetent experts such as yourself should be cleaning toilets until you develop a semblance of humility, not advising people on anything. Now please, go pound some sand.

@MK #4: " In Newtonian language, we can say that the force between the Sun and Earth is instantaneous. In Einsteinian language, we say that the solar system metric is static to high precision."

I really enjoyed that. Pick your language and your theoretical paradigm. Make your argument from that bias.

What happened to the scientific method?!

@MobiusKlein #5,
What their 'detection' reveals in terms of by optical and radio is not in contention, those are electromagnetic in nature. What they claim they are detecting on their laser seismograph is. The fact they are claiming detection of gravity waves at c means it could be something other than gravity waves. The math is not convincing me, as it does not stipulate gravity even travels at c unless you choose very specific parameters BICEP2 was claiming a positive detection at sigma 7. Do you know what the statistical odds of that being wrong are? 1 in 10 billion, and they were wrong.
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Forgive me for my skepticism, but no, I don't believe their ridiculously high claims of their calculations certainty, they aren't very credible at this point. Blowhards like Michael Kelsey having such peculiar overreactions to being questioned only further convinces me something odd is going on.
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If Michael actually was half as informed as he claims, he would have known the argument I was using to challenge the assertion of gravity waves in a vacuum traveling at light speed was actually not even mine, but someone else with considerably more expertise. In other words, he accused me of making up an actual position taken by one of the finest astrophysicists of the twentieth century who in fact worked alongside Einstein himself, A.S. Eddington.
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“The statement that in the relativity theory gravitational waves are propagated with the speed of light has,
I believe, been based entirely upon the foregoing investigation; but it will be seen that it is only true in a very
conventional sense. If coordinates are chosen so as to satisfy a certain condition which has no very clear geometrical importance, the speed is that of light; if the coordinates are slightly different the speed is altogether
different from that of light. The result stands or falls by the choice of coordinates and, so far as can be judged,
the coordinates here used were purposely introduced in order to obtain the simplification which results from
representing the propagation as occurring with the speed of light. The argument thus follows a vicious circle.”
---A.S. Eddington, The Mathematical Theory of Relativity
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As I said,
Cherry picked coordinates to get the predetermined results you want doesn't prove anything, except that it is just a math push determining your speed of gravity to be c. If you pick some other coordinates, your speed will vary.

@CFT #6 (?)
Go easy on Michael, after all he does work for you as a tax payer. Michael is an employee of a US Govt scientific institution and can provide vital input.
He can be a bit salty at times but that's understandable because of all the testosterone fostered penis measuring contest that has gone here in the past.

Men in the science community should follow some of the decent lessons from physical sports teams in our society where we disagree, give some hard hits, and then shake hands and move on. Holding long term grudges does no one ESPECIALLY the truth any justice.

If there is an undetected (by instruments, of course) omnipresent field/medium, that would explain how everything is connected and that direct connection would explain how the force of gravity could be instantaneous.Then we could throw out "spooky action at a distance" as a problem... which resulted in GR.

Notice the opening "If." Yes, I do theoretical physics too... even without credentials! (It's not illegal, except in mainstream physics) "The fabric of spacetime"... so malleable in response to mass... is a story like "the Emporer's New Clothes." Only idiots can't see it. It's the ultimate hypocrisy in science today.

No mathematical or velocity or superluminal speed need be applied to what need not move to be ever present. While such a supposition supervenes even need for an initiating isolated theoretical all inclusive big 'bang[' singularity as a hypothetical a point of origin; even such an singular originating coalescence required prior gravitational and space presence. Also, there are no "holes" in space and space is also not "black". Such seeming appearances result from telescopic limitations.
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Since there are no "holes"in sqace -nor would they be sustained by the tremendous pressures within galaxies- what is being observed is other than as hypothesized and widely accepted. What is deemed to be "black" seems so, because so does space so appear. However space also has no color.'The APPARENT darkness is due to telescopic equipment limitati0ns unable to detect and record the full spe4ctrum and breadth and origins of spatial antecedents and content.

@Ragtag Media #9,
With due respect,
I'll change my stance on Michael when he changes his tone, and learns to argue his point, not talk down. Elitist snobbery is for badly behaved aristocrats, not civil servants.

@CFT:

You need to take a good look at ALL your past/present comments in this blog before blaming anyone for talking you down!

You are obviously someone who see all discussions as a fight for personal honor. I am pretty sure other readers of this blog prefer FRIENDLY DISCUSSIONs instead!

@CFT #6:

I think that comment alone is good enough reason to get you banned from this blog you need to realize well!

"Scientific discussion"

"I do not think those words mean what you think they mean." - Inigo Montoya (paraphrased)

Steve Blackband,

Yesterday, in the Comments of the Week thread, you appeared to invite comments about the relationship between Science (primarily Physics in this blog) and Philosophy. So, at the risk of antagonizing those few remaining readers I have not yet irritated, the below is a brief reply. If I misinterpreted, please excuse this response.

Scientific Realism is, I think, better understood in a historical context. It originated as a response to Scientific Positivism/Empiricism, another interpretation of what distinguishes Science from other intellectual disciplines. That school of thought came about as the result of Einstein’s publishing of "On the Electrodynamics of Moving Bodies", his Special Theory of Relativity (SR) in 1905. Also published in 1905, "Does the Inertia of a Body Depend Upon Its Energy Content?", Einstein determined a relationship between mass and energy.

SR and E=mc^2 were Revolutionary Science, and criticized for violating Immanuel Kant's categoric scheme that was a (if not the) contemporary philosophic world view. At that time, and to many people now, the three-dimensionality of space, Euclidean geometry, and the existence of absolute simultaneity were thought to be needed to understand Nature, and none of them should be altered by empirical findings. SR delivered a shock to physicists and to scientifically minded philosophers, and did not just point out surprising new facts, nor merely require strange new concepts. It revealed a disturbing lack of clarity within familiar concepts, such as simultaneity and length.

This sets the stage for the logical positivists/empiricists. Their goal was to build a new-and-improved version of empiricism, one that would make the philosophy and the world safe for science. The central principle of logical empiricism is that any cognitively meaningfully statement must be either analytic or a claim about experience. I shall not present an exposition of what an analytic statement might be, but if you are due for some penance, feel free to ask. Science deals with facts, hence the "claim about possible experience".

Once science is rooted in just the facts, the meaningfulness of a statement depends upon verification. By verification the positivists mean a method for finding its truth or falsehood. Since to be cognitively meaningful is to be either true or false, if there is the right sort of method for testing truth or falsehood, the statement will be meaningful.

Okay. All good, clean fun, and useful in clearing away some of the underbrush of 19th century European philosophy. Clarity uber alles, eh?

Now try to shoehorn the Bag Model of Quark Confinement into a vision limited by observation. Assuming it to be true, not only are quarks unobservable, but cannot be individually observed. Is that model of (presumed) quark confinement science, or not?

Scientific Realists find ways to relax many of the constraints which the Positivists had insisted science embrace. The Realists can then say, as the Positivists cannot, that science theorizes about quarks the same way as it theorizes about macro-sized objects. So unobservable objects are, in this philosophical POV, not second-class citizens. Of course, there’s a price to be paid. The distinctive virtues that science attained, due to its tight connection to experience are forfeited, and metaphysical possibilities made possible.

Frank #14,
A personal attack is not how you respond to an answer you think is incorrect. If you disagree, say you disagree and explain why coherently, that's all.
Michael took the first shot. I responded. Every time Michael takes a kick at me under the table, I'm going to kick back twice as hard and try to make him reconsider his clumsy approach to disagreement.
..
The advice I gave him also wasn't arbitrary.
I've taken it myself.
I cleaned over 40 toilets a day when I was a teenager, I worked at a fancy hotel near Santa Barbara on the housekeeping staff, and yes it did teach humility, as I believe was my parents intention. When you come home from work exhausted and the skin on your hands is raw from having been in Brasso polish and cleaning solvent, and your back is killing you from having been bent over most of the day scrubbing and making beds, you realize this is all some people will ever know until they die, and you begin to look at the smug self-entitled folk of the world a little differently. I don't care what you know, or what your position is, If you talk down to me I'll suggest you to go scrub some toilets too. I've had to clean up after some of the biggest stars in Hollywood, quite literally, and in the process quickly lost any sense of awe I ever had with fame or celebrity. Cleaning up other people's shit does wonders for gaining perspective.

As I understand it, Einstein's General Relativity (GR) says that if our sun suddenly disappeared, it would take about 8 minutes for the lack of its gravitational effects to be felt by the Earth. However, the Sun has been in place for a long time, and it's gravitational effects have long since propagated throughout our galaxy and beyond. (As it moves with and within our galaxy the effects sweep along with that motion but so does our solar system.) (Recall that according to GR, the effects are a strong local warping of space-time that constrains the orbital motion of nearby objects. This warping may vary slightly as the Sun itself orbits the center of mass of the solar system, but a) this is not a large effe

I read at another site that the equations of GR have been used to calculate (numerically) the orbits of the planets of our solar system for the next 5 billion years, and they all stayed in the same orbits. (This assumed no outside interference.)

To continue where I was somehow interrupted:

a) this is not a significant effect compared to planet orbital radii; and b) it is a cyclic effect which is part of the existing orbits.

I will also add, there is an immense amount of evidence for GR. E.G., our GSP system would not work accurately until GR calculations were used in it.

Any premise of orig9ns need incorporate adequate inducements for such an fcvcurrence.

Any premise of origins need incorporate original inducements.
Gravity as an all pervading static state is not reasonably viewed as having once been confined singularly with space when both are diverse in function and as such not be subject to an intense coalescence, apart from some prior inducing overpowering factor. able to resolve mutual functional virtual incompatibility.

@John #16: Not irritating at all! I wish I had a good enough grounding in philosophy (and the history of philosophy) to engage in a meaningful debate. On the other hand, this is an opportunity for me to learn about stuff I have had less touch with.

You used an example to make a point that I think is not quite correct. First, in describing empiricism (which I _think_ i my own philosophical basis) you wrote, "Science deals with facts, hence the 'claim about possible experience'."

Later, using the example of the quark model, you questioned whether, in dealing with "unobservable entities," it counted as (empirical) science at all. I think this misses the point. Scientific theory deals with "unobservable entities" all the time, in many fields. Atoms, electrons, electric and magnetic fields, various energy potentials, those are all _unobservable_ in the 18th century sense of directly impinging on our senses.

The test of whether a scientific theory is empirical or not (i.e., whether it is "really science") is whether it can be used to quantitatively _predict_ observable results. QCD uses the unobservable quarks and their interactions to make definite, quantitative predictions about things like the mass of the proton, lifetimes and decay channels of various particles (yes, there's a philosophical chain of inference involved), even predicting new particle states before they were observed.

Whether the underlying invisible entities are real or not is, philosophically, an ontological problem; more pragmatically, it's a question of how well the theory actually works. We treat electric and magnetic fields as real, even though they're not directly observable to our senses, because electrodynamics works _perfectly_ every time it is applied to an observable situation, and has done so for a century and a half and counting. We treat atoms and electrons as real for the same reason. Perhaps quarks seem less real to you (and to most people) because they don't directly impact day to day life, and because QCD has only been around for fifty years?

Incompetent experts such as yourself should be cleaning toilets until you develop a semblance of humility, not advising people on anything. Now please, go pound some sand.

It's idiocy such as this that makes me happy that SWAB will cease to exist on SB (along with SB itself) at the end of the month. Enjoy Forbes, CFT.

Michael Kelsey,

"... this is an opportunity for me to learn about stuff I have had less touch with."

That's kind of you.

My (limited) exposure to physicists persuades me that philosophy and physics are seldom pursued in tandem.

In re the scientific stature of unobservables: The logical positivists were able to integrate them into Science by the use of the analytic truths which have equal standing with observables (ref prior post) in their Received View of Theories where theoretical propositions such as the bag model of quark confinement are given a partial observation interpretation by inference to their relationship to other, observable phenomena.

In contrast, you, I, and all (LOL! both) physicists I know are Popper's intellectual children.

Narad,
Look in the mirror snowflake, and then keep scrubbing. Acting snobby while blaming others is not a winning combo. You are going to have to learn to share the playground of ideas a bit, it doesn't belong to you.
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The moment Ethan had his Forbes site, this one became an afterthought, a neglected stepchild he didn't really care about anymore, and he wanted out of. Guess why?$?

@John #24,
If you are truly Popper's intellectual children, you realize the importance of falsifiability. Inflation theory, String Theory can't be falsified, at all. Sabine Hossenfelder has pointed this out to Ethan several times...and he has agreed with her in personal discussion, but then glossed over it in his PR (things are fine) narrative on this and the Forbes site.
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http://backreaction.blogspot.com/2017/10/i-totally-mean-it-inflation-ne…
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CFT,

Yes, I am comfortable with the notion that a "scientific" theory can not be proved, but it can be falsified. That criterion of falsifiability means that to be a scientific theory, the theory can and should be tested by experiment.

But what does one say about a theory that has been repeatedly tested using techniques independent of each other, and the results (observations) of those tests have been as predicted by the theory? I don’t know about you, but sooner or later I’d say it's correct, or even True, with a capital "T". I'd only start to discount its truthfulness if there started to accumulate observations that fell sufficiently far outside the theory’s prediction that they couldn’t be honestly attributed to experimental error. The first time some weird anomaly was reported, I’d go back and try to rework the observations within the theory, not instantly drop the theory, wouldn't you? Of course you would! Good physical theories are not found in the bargain bin at Walmart.

If that paragraph didn't sound vaguely familiar, it should have. Newton's law of universal gravitation produced accurate predictions for more than 200 years. When the observations (empirical tests) of the orbit of Uranus were observed to deviate from the predictions derive from that theory, first too fast and then too slow, instead of dropping the theory, in 1846 a scientist, Urbain Le Verrier, proposed the deviations could be resolved within the Newtonian theory. He suggested that the gravity of a farther, unknown planet was disturbing Uranus’orbit. He crunched the numbers (although it must have been a bitch to do back then), and Galle and d'Arrest saw Neptune where the "rethought" Newtonian theory said it was supposed to be. It wasn't until the turn of the 20th century that the illumination provided by Newtonian Physics was to be clouded by the ultraviolet catastrophe and the curious case of the missing ether.

All theories operate successfully with domains. QM, SR and GR are physical theories that are less inaccurate than Newton's. They pass many more tests. Does that make them True? Technically no, but not only are all four scientific theories, you can safely rely on them every day.

CFT,

I think you're overlooking some of Ethan's poste opinions about String Theory.

http://scienceblogs.com/startswithabang/2008/04/18/on-string-theory-fro…

Factual cosmological antecedents are not entirely telescopically observable being only inferred from keen visual observations and collaborative deductions..

@John #27,
When the 'working story' you tell yourself can't be falsified, and you can just 'change it' to agree with whatever you like, you aren't going to be able to break out of your epi-cycles. This is why I don not like group-think consensus and despise the Bayesian mindset which is turning the scientific community into a self congratulatory echo-chamber of self referential paper writers.
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There is good news for the future however:
Scientists eventually die, and someone else is going to come along who doesn't give a rat's ass about the political consensus of experts and their overly convoluted 'stories', and do something else.
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This is what happened when a couple of bicycle builders from Ohio somehow managed to figure out what the rest of the scientific community could not.
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Science advances one funeral at a time.

@Alby #29,
Try harder. Random word generators are only good for spam.

The detection of the gravitational waves produced by the merger of two neutron stars –GW170817– has allowed scientists to fix at 70 km/s per megaparsec * the value of the increase in speed of the expansion of the universe in the 130 million light years that separate us from the origin of said merger.
As these calculations approach the speed of light throughout the age of the universe, we can do the inverse calculation to determine the average increase in the velocity of expansion so that the observable universe is of the age stated by the Big Bang Theory.
The result is 300.000 km/s /(13.799/3,26) Mpc =70,820 km/s Mpc. https://molwick.com/en/gravitation/072-gravitational-waves.html#big-bang