Gravity’s Oldest Puzzles (Synopsis)

Every time you follow the motion of a spacecraft, moon, planet or other object through the Solar System, you're putting the theory of gravity to the test. On one hand, there's a robust set of predictions for what the behavioral motion of these bodies ought to be, while on the other there's what we actually observe. Sometimes, a mismatch indicates the need for something new, like a new planet or a new law of gravity.

Image credit: Sky & Telescope. Image credit: Sky & Telescope.

But other times, there are mundane explanations that account for these "apparent" discrepancies, such as radioactive decay, heating from the Sun or the fact that the Earth rotates on its axis. Not all the phenomena of our Solar System have been explained, however, including the flyby anomalies and the changing perigee/apogee difference of the Moon.

Image credit: NASA/JPL-Caltech, via http://www.nasa.gov/topics/universe/features/pia14093.html. Image credit: NASA/JPL-Caltech, via http://www.nasa.gov/topics/universe/features/pia14093.html.

Could there be new discoveries awaiting us on the other side of this? Find out thanks to Brian Koberlein!

More like this

I’ve been told, many times, that gravity, or at least gravitational theory, is just like evolution and evolution theory.

But I’ve never understood that, any of those times.

By See Noevo (not verified) on 18 Aug 2015 #permalink

You've repeatedly deomstrated that you don't understand anything about science sn. It's good to see you finally admit it.

Not surprising. Reading and comprehension of scientific subjects seem to be pretty low on your list of priorities.

By Michael Kelsey (not verified) on 18 Aug 2015 #permalink

I’ve been told, many times, that gravity, or at least gravitational theory, is just like evolution and evolution theory.

By whom? You claimed that gravity was, like, totes the opposite of evolution at the beginning of shockingly deplorable production numbers at RI.

Surely it can't be akin to your boneheaded objection to modern cosmology on the basis of a lack of "practical applications," since it doesn't take having all that many neurons to rub together to connect GR to GPS. Moreoever, that connection was brought up twice to you in the context of the ICRF.¹

Hell, I can find plenty of amusing garblings of GR in favor of its supporting creationism,² but not a thing corresponding to any of your normal babbling points. Given that you plainly have no interest in science³ aside from thoughtlessly dredging up what you imagine to be "zingers"⁴ and then running away,⁵ I repeat:

By whom?

Going to turn tail as usual when there don't seem to be any women around to fixate on mocking?

1a. h[]tp://scienceblogs.com/evolutionblog/2015/06/12/what-does-it-mean-to-teach-id/#comment-63553
1b. h[]tp://scienceblogs.com/insolence/2015/05/20/why-do-doctors-deny-evolution/#comment-400288

2. Creationwiki-dot-org:

Special Relativity shows that time is an integral part of the structure of the universe, and not just the perceptions of a sequence if events. The result is that anything outside the universe would be timeless or have its own time. General Relativity requires at least one additional dimension beyond space-time, this shows that there is an outside. Such an out side would be timeless and by definition, it would be what the Bible refers to as eternity.

Don't ask me.

3. More recently at RI, he's actually declared contempt for the "science-y":

h[]tp://scienceblogs.com/insolence/2015/07/27/when-the-antiabortion-movement-meets-the-antivaccine-movement/#comment-413767

4a. h[]tp://scienceblogs.com/startswithabang/2015/07/31/ask-ethan-99-how-do-we-know-the-age-of-the-universe-synopsis/#comment-563614
4b. h[]tp://scienceblogs.com/startswithabang/2015/08/13/throwback-thursday-the-evolution-of-starlight-synopsis/#comment-563995

5. You didn't even say "thank you" for being answered on the second one:
h[]tp://scienceblogs.com/startswithabang/2015/08/15/comments-of-the-week-72-on-dark-matter-black-holes-starlight-and-more/

^ Rats. The second link should've ended after "practical applications," but they both work.

^^ Heh. And I thought I could escape the moderation queue by only using two in the first place.

please visit http://wsminfo.org/faq.htm for a complete explanation of what gravity actually is. It derives from the interaction of space-time wave movement.

By seescaper (not verified) on 18 Aug 2015 #permalink

Re: the moon's anomaly. Infall or escape of matter (i.e., from collisions)? Albedo? Uneven distribution of mass? Just some thoughts. I'd guess they've already been considered but that's what sprung to my mind.

It's not perfectly on-topic but the piece made me think about the N-Body problem and how no theory can solve it, currently. How did the universe solve the N-Body problem? It seems awfully lucky if the universe only happened this one time. I wonder how it solved the problem.

By Chris Mannering (not verified) on 19 Aug 2015 #permalink

Hi See Noevo,
I think it's an interesting parallel (evolution & gravity). Most who would say that, probably just mean it in the sense gravitational systems will evolve in certain ways. That's obviously a trivial relation because the same is true for any dynamical system.
But FWIW Julian Barbour is much more into a substantial parallel. He published a really interesting paper recently in which basically he argues that gravity drives complexity. He uses the N-Body problem and replaces the usual parameters with things like vanishing energy and angular momentum which is from his 'shape dynamics'. Then he runs the simulation and finds all the most typical solutions of the N-Body problem split the future into two opposite trajectories that share the same past.
Lee Smolin also thinks the universe has evolution with Darwinian effects. As well as a number of other people.
Sorry that's the best I can offer

By Chris Mannering (not verified) on 19 Aug 2015 #permalink

How did the universe solve the N-Body problem?

Via physics interaction between the bodies.

It seems awfully lucky

Well, its as lucky as a puddle of water calculating the right shape it needs to fill the hole.

Re. Chris @ 8: Eric Chaisson at Tufts has written extensively about cosmic evolution, and a quick search on Ixquick.com will lead to a bunch of his articles for lay audiences, that in turn will lead to his peer-reviewed papers.

Interesting about Pioneer. I'd read a brief comment somewhere that there was an anomalous finding, but not that it had been solved. If I had to guess, I would have attributed it to interactions with other relatively small objects along its path. I never would have expected stray radiation from its RTG.

Hi Eric - thanks for your response by the way. I'm not saying you are wrong, but I don't understand the dynamic you refer to. You are saying objects can be thrown together and gravity will create stable orbits?
Or is it that objects are thrown together and mostly they collide chaotically but eventually some are left that happen to be right for stable orbits?
But I mean, that would suggest stable systems are easy-to-happen. Is there any reason why that would be assumed? The exo-planets seem to be suggesting stable planetary systems are hard-to-happen.

By Chris Mannering (not verified) on 19 Aug 2015 #permalink

G - thanks I'll check it out

By Chris Mannering (not verified) on 19 Aug 2015 #permalink

from the piece "We’ve observed, for example, that the Moon’s average distance increases by about 3.8 centimeters per year as tidal interactions between the Earth and Moon transfer angular momentum to the Moon."

What's the best way to express the transfer of angular momentum from Earth-to-Moon in terms of enegy? Sorry if that's a stupid question. But could you help?

By Chris Mannering (not verified) on 19 Aug 2015 #permalink

@13:

But I mean, that would suggest stable systems are easy-to-happen. Is there any reason why that would be assumed?

I don't think its assumed, I think its predicted based on our understanding of physics. Maybe Ethan or someone else with a simulation handy can talk more about this, but if you start with a giant interstellar molecular cloud with some Brownian-like motion, gravity, etc. then more than likely you're going to get some stable system of star and planets out of it. Predicting exactly where and how many planets you get might be hard and the odds of a specific result might be very low, but the odds of some multi-body result I expect is very high. Perhaps this is a case of "random distribution is not even distribution." You seem to expect that the random banging about of this big gas could will yield a relatively uniform distribution of mass (i.e., no planets). In reality, I bet the more statistically likely result is probably something closer to a power law distribution; some big clumps (i.e. one star, some planets) and a lot more little ones

The exo-planets seem to be suggesting stable planetary systems are hard-to-happen.

Not according to Wikipedia (I know, not the best reference). Their article on exoplanets says we're finding an average of one planet per star. "one planet" makes for a 2-body system not a 3-body system, I know, but its just an average; it means we're finding many multi-body star systems as well as some sun-only systems. So empirically it doesn't seem to be as improbable as you think it is.

Though I think its definitely an interesting subject about which I'd like to know more. How many systems have we surveyed long enough to definitively say "this one doesn't have planets?" What's the ratio of systems with planets to that number? Am I way off in thinking mass might be distributed via a power law (or similar)? And going back to the simulation question, if we start with an interstellar cloud and let gravity does its work, just how often do our best models predict we'll get a planetary system? 1% of the time? 99%? Do our best simulations match what we find in exoplanet searches?

There are lots of interesting questions here... but IMO simply no rational way we can look at the data we have now and claim planetary systems are "awfully lucky." If you posit "not enough data" you can't get there, and if you use the data we have, you can't get there.

I appreciate what you say. I'll need to study what you say for longer than I have so far. Just to mention one thing about the exo-planets. It's true they find one planet. And very often that one planet is huge and close to the star. Which suggests there may have a catastrophic 'sweep up' of the whole system into that super Jupiter. It's just a possibility but the observation is hard to explain

By Chris Mannering (not verified) on 19 Aug 2015 #permalink

To Chris Mannering #10:

When I said I’ve been told many times that gravity, or at least gravitational theory, is just like evolution and evolution theory, and that I’ve never understood that, I kind of meant the following:

Although gravity is still a puzzle or mystery…
1)Gravity’s behavior can be *precisely described mathematically*, unlike evolution.
2)Gravity’s effects have been *known and experienced* by all living things throughout history, unlike evolution.
3)Gravitational theories are fewer in number, *perhaps*, than evolutionary theories.

By See Noevo (not verified) on 19 Aug 2015 #permalink

Oh, sn, you just tripled down on your stupidity.

@ SN #18

and if only that someone told you that one is a biological theory and other physical, and that those are different scientific disciplines and not to be mixed.. imagine your knowledge then...

it still doesn't make your comments any better.. but heck.. one day you might actually start using your brain for yourself

By Sinisa Lazarek (not verified) on 19 Aug 2015 #permalink

To Sinisa Lazarek #20:

So then, you would object to someone comparing the acceptance of evolution and evolutionary theory to our acceptance of gravity and gravity theory.
Perhaps for different reasons than me, but you would at least object.

Well, I guess that’s at least some progress.

By See Noevo (not verified) on 19 Aug 2015 #permalink

As ever it all depends on the details of what you are actually visualizing or saying, but that seems like a good take on things.

See Noevo says "Although gravity is still a puzzle or mystery…
1) Gravity’s behavior can be *precisely described mathematically*, unlike evolution.

- this one (number 1) is the most obviously correct of the three

2) Gravity’s effects have been *known and experienced* by all living things throughout history, unlike evolution.

-Absolutely. The word 'known' is slightly loaded for the more primitive critters, but animals and humans have a sense of gravity, and they physically experience it. This is fine.

3) Gravitational theories are fewer in number, *perhaps*, than evolutionary theories."

There probably are more evolution 'paradigms' than gravity. But there is a strong long terms consensus that whatever else is going on in evolution, basically all roads lead to Darwinian natural selection. Apart from Neutral evolution of course. But even that is basically related to natural selection.

But you're even more right if you actually break something like the 'Modern Synthesis' up into sub-theories...basically there are a great many.

I hope this helps. I'm sure you are aware but just in case....being right in this sort of way, does not necessarily strengthen or weaken the underlying hunch that you are trying to work toward. I'm curious what that is. If you're happy to answer: what do you believe?

By Chris Mannering (not verified) on 19 Aug 2015 #permalink

2) Gravity’s effects have been *known and experienced* by all living things throughout history, unlike evolution.

What are you talking about? Every time I look at my parents, I see descent with modification. Unless you are a clone of one of your parents or they're dead and thus unviewable, the same is true for you.
Every time I look at my siblings or cousins, I see differential reproductive success (some have more kids than me, some have less). And if you look around at different families, you will see the same.
Now that's two of the three (IMO) main components. I bet if you think really hard, you might be able to come up with examples of how you could view the third at work: natural selection.

p.s. You'll obviously know this but it's still worth connecting dots within a conversation even if everyone does know. So, I was going to mention that part of the significance with planetary systems is that they get massive gravitational stability for free, that a random throw-together would not. Planetary systems start from a disk, and the fact of that means they have their distance and angular momentum and direction exactly right. Obviously none of that can be counted on in the generic case.

By Chris Mannering (not verified) on 19 Aug 2015 #permalink

that was to eric

By Chris Mannering (not verified) on 19 Aug 2015 #permalink

eric says "What are you talking about? Every time I look at my parents, I see descent with modification"

He actually constrains himself to "all living things". Obviously that doesn't have to literal, but it fairly rules out theory-laden experiences of the 21st enlightened persons

By Chris Mannering (not verified) on 19 Aug 2015 #permalink

@Brian Koberlein - Thank you for writing this article. Before this article, I had never even heard of "Modified inertia by a Hubble-scale Casimir effect" (hereafter MiHsC) theory. Fascinating stuff.

If MiHsC is proven correct, its effects could explain both Dark Energy and Dark Matter without needing magic unicorn particles that no one can find. Of course, if it is real then the EmDrive could be real, and I am really doubtful on that.

@Chris Mannering #24: You wrote, "Planetary systems start from a disk, and the fact of that means they have their distance and angular momentum and direction exactly right. Obviously none of that can be counted on in the generic case."

You've still missed a bit, with that last comment. In fact, planetary systems don't "start with a disk," they start as an amorphous cloud of gas and dust, This is something which has been discussed previously in a few of Ethan's postings (probably before you started reading it!).

If you have an extended, compressible blob (i.e., gas and dust) in an environment with other gravitational sources around, that blob will experience a net torque. You can work this out yourself with some vector calculus, by starting with just one external source, then generalizing to more than one.

Once the blob is spinning, it's contraction under gravity is necessarily asymmetric. Conservation of angular momentum ensures that it will collapse more parallel to the axis of rotation than perpendicularly. This results in a spinning disk, and the further development therefrom.

By Michael Kelsey (not verified) on 19 Aug 2015 #permalink

Isn't some of the sun's mass being converted to energy. Probably not much, I realize, and probably it's pretty consistent but it would be something, right?

Add to that the blob is going to be in orbit around the galactic centre, which means stuff on one side (nearer the centre) slows down when it gets pulled in and the stuff on the other side speeds up.

Which means a decidedly marked preference to spin in the direction toward the galactic centre, and therefore form a disk.

But chris doesn't know science, only cares what he thinks he can make out as science that is wrong.

An early model Chelle. Before the insanity pepper kicked in.

" 2) Gravity’s effects have been *known and experienced* by all living things throughout history, unlike evolution."

Nope, every single living being has experienced evolution. Even if the morphology hasn't changed, they had to change to a different world with organisms that had also changed.

" How did the universe solve the N-Body problem?"

By not trying to solve it.

None of the planets bother to solve orbital mechanics to work out where it goes. It just feels the forces on it and it moves.

"Interesting about Pioneer. I’d read a brief comment somewhere that there was an anomalous finding, but not that it had been solved"

The mystery had been solved. Differential heating from the RTG causing photons to leave in a preferred direction.

To eric #23:

Me: “Gravity’s effects have been *known and experienced* by all living things throughout history, unlike evolution.”

You: “What are you talking about? Every time I look at my parents, I see descent with modification...”

Obviously, that’s not what I’m talking about.
I’d see the same thing: You probably have features resembling your parents, and they theirs, etc.

“I bet if you think really hard, you might be able to come up with examples of how you could view the third at work: natural selection.”

I don’t have to think hard at all.
Right off the top of my head I can see, for example, why snowshoe hares are prevalent in the Arctic and brown bunnies aren’t.
But I don’t see nature, no matter how furiously it “selects”, producing an ancestor common to the snowshoe hare and, say, the polar bear.

By See Noevo (not verified) on 19 Aug 2015 #permalink

"It derives from the interaction of space-time wave movement."

What do you mean by "space time wave movement"? Because that seems to be woo to me.

"Space-time warping" is sufficient and no wave or movement necessary to explain gravity. So even if the "wave movement" weren't plain old woo, it's redundant.

"Obviously, that’s not what I’m talking about."

Why?

That modification by descent is observed by EVERY LIVING ORGANISM. And it's evolution.

"But I don’t see nature, no matter how furiously it “selects”, producing an ancestor common to the snowshoe hare and, say, the polar bear."

Then go and look at a biology textbook on the phylogeny of species.

Or go to Aron Ra's youtube channel and spend a long time catching up on reality.

Chris Mannering: “Planetary systems start from a disk, and the FACT of that means they have their…”

Michael Kelsey: “You’ve still missed a bit, with that last comment. In FACT, planetary systems don’t “start with a disk,” they start as an amorphous cloud of gas and dust…”

Is that a FACT?

I seem to have read article after article over the years that says, contrary to public opinion, scientists have NOT figured out planetary formation (or star formation).

As hyperlinks here seem to be limited to less than three, here’s two quickies:

“However, the modest mass of Mars is perplexing. CURRENT THEORIES for planet formation can explain the gross features of the solar system, such as the dichotomy between its rocky and gas-rich planets, BUT THERE IS NO CONSENSUS on why Mars is almost a tenth the mass of Earth and Venus.”
http://www.sciencemag.org/content/344/6183/479.summary

(And of course, even IF they had a consensus, that doesn't mean they have the truth.)

“These systems represent YET ANOTHER NEW AND UNEXPECTED CLASS OF PLANETARY SYSTEMS and provide an opportunity to test the theories developed to explain the properties of giant exoplanets. Presently, we have LIMITED KNOWLEDGE ABOUT SUCH PLANETARY SYSTEMS, mostly about their sizes and orbital periods… Between TTVs, improved Doppler surveys, high-contrast imaging campaigns, and microlensing surveys, astronomers can LOOK FORWARD TO A MUCH BETTER UNDERSTANDING of planet formation in the coming decade.”
http://www.pnas.org/content/111/35/12616.abstract

By See Noevo (not verified) on 19 Aug 2015 #permalink

@ SN #21

I have no objection in comparing acceptances of a theory, but your original argument/question was basing merit of a theory on i.e. mathematical predictability of one theory vs other in two different branches of science.. can't do that m8..

By Sinisa Lazarek (not verified) on 19 Aug 2015 #permalink

I have a comment “awaiting moderation”, although I don’t know why. I kept the hyperlinks to two, and was addressing “factual” comments here about planetary formation.

By See Noevo (not verified) on 19 Aug 2015 #permalink

Two is still enough to get flagged.

And with your history of BS you really need to write what it is supposed to say so we can figure out if it's bollocks itself, bollocks from you, or valid, with what caveats.

Apparently the two hyperlinks are keeping my post “under moderation”, so I’ll try to tell you what to Google.

Take 2.

Chris Mannering: “Planetary systems start from a disk, and the FACT of that means they have their…”

Michael Kelsey: “You’ve still missed a bit, with that last comment. In FACT, planetary systems don’t “start with a disk,” they start as an amorphous cloud of gas and dust…”

Is that a FACT?

I seem to have read article after article over the years that says, contrary to public opinion, scientists have NOT figured out planetary formation (or star formation).

Here are two quickies:

“However, the modest mass of Mars is perplexing. CURRENT THEORIES for planet formation can explain the gross features of the solar system, such as the dichotomy between its rocky and gas-rich planets, BUT THERE IS NO CONSENSUS on why Mars is almost a tenth the mass of Earth and Venus.”
[Source: Google “Forming Terrestrial Planets+may 2014”]

(And of course, even IF they had a consensus, that doesn’t mean they have the truth.)

“These systems represent YET ANOTHER NEW AND UNEXPECTED CLASS OF PLANETARY SYSTEMS and provide an opportunity to test the theories developed to explain the properties of giant exoplanets. Presently, we have LIMITED KNOWLEDGE ABOUT SUCH PLANETARY SYSTEMS, mostly about their sizes and orbital periods… Between TTVs, improved Doppler surveys, high-contrast imaging campaigns, and microlensing surveys, astronomers can LOOK FORWARD TO A MUCH BETTER UNDERSTANDING of planet formation in the coming decade.”
[Source: Google “pnas+Architectures of planetary systems and implications for their formation”]

By See Noevo (not verified) on 19 Aug 2015 #permalink

@See Noknowledge #41: Once again, your inability to actually read or comprehend scientific articles shows through. The articles you "quote" have nothing to do with my statement about stellar systems forming from amorphous clouds. They are addressing the very late stages and fine details of planet formation, issues like relative sizes of planets, relative orbital positions, etc.

The basic physics of how to get from an amorphous, non-spherical cloud of gas and dust down to a nearly coplanar set of small bodies orbiting a star is extremely well understood and is entirely non-controversial. Except, of course, to ignorant science-deniers like yourself.

By Michael Kelsey (not verified) on 19 Aug 2015 #permalink

Chris @24 and @26: I've read these posts a few times now, and I'm not sure what point you're trying to make. As Michael and Wow have pointed out, it isn't highly improbable that you'll get first a flattened disk and then concentrations of rotating masses, that is AIUI highly probable given the forces involved and somewhat random distribution of matter you start with. Beyond that, I don't know what to add because I'm not sure what you're asking.

SN:

But I don’t see nature, no matter how furiously it “selects”, producing an ancestor common to the snowshoe hare and, say, the polar bear.

Nor will you. How could it "produce" an ancestor? That's a ridiculous request. Next you will tell me that the fact that chickens don't occasionally give birth to dinosaurs is evidence against evolution.

In any event, the theory of evolution is that species descend with modification via random mutation and (mostly) natural selection, which works on the variations produced by mutation and sexual reproduction with the result of differential success in breeding, which leads to a change in allele frequencies across generations. With the exception of genetic mutation and alleles which you can only see with some fairly advanced tools, you can see all the rest with your own eyeballs happening around you all the time. You see evolution. No, you don't see saltation, meaning the sudden appearance of hugely different organisms from a parent organism (no bear-rabbit intermediate will be born to a rabbit). But that is not a problem for evolutionary theory, because evolution does not predict that saltation happens. I have told you this several times across several different posts. Creationism, OTOH, does claim special creation which is a form of saltation. And YEC creationism further requires a form of saltation call hyperevolution to get from Noah's minimal collection of species to the millions we see today. So really the lack of any saltational change is a strike against creationism, not evolution. The fact that there are no 'hopeful monsters' is a problem for your ideas, not for mainstream evolution.

Indeed, eric, where is the evidence for any creation by god?

I did all of that years ago and am tired. Never again.

And I did it when nobody was looking. Well nobody I couldn't get some credulous thugs to beat up and kill and believe it was good.

"Is that a FACT?"

Yes.

"I seem to have read article after article over the years that says"

Yet you haven't considered your reading comprehension to be at fault, only every other more intelligent person on the planet.

To Michael Kelsey #43:

“Once again, your inability to actually read or comprehend scientific articles shows through. The articles you “quote” have nothing to do with my statement about stellar systems forming from amorphous clouds… The basic physics of how to get from an amorphous, non-spherical cloud of gas and dust down to a nearly coplanar set of small bodies orbiting a star is extremely well understood and is entirely non-controversial. Except, of course, to ignorant science-deniers like yourself.”
………………….
I think there might be many scientists who might disagree with you, Michael.

Here are excerpts from a fairly recent piece:
“The discovery of thousands of star systems WILDLY DIFFERENT from our own has DEMOLISHED IDEAS ABOUT HOW PLANETS FORM. Astronomers are SEARCHING FOR A WHOLE NEW THEORY.”

“The findings have triggered CONTROVERSY and CONFUSION, as astronomers struggle to work out what the old theory was missing…”

“THE FIELD in its current state “DOESN’T MAKE MUCH SENSE”

“… researchers continue to nurture THEIR MESS OF MODELS, which have grown almost as exotic and plentiful as the planets they seek to explain. And if the CURRENT THEORIES ARE DISJOINTED, AD HOC no longer beautiful, that is often how science proceeds…”

http://www.nature.com/news/astronomy-planets-in-chaos-1.15480

By See Noevo (not verified) on 20 Aug 2015 #permalink

"I think there might be many scientists who might disagree with you, Michael."

Hmm. And there we were thinking that you say that science isn't a popularity contest...

Your quotemining indicates that the problem REALLY IS your lack of comprehension, not the science.

Here are some other quotes that you seem not to have read:

"Some looped around their stars' poles. Planetary systems, it seemed, could take any shape that did not violate the laws of physics."

"Interaction
If two growing planets have a close encounter, their mutual gravity could sling them off in odd directions"

"Migration
A gas giant might lose orbital energy and spiral in"

But they both start off with the same genesis, the same genesis as you've been told here and refused to understand or acknowledge.

"In the search for an overarching theory, astronomers do agree that core accretion has some things right:"

"At that point gravity takes over, and the planetesimals collide, fragment, mash together and grow into full-sized planets. As that happens, friction with the surrounding gas forces them into almost circular orbits."

"The question is how to account for all this planetary-system diversity. In general, astronomers begin with the standard core-accretion theory then add in processes that probably did not play out in our own Solar System."

"says Winn: some of the smallest, closest-in planets might actually be the stripped cores of migrating giants that came too close to their stars and got their gas blown off"

"“Super-Earths are probably not nice, stereotypical birds,” says Eric Ford,"

"Observations of exoplanets are seriously biased: neither of the two main techniques would find our widely spread-out Solar System, nor are they sensitive to systems with both large and small planets. It might be that we are not unusual at all."

Hmmm. Not so much proving us wrong, but that you're lying.

"Nor will you. How could it “produce” an ancestor? That’s a ridiculous request."

It's a bit like throwing a large Ming vase at the wall as hard as possible and then looking at the tiny fragments and dust and proclaiming "There's no way this dust and these chips could have a common ancestor! they look totally different!"

Or looking a the debris and claiming "The only way to get this distribution of dust and chips is from a Ming vase! Therefore the dust over there on the top of the wardrobe must be from another Ming vase!"

The common ancestor of the hare and the bear have many many characteristics in common:

Breasts and breastfeeding.
Chordate
Bilateral symmetry
Late developing teeth
Fur
fivefold symmetry for all four appendage endings
Radius and ulna
Tibia and fibia
Mandible
Hell, lets just say you could computer manipulate the image of the skeleton of one and by merely stretching and slight bending of the bones (no deletions), you'd get a skeleton looking like the other.
Red blood cells.
Placenta
Uterus
Liver
Lungs
Hell, lets just say internal organs are identical apart from mechanical requirements for the body size.
90-ish % identical DNA genome.

Since they have so very much in common, why so much redundancy if they didn't descend from some common stock previously?

Hi Michel Kelsey #28 - thanks for replying to me it's appreciated. You said
"If you have an extended, compressible blob (i.e., gas and dust) in an environment with other gravitational sources around, that blob will experience a net torque. You can work this out yourself with some vector calculus, by starting with just one external source, then generalizing to more than one."

I'm very interested in molecular clouds at the moment, so I'd like to do this derivation....but I don't seem to know where to begin. If you come across a link that examples this I'd love to have a butchers!

By Chris Mannering (not verified) on 20 Aug 2015 #permalink

Hi eric #44 - that's fine...I'll have a go at clarifying the point (if I can find one)
You know that you refer here to two different subjects in #24 and #26? And I'm not connected with what you say below "SN" (which is probably someone's initials so that's fine.
In #24 we had exchanged after I had wondered aloud how nature solved the N-Body problem. Your view was that the intrinsic forces acting between bodies resolved the problem. I don't know if that's right or not obviously or I wouldn't have been wondering in the first place. But I questioned why it would be assumed easy to happen, that stable orbits would emerge if you threw a lot of mass together. So that's the background.
The point in #24 was that planetary systems get a lot of stability for free from the disk (and amorphous cloud beforehand) and yet what we're finding with exo-systems is possibly that most systems are chaotic and show signs of a catastrophic 'roll up' of all the planets into a superjupiter very near to the star.
So the point was just that even with substantial stability for free, which you don't get if throw a new universe together, planetary systems don't seem to end up with a stable situation, a lot of the time. I hope that helps.

#26 was about your criticism of the guy with the offbeat agenda. He said evolution was different than gravity because all creatures that ever lived had known and experienced gravity. I don't actually know what he was driving at, but anyway what I said to you was that, in stipulating all creatures, he was logically constraining his only to those generic qualities that can actually be shared by all creatures that ever lived. So that makes his point actually very weak, depending what he wants to do with it. It's a very minimal sort of point. But in doing that it's also less risky...because it does not claim anything at all in terms of what a human may come to understand. Only that humans know gravity in the sense that animals do, and experience gravity in the sense that animals do. Hope that helps. Sorry it's so long.

By Chris Mannering (not verified) on 20 Aug 2015 #permalink

Hi See Noevo - FWIW you are - probably not deliberately - being a little destructive in the way you are deploying the fact that there's likely or actually rather a lot that isn't understood.

It's fine to say that, and I think it should always be kept in mind. But it's not legitimate to throw at the other legitimate component, which is 'what is the best explanation in science right now'. When you throw the mysteries at that, it's not rational for the simple reason, there may always be a large amount that isn't explained. But science has to go onward, and it's our best guess. We put the best people possible with the best training possible, into jobs to try to improbe the knowledge., That's expensive and it wouldn't make sense to then tell them to shut up because there's still some mystery.

The distinction between what you are doing and what a lot of people do, which is they maintain a sceptical position as to any final truth. But it's ok to state best current knowledge as fact. Just not ok to really believe it is a fact. Unless it is, which it might be sometimes.

By Chris Mannering (not verified) on 20 Aug 2015 #permalink

Chris:

The point in #24 was that planetary systems get a lot of stability for free from the disk

I don't understand "for free." 'Stability' is not a physical quantity the way energy or momentum is. I'm not sure you even have a quantitative definition for it. How do I calculate the stability of a 2-body vs. an 8-body system? Does it matter if the 8-body system lasts longer than the 2-body system? What if the reverse is true, does that matter for calculated stability? Nor is it some sort of catastrophe if a big Jupiter forms. That is not necessarily more or less stable than an 8-body system; it depends on how you define stable.

I really don't understand what you think we should see around stars but don't (or maybe what we don't see, but you think we should). I also don't understand how you arrived at an assessed low probability for what we do see.

in stipulating all creatures, he was logically constraining his only to those generic qualities that can actually be shared by all creatures that ever lived. So that makes his point actually very weak

I agree SN (See Noevo...See No Evolution, get it?)'s comments are fairly weak. But in this case I don't see any reason to nitpick over his/her word choice. If he doesn't think evolution is observed, I'll tell him how he and pretty much everyone reading this could observe it. What he really thinks he ought to see if evolution is true is saltation, but as I've tried to tell him several times, that's because he has a very wrong view of what evolution does and how it works.

"How do I calculate the stability of a 2-body vs. an 8-body system?"

Actually, chaos theory can do that calculation, and the 2 body system can be indefinitely stable, whilst 3body and up are limited incalculability to a prediction horizon. In the case of the Solar System, IIRC, the prediction horizon is of the order of a billion years.

The Solar system will lose a planet in something of the order of a hundred million/billion years. We don't know exactly which one, but it will be one of the inner ones.

We know the orbit of Pluto for billions of years. But we don't know which side of the sun in that orbit Pluto will be in ten million.

Chris doesn't have a clue and is pulling post-hoc rationalisations out of his rectum and pretending they've been thought out.

They haven't.

"and yet what we’re finding with exo-systems is possibly that most systems are chaotic and show signs of a catastrophic ‘roll up’ of all the planets into a superjupiter very near to the star."

And yet what you're finding is being edited by you to pretend this is some problem with the accretion disk formation when the REST of the article you quoted in support (therefore must have read) claims that these oddities probably formed AFTER the circular planar disk of planetary orbitals had been created, as per theory you've been given so far.

Moreover, Michale has ALREADY told you about this error.

And I've told you twice.

However, you won't read me because you know you can't make me think you're honest here, whereas you think you can still make Michael waste his effort on you if you grovel to him. Of course, if he doesn't do what you want, you'll stop grovelling, because your thanks are 100% contingent on being patted on the head and being told you're a smart boy. It's not honest gratitude for the efforts of others to help you.

I seem to have misidentified a couple of posts to Chris that actually came from Seenowt.

Sorry, Chris.

I should have noticed the difference, though. Your posts only go up to 4, whereas SN goes all the way to Elephant.

"omit mention of the largest gravity anomaly of all"

Maybe because it's considered kookaid?

Quick look at it and it appears that this is only showing that the moon is not in a circular orbit. Nothing more is proven.

@Wow #57: I'm not entirely sure, but I think the current Internet version of that is "all the way to potato." ;-)

By Michael Kelsey (not verified) on 27 Aug 2015 #permalink

One I thought of recently: "This one goes all the way up to elephant!".

Spinal tap meets dumb.

Redundant post is redundant. Technically, this one too.

I thought I'd used "goes all the way to elephant" elsewhere.