Questions / Suggestions

re: #49, the big rip.

But there may be no definition of time well before then. If a single lepton, presuming it is actually of zero extent and not a compound object, would be unable to determine velocity, time or distance.

"In The Big Bang theory young universe expanded very quickly (cosmic inflation).
After some time inflation stopped.
Did speed changed because of the dark energy?"

Dark Energy, whatever it is, is a separate thing from the inflation field's associated energy.

Hubble's Law states that the speeds of recession of galaxies are proportional to their distance apart. How then can we use this law to calculate the age of the universe because when galaxies were close then speeds of recession would have to be zero?

Yeah. Look up "Acceleration", Jerri.

Thanks WOW. But I now think the depth of the answer I want will be in these lectures on Cosmology by Leonard Susskind on youTube.

https://www.youtube.com/watch?v=P-medYaqVak&list=PLvh0vlLitZ7c8Avsn6gUa…-

Hello, Ethan!
My question is about gravity.
As far I know, gravity have wave's properties and not so far scientists found gravity emitting.
What you think, whether the gravity have next properties as
interference, polarization etc?.. Can we create "gravity laser", for example, or can see gravitational interference?.
Thank you.

As we know, almost each particle has some size and mass. So if all particles came from Big Bang, they all were concentrated at one point. What was the size of that point and what was the mass? Was the mass the same as current Universe's mass?

Why Black Holes can't catch their own gravity field ?

Why Black Holes can't catch their own gravitational field ?
Why scientist say that Universe expands acceleratingly ?
Far away stars has more redshift than the nearest ones.
But we see far away stars more yanger than nearest ones..
So yanger the stars more redshift we get and expanding was more in the earliar times than now and slowering but not accelerating.

Why would they "catch" their own gravitational field? For that to happen, if we take the particle model of gravity, would require that some mass produce a graviton then produce another one to pull it back.

Because the rate of expansion is seen to accelerate, much like "that dragracer is accelerating" can be detected.

Far away stars have more space between to show expansion on.

Since light travels through space, what do you mean by "more yanger [sic]"?

We don't see yanger stars (younger I take it) and there's no method by which a younger star would be redshifted.

Why do scientists look at life as an accidental occurrence? Has anyone attempted to prove that Life is generated by a primal force, like the other basic forces; gravity, electromagnetism, strong force or weak force?

** Life seems to have a basic "Toolbox".

** Life provides our physical reality with an observer and observation seems to change the behavior of matter.

What if Life is the reason this reality exists and all the other "Forces" support its development?

Today there are arguments, whether time exists, is the Block Universe idea is correct or not. I thought of an experiment which may help for answers and it maybe possible to do in the near future. Imagine 2 super fast cameras side by side taking the picture of the same event. And in that moment one camera is standing still but the other is momentarily traveling at extreme speed. The event they taking picture of could be a screen bombarded by a bunch of electrons and each time an electron hits it creates a glowing spot. I think Relativity says the images should be different and Block Universe is correct. And if the images are the same that would mean only "now" exists, there is no time.

Hello, Ethan!
My question is about light.
What happens with the light at the boundary of the universe's expansion.He absorbed or reflected?
Thanks.

Dear Ethan,
If we had a hole in the center of the moon that we would throw a cent , what speed would develop cent in the center of the moon view of the acceleration value is not constant due to the proximity to the center of the moon . How to measure the acceleration of the acceleration ?

I think it is possible to change refraction index of air using (IR/UV?) laser or ultrasound. If so wouldn't it be possible to use a powerful laser scanner or phased array of ultrasonic emitters to create a giant "virtual" lens on top of an astronomical telescope to increase magnification?

I don't think I ever seen any picture that is an accurate representation of how space around looks to naked eye of astronauts. Is there such a picture anywhere?

And wouldn't it be great if NASA created a naked eye view of all space around Earth as a 360 degree hi-res image?

Ethan, I have read your post about why CDM is a much better explanation for dark matter than MOND, and it seems pretty good to me, a layman. However, until the GAIA telescope is in operation, it will be difficult to be sure. What I am curious about is why CDM and MOND should be mutually exclusive. Is it not possible that CDM is strewn widely across the cosmic void, and then falls preferentially into, and aggregates in, areas of "deep" GR curvature, thereby resulting in galaxies? Thank you for considering my question.

Hi Ethan,
I read your blog regularly and its perhaps the best science/physics blog on the internet - so thank you for sharing your thoughts through this blog!!
I have a question on black holes - can BH's have a magnetic field or charge that is due to the matter inside the BH (rather than an accretion disk) and if yes, how is it able to manifest itself outside the BH when nothing can escape it? I have read that there is an alternate proposal to how BH's are formed - MECO's (magnetic eternally collapsing objects). Is there a way to test whether this description of BH's is correct?

Ethan, I was just reading some of your older articles, and this one got me wondering:

http://scienceblogs.com/startswithabang/2013/04/12/inflation-dark-energ…

Is there a quantitative difference in the properties of the inflationary era space-time and that of our future universe scenario's where the accelerating expansion continues until every particle is causally disconnected, such as in the 'big-rip' scenario, or in certain regions of the 'constant dark energy' scenario?

At some point, I imagine, there would be no reference for the space-time to know it is expanding, so I was also wondering how a quantum fluctuation would behave in such an environment?

There is no difference in the present space and the future space.

The Universe is not expanding! The Universe is stationary. Current Theory, Big Bang and Inflation and General Relativity are obsolete. The Universe is a Quaternion Space, ala William Hamilton. one real dimension and three vector dimensions. Einstein's Space Time is 2 reals and one vector ict.

The real Law of Gravity is
W=[c,V][,P]=[-v.p,cP]=[-mGM/r, cP]

The Gravitational Energy W is a Quaternion, the real energy is -mGM/r and the vector energy cP=cmV is the so-called "Dark Energy".

The University is Stationary at v=c.
0=XW=[d/dr,Del][-vp,cP]=[vp/r -cDel.P, cdP/dr - Del vp]

c^2=GM/R
Hubbles Constant H=c/R=c/cT=1/T , T=Age.

Using H=62km/s/Mpc= c/R gives R=150GPm and T= 500MGs = 15.844 Gyears.

The Mass of the Universe is 2.025E53 kg..

The Density is 60E-27kg/m^3

There is no Dark Matter, the over rotation in Galaxies is due to electromagnetism, homopolar motor, like wattmeter in homes..

Dark Energy, the vector energy cP, is the driver of the over rotation, Suns are charged positive; gravity rotation causes the charged suns to create a current. The current creates a magnetic B field perpendicular to the plane. Electrons from inter-space flows into the galaxy and crates a vectro force on the suns.. F=CxP/r =eVxB.
p=eBt=euI thus mV=euI and
V=(r/m)uI=176G.1.25u I=220kmI/s thus V=220km/s with i=1 Amp. 250 suns will create 1Amp at 220km/s @8.5kpc.

Dark Energy is cP and clarifies Physics.
The Law of Force is
F= XW=[d/dr,Del][-vp,cP]
F =[vp/r + cDel.P, cdP/dr - Del vp + cDelxP]

This force includes point masses, solar systems, galaxies and Clusters and Super clusters.

Please find my question, I hope it really interesting!

If we have a hypothetical material that is very durable, in the cube with the size of 10x10x10 meters. To move it, we need to spent X energy.
But if we form it to the ultra-thin stick, a few light-seconds in length, and will try to move - what happens?
If we move the stick, its other end will move immediately, or through those few seconds, distorting space?
Or to increase the amount of energy to be applied?
Or such a hypothetical material is impossible?
Or ?

There is no difference in the present space and the future space.

The Universe is not expanding! The Universe is stationary.

That's the sort of complete bollocks that is why Trump really isn't a problem. Compared to many americans living there, trump's just a normal crackpot, like Wendull here.

Sergeii:

It will move delayed, because the force, no matter how dense and solid the material, cannot be felt faster than the speed of light.

But why is that odd to think about? What was obscure that you were surprised at it?

#60. WOW. August 18. 2016.

... Since light travels through space, what do you mean by "more yanger [sic]"?

Sorry my English, but my question quite claear - "yanger - younger - more earlier to the past. According to your own Big-Bang theory more distant objects are more earlier to the past .And they have bigger red-shift by Hubble's law than nearest ones. So the direction of acseleration of expanding is to the past and we have deselerating of expanding to the present.

Vicky, Black Holes, BH, have a magnetic field. The field is the result of charged masses revolving around the BH. The BH is nothing but the center of the revolving masses.
The magnetic filed B= uI/r, where the current
I =sum of charged masses x Velocity/2pi r.. The larger the charges the larger the magnetic field, B. The magnetic field can be intense and electromagnetic jets shoot out of the BH and breakdown matter around the BH.

Magnetic fields are the result of gravitational rotation of charged masses. Most suns are positively charged masses. Moving charges make magnetic fields, B=uI/r.

Black Holes are no more or no less than this.

" So the direction of acseleration of expanding is to the past and we have deselerating of expanding to the present."

BTW, yes, I did consider it was younger and took it as such, hence I used the word correctly spelt. But it shows an endemic problem that you need to address, and your only option is to go to some native speaker and ask them, because this is yet another claim that is either gibberish because you are unable to communicate fluently in English or gibberish because the idea you have is complete gibberish.

And the only thing I can go in is the words.

There is no direction to acceleration in time. There's past acceleration and future acceleration and you can have the time derivative of acceleration, but the claim you made is nonsensical.

But to the second part, you are wrong: acceleration is increasing, all information we have now is that it SHOULD be slowing down its acceleration, but it is increasing. And so we posit "dark energy" to fit the evidence, rather than fit evidence to our theories.

So two things:
1) Look up dark energy
2) Discuss first with a speaker of your native tongue. They DO exist on the internet, you'll have to put your language or country in the search bar, because by default it will use English speaking sites.

#77. Thank you for adressing me to my native language sector of internet. So I haven't any need to read you foolish comments. Notice , my question was addressed to Eathan, not for you. Or is that you , mr. Eathan ? And I don't know how you comment appeares in August 18. This time there wasn't. It appeares rescently.
You are the only one , who didn't understand my post.
You have not you own arguments redirectiring to the other sites.
And instead the discussing the problem , you speak about my spelling. You are usual trickiman.
...No direction of the time ?!
This describes you full.. Sorry. Good by !
P.S. этот журнал читают не только те , чей родной язык английский. А также и люди из других стран.
И им наплевать на правильное произношение.
This journal read people of many foreghn countries, their native language is not english and they don not care of it.
I wrote my article for open minded people, not for you.

"#77. Thank you for adressing me to my native language sector of internet. So I haven’t any need to read you foolish comments"

Just like we have no need to care whether you get answered or not. We DEFINITELY don't need to both interpret your language into something coherent AND work out how to mangle our own language so you;ll comprehend the answer.

If you don't want to try, don't.

But we don't have to try either.

Enjoy your deliberately cultivated ignorance because to do otherwise would be too hard.

Big question: Inflation and Dark Energy could be the same thing?

Big question: If Dark Energy causing Universe to expand, isn't it getting spent? (How total amount of Dark Energy changed since the Big Bang? Stayed same/increased/decreased?)

Not rally a GR question, but you said the graviton, should it exist, will have zero mass and spin two. How can something of zero mass have a spin?

@Michael Shain #82: "Spin" in this context is not like a top spinning around on its tip. It is a quantum mechanical property, a form of intrinsic angular momentum which doesn't require the entity to have mass (or radius, for that matter).

Spin only appears in multiples of h-bar/2 (Planck's constant divided by 4pi). We physicists don't like carrying around the same constant in all of our expressions, so we drop the h-bar and talk about "spin-1/2", "spin-1", "spin-2", "spin-5/2", etc.

First, excuse my English.
Second… let's imagine we made a 50km deep crater in Mars ^_^
We dig a 50km shaft mine somewhere on martian equator, assemble a thermonuclear bomb on it's bottom, and make a REALLY BIG KABOOM, comparable to Chicxulub impactor. How many megatons we should have? What side effects we'll cause? What atmosphere we'll have in the bottom of the crater afterwards? How long it'll stay and is it a tolerable way to colonize planets (OK, local parts of them)?

Could space-time be some kind of fluid?
It has any known fluid properties/behaviors?
And how about electric/magnetic fields or Dark Energy/Matter?

@ Frank

spacetime does have certain physical properties, and yes, you can to a certain extent make parallels with some fluid behavior. But unlike a fluid, it doesn't have a "flow" to it.. or some preferred direction of movement. But it can stretch, bend, deform in any number of ways depending on matter/energy content in it. Those gradients could be thought as temperature gradients in a fluid. Light will bend and curve when passing through fluid with different density or temperatures. Just like it bends and curves when passing with regions with different spatial curvatures.

But there is no quanta for spacetime.. at least not yet.

No, it's not a fluid and doesn't act like it. Neither does dark energy or matter, frank.

Hello, Eathan.
Is it connected to the reallyty?
https://www.youtube.com/watch?v=ClVwfryyyJo

How does our solar system go through the space?

Thanks you.

@Ethan: Have you been told about any problems with Forbes? Starting late last week, my Safari session (with or without AdBlocker) comes up with an error message "cannot parse response" on any Forbes page, including their top level, Starts With A Bang, Uncertain Principles, or anything else.

It's clearly not a problem with your blog there, but I hoped maybe they had notified you of a "service interruption."

Dear Ethan,

If the total energy of an atom is the sum of it's kinetic + potential + internal energies, where the internal energy is due to it's structure, what is the internal energy of an elementary particle?

My guess is that the "internal energy" is actually the sum of various potential energies, but thought I'd ask.

Thanks,
Brian

Ethan:
I think you should write an article titled "Is Future Predictable?"
I think it is both. The future is unpredictable in micro (quantum) scale but it is predictable in macro (relativity) scale. There are already 2d/3d cellular automata used for fluid simulation which show the exact same situation: FHP and LBM.
http://fb36blog.blogspot.com/2017/03/is-future-predictable.html

Ethan:
Stop writing articles about fluff for a second and write the article I just told you! (Just kidding don't get mad :-)

If I understand correctly from what I read and have seen on TV, the universe is about 13-14 billion years old. The energy we detect from the edge of the observable universe is in the form of microwaves and took that long to reach earth which gives us the age of the universe. But if it took that long to get here, why isn't the universe twice that age since it should have taken that long to get "there?" I know my reasoning must be wrong but don't know enough to understand why. I am thinking from an earth-centric perspective and don't know how to factor in the expansion of the universe soon after the big bang which I think I read was faster than the speed of light. I don't know if you respond via e-mail or post a response in your blog. So I am going to check the box below to notify me via e-mail. Thanks for giving my question some attention.

@ Jordan

Calculating the age of the universe isn't a simple thing. We don't really have a "device" that tells you how "old" a photon you just detected is.

Calculating the age of the universe is done by comparing various cosmological parameters that we can measure with other measurements that we do here on earth.

For a detailed article you can look here: https://en.wikipedia.org/wiki/Age_of_the_universe

on the other hand, you can use a "search" function here on Ethan's blog to search through older posts. That topic has been covered on several occasions.

Prior to the discovery of exoplanets there was an argument that cooler stars (later than about F5) had planets because they had low angular momentum, while the hotter stars spun much faster. Has the predicted dearth of planets around O, B, A stars held up?

A photon leaves a star and travels a few billion light years to earth. It is observed on earth as red shifted. That is, it has much lower energy than it had when it left the star a few billion years ago. As time does not exist for a photon, where did the missing energy go? Conservation of energy says it must be someplace.

@Ethan (or anyone interested):
Here are my ideas on Physics Of Star Trek, open to comment on startswithabang:
http://fb36blog.blogspot.com/2017/07/physics-of-star-trek.html

@Ethan:
Can a "new force"(https://arxiv.org/abs/1704.03577) be an alternative to the effect that is connected with a dark matter?

Gravity is a little big bigger than in Newton’s law; it increases with speed where the maximum is the double gravity in the case of light.
Global Physics also predicts the anomalous precession of Mercury’s orbit as Paul Gerber did 20 years before Einstein. http://www.molwick.com/en/gravitation/077-mercury-orbit.html