The Science Thread

Thrasher said:

I understand the inforamation theoretic view on the universe, but the entropy / gravity angle not sure. Second Law of Thermodynamics says that a system will grow in entropy if left to itself. But growing in entropy seems contradictory to gravity where everything wants to pull together into a singularity / black hole and less entropy.

Thus the cognitive dissonance.

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I think that it's not suggesting a straightforward link between the entropy of matter and gravity, as we perceive them in the universe. More that, if you understand the specialist mathematics that describe how things work in the holographic model, there's something about the entropy of the information that describes the universe that gives rise to what we perceive as gravity.

Yes, and that's what doesn't make sense. More entropy actually counteracts gravity, so something is awry in my understanding.

Thrasher said:

Yes, and that's what doesn't make sense. More entropy actually counteracts gravity, so something is awry in my understanding.

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I think the misunderstanding comes from the term 'entropy'. I think you're thinking of thermodynamic entropy, which relates to the physical systems we're familiar with. I don't think the theory is suggesting a link between that and gravity.

But if you think of the universe as information on a holographic plane, the theory is talking about information entropy in that system, which is completely different. If I understand correctly, the idea is that it's the way information behaves in that holographic model that gives rise to what we perceive as gravity.

I am studying an article of the NY Times right now. Dating July 2010 though.

Maybe this makes sense to you?:

“For me gravity doesn’t exist,” said Dr. Verlinde, who was recently in the United States to explain himself. Not that he can’t fall down, but Dr. Verlinde is among a number of physicists who say that science has been looking at gravity the wrong way and that there is something more basic, from which gravity “emerges,” the way stock markets emerge from the collective behavior of individual investors or that elasticity emerges from the mechanics of atoms.
[…]
Think of the universe as a box of scrabble letters. There is only one way to have the letters arranged to spell out the Gettysburg Address, but an astronomical number of ways to have them spell nonsense. Shake the box and it will tend toward nonsense, disorder will increase and information will be lost as the letters shuffle toward their most probable configurations. Could this be gravity?

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There are also some youtube videos btw.

Edit:
Another quote from that article:

“Gravity,” he said recently in a talk at the Perimeter Institute, “is the thermodynamic limit of the statistical mechanics of “atoms of space-time.”
[…]
What is new, he said, is the idea that differences in entropy can be the driving mechanism behind gravity, that gravity is, as he puts it an “entropic force.”

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Here is a video where Verlinde talks about gravity:

Higher entropy in the holographic representation of the universe would be opposed by gravity, since gravity tends to make all things come together in one location and velocity, so yeah, it doesn't makes sense that higher entropy equals more gravity. I need to read those things.

Bear in mind that in this theory, there is no gravity in the holographic universe itself - it's the entropy of the information in the hologram that gives rise to what we perceive as gravity. That's what he means by "gravity doesn't exist."

I think this wiki on entropic gravity is your best bet.

https://en.m.wikipedia.org/wiki/Entropic_gravity

Youtube video, dating November the 8, 2016, with Astronomer Margot Brouwer, University Leiden, The Netherlands, who was the first to test Verlindes theory.

Link: https://m.youtube.com/watch?v=n2OOwVkKuwM

Translation, mine (Eye):
She is saying
'At the beginning of this year, I attended a meeting where Verlinde explained his entire theory for the first time. There he showed a formula that explains the effects of dark matter with just normal matter.'
Then I thought: 'Yes, I can test that'. I can find out whether his formula matches my observations'.

Matter curves space-time. This bends light from stars that are far away. How much the light bends depends on the amount of mass.
In practice light bends more than what is expected based on the amount of mass that is perceived.
So up to now scientists thougth that a sort of invisible matter was causing the extra gravity: dark matter.

Brouwer uses data from an enormous telescope in Chile to determine distortians (Eye: or does it needs to be translated with the word 'changes'?) from distant galaxies to see how the gravity is spread over the space.

'We notice more gravity than can be explained with normal matter. This may have two explanations. Either there is dark matter we can not see, or gravity works in a different way than we think it does. And this is what Erik Verlinde is telling us.'

Brouwer looked at to what degree her observations agreed with the theory of Verlinde.
And the result is?

'When I saw how good Erik Verlindes theory agreed with my data, I was very surprised. Because in Erik Verlindes theory there are no free parameters. The amount of gravity that a galaxy has in his theory is only based on the normal matter. And we see the normal matter so we know how much there is. Because of that we also know how much gravity there is.
The prediction of Erik matched exactly my observations.'

So Verlindes theory matches the observations. But does that mean that the whole idea of dark matter can now be thrown away?

'Both theories are able to explain the obervations, but with Eriks theory there are no free parameters. With dark matter you have to adjust it. It has to be 'fitted'.
I am the first that worked in this new way, testing Eriks theory with the space-time curve, and who is actually finding that the observations match his theory.
Yes, I am the first doing that.'

Thrasher said:

Higher entropy in the holographic representation of the universe would be opposed by gravity, since gravity tends to make all things come together in one location and velocity, so yeah, it doesn't makes sense that higher entropy equals more gravity. I need to read those things.

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In my own words - ha! - gravity is just like temperature an average. With temperature it is an average of the energy of atoms. In the case of gravity an average of the energy of many little still unknown substances.

@ Thrasher.
Addendum.
The small unknown particles are subject to more or less entropy, making the scale of gravity go up or down. So when there is just one point left, due to enormous entropy of these little particles, gravity is high. I don't see any contradictionary.
Well, at least that is how I understand it. But hey, who am I… Could well be I miss something big.

Information entropy of everything being at one point is small, yet gravity is high at that location. See the conundrum?

Well, the way I interpret the stuff I've seen so far - explained to the reader/listener in simple language - I interpret YOUR words the following way.

I have got a substance, I burn it. Energy (of small particles) is increasing. But the substance evaporates. And now, with temperature being so high, "it" was not increased for I see no substance, it is simply gone.

I have got an object. XYZ is increasing. But the substance has become so small, a single dot. And now, with gravity being so high, "it" was not, and can not have been increased, for I see just one small point.

Your conundrum, the way I see/understand it, is how you define "it".

counterintuitive:
The entropy of a black hole (all mass contracted in a singularity) is very high. (but there has been a lot of discussion about it)

Also the apparent "loss" of information when particles go into a black hole gives rise to problems.

see: https://en.wikipedia.org/wiki/Black_hole_information_paradox

The Emdrive is going to space.

If it pass that test, many scientists are going to be pissed. Which I find funny, they have been trying to discredit the physics model for years (because it's just a theory you know), but now that there is something that says "Newton's 3rd law is a lie" they are all "not possible".

Although, the drive might not even break that law, nobody can't really explain how it works.

NASA needs help.

Space Poop Challenge.
NASA needs a solution to collect fecal, urine, and/or menstrual waste in space for a period of 6 days. The three best ideas will be rewarded. NASA offers up to $30,000 USD in prizes.

The challenge
Competition to source a system that routes and collects human waste away from the body, hands-free, for fully suited astronauts.
[…]
Current space suits are worn for launch and entry activities and in-space activities to protect the crew from any unforeseen circumstances that the space environment can cause. A crew member could find themselves in this suit for up to 10 hours at a time nominally for launch or landing, or up to 6 days if something catastrophic happens while in space.

The old standby solution consisted of diapers, in case astronauts needed to relieve themselves. However, the diaper is only a very temporary solution, and doesn’t provide a healthy/protective option longer than one day.

[…]
What a Breakthrough Looks Like
What's needed is a system inside a space suit that collects human waste for up to 144 hours and routes it away from the body, without the use of hands. The system has to operate in the conditions of space - where solids, fluids, and gases float around in microgravity (what most of us think of as "zero gravity") and don't necessarily mix or act the way they would on earth. This system will help keep astronauts alive and healthy over 6 days, or 144 hrs.

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For more information: see the link.

Well, looks like the race for the finish line to the elixir of youth have been launched.

Breakthrough on mices, that makes you look younger and gives 30% more life expectancy (reddit thread with people arguing over the research).

and Google just put down $1.5 billions into a new company, Calico, to study aging and find a solution...eventually.

Soon they won't need us anymore (aka self-evolving and 3d printing robots are now a thing, they just can't assemble themselves yet).

Solar system found with 7 earth-size planets, 3 of them in the habitable zone; just ~40 light years away.

Apparently, the planets are so close that you see them as large as the moon in the sky (when their orbits are close) and they have tidal effects.

It must be weird to live on one of them.