Tug of war around gravity

Tug of war around gravity
Spinoza Laureate Erik Verlinde. Credit: Willeke Duijvekam

In the summer of 2009, theoretical physicist Erik Verlinde had a brainwave that developed into a radical new idea about gravity and the universe as an ocean of information. Ten years later, the last word about this has not yet been said.

Spinoza Laureate Erik Verlinde says he can understand that a lot of people had difficulty with the radical idea he proposed ten years ago. Gravity is not the invisible pulling force of Newton or the curved space-time of Einstein. Gravity arises due to the reallocation of information in the universe. Verlinde still realises that it is a staggering idea that elicits an awful lot of questions.

Currently rewriting

"However a lot has happened since then too," he says in his small office at the Science Park in Amsterdam. "Over the past ten years, we have gradually learned a lot more about how you should talk about space and time information. I am seriously considering rewriting my story from 2009, but now formulated much more precisely. I think that could remove some of the scepticism that still exists."

Ten years ago, however, the newspapers and media did not doubt it for a single moment: a brand new theory about had been born. For the sake of convenience, Verlinde was called the new Einstein in news programmes and in the popular Dutch talk show De Wereld Draait Door. In retrospect, he finds that awkward. "That media hype sometimes gives rise to irritation among scientists," says theoretician Koenraad Schalm from Leiden University looking back. "The headlines were about a new theory of gravity that had been discovered, whereas Verlinde had a that still had to be elaborated and tested. The media simply do not understand that nuance, all they want is the next Einstein or Eddington on the front page."

Hypothesis, not a theory

Just like researchers at many other universities, Schalm gave a colloquium in Leiden soon after the publication to subject Verlinde's paper to closer scientific scrutiny. A nice hypothesis, but still a long way off from a theory, was the down to earth assessment. Elaborate it and, in particular, come with observations and evidence. Justifiable scepticism, Schalm still thinks. "But don't misunderstand me, it is incredibly difficult to have a really good idea in this discipline. So I have a lot of respect for Verlinde, because he has definitely given the field a new direction."

In blogs and other public media there is sometimes harsh criticism of Verlinde's work. He is accused of just floating ideas for the sake of it, providing no testable predictions, publishing too little, only being taken seriously in the Netherlands, and scarcely publishing any subsequent articles. "In all honesty, I follow that as little as possible," confesses Verlinde. He prefers to focus on specialists.

"People who all too easily say that I do not have a theory, clearly do not understand how works. You need to elaborate and test a new idea step-by-step. We must find the correct formulations and techniques." He does, however, admit that he publishes relatively little. "I have a certain preference for papers that constitute a significant step forward."

Not at all strange

"Contrary to the sceptics' opinions, Verlinde's work is definitely taken seriously," says Schalm in Leiden. "He has been cited more than 700 times. But it is very difficult material for which it is difficult to generate new results overnight." Verlinde feels that the idea that information is the deepest building block of the universe is gaining more ground.

"It is no longer as strange as it seemed ten years ago. Perhaps as a result of so much ICT we are getting more used to the idea of information. However, the problem remains that the ideas in that area have only been properly elaborated for a universe that does not expand and has an edge. For years now, I have been trying to persuade fellow theoreticians to take a better look at accelerating expanding universes without an edge, like ours. That has become a mission in itself." That would be a great idea, he thinks, even independent of his own gravitational theory.

Calculate something for once

And who is actually right? Science philosopher Sebastian de Haro from Amsterdam University College performed studies into the basic ideas in Verlinde's work. As a philosopher, he looks at them from a distance, and he can see familiar patterns in the sometimes sharp responses. "Astronomers and cosmologists are definitely interested in ideas that they can test. They always want to do that. But some string theorists still find it too vague and suggestive. Calculate something for once, is the complaint." The lesson? De Haro calls for patience and modesty. "Science costs time. People like to use big words. That easily generates misunderstandings about how gradual the process in good research really is."

Powerful information

In 2009, and to the surprise of many, string theoretician Erik Verlinde derived Newton's law of gravity from the idea that the universe is an ocean full of information. The rules that apply in this are similar to the laws of thermodynamics for gases. In the gas world, it takes effort to blow up a balloon. In the same way, a weight opposes being lifted up because that requires the supply of extra information. That opposition was found to fully accord with Newton's formula in which two masses attract each other with a force that is inversely proportional to the square of the distance. But unlike Newton, Verlinde's theory also gives an idea as to where gravity comes from.

It is an emergent force which arises from an interaction between fundamental units of information. Later, Einstein's equations for gravity could also be derived in the same manner. In addition, Verlinde developed a version for an expanding universe in which a possible explanation also emerges for the extra gravitational force that keeps rotating galaxies together. Most physicists think that this arises due to dark matter, which is made up of as yet unknown particles.


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Aug 12, 2019
Replacing perfectly good models is rather pointless, but adding an 'information' property to gravity and developing a model centering on that property is productive and not the least bit contentious.

Scientists can be so childish at times, constantly invading and attempting to annex other's intellectual territory when there are vast rich lands yet to be developed.

Aug 12, 2019
He decided gravity sources produce gravitational information (a no-brainer to everyone except five-dimensional GR cartoon-space knuckle-draggers) and since most idiots think everything involving information flow seemed to be an entropic process, he decided gravitational information flows must be entropic (he got it perfectly back-asswards the moment he tried to be constructive and innovative, in other words). A bunch of idiots gave him a prize apparently because they thought he looked a little bit like Einstein around the face.

Aug 12, 2019
To put it politely, Verlinde's formulation makes my head hurt...
Now gotta figure a way to falsify it !!

Aug 12, 2019
To put it politely, Verlinde's formulation makes my head hurt...
Now gotta figure a way to falsify it !!


Start here, perhaps;

https://phys.org/...ity.html

Aug 12, 2019
Through special relativity we know the relation between energy and mass. But where does information fits in this ? https://physicswo...-energy/

Aug 12, 2019
Spinozstein - Tug of war around gravity by Spinoza, the new Einstein

Spinozstein's gravity of space and time information
Says he can understand
That a lot of people
Had difficulty
With the radical idea
He proposed ten years ago
Gravity is not the invisible pulling force of Newton
Or the curved space-time of Einstein
Gravity arises due to the reallocation of information in the universe
Spinozstein still realises
That it is a staggering idea
That elicits an awful lot of questions

Foreth
Gravity is proportional to inertial mass
Where inertial mass is proportional to energy - E = MC²
Gravity bends electromagnetic energy
Electromagnetic energy is proportional to gravity
For as gravity bends a photon path
That photon has its quota of gravity proportional to its energy

As this reality is lightyears
From Spinozstein's gravity of space and time information
As he is now informally referred - Spinozstein

Aug 12, 2019
Some people think they know exactly how bent the entire sky should be. It gets worse. They make too much out of the only known GW-EW event. No new GW-EWs reported since. New physics messing things up? EW image not coming from the same direction as the GW signals? Something seems wrong with the silence.

Aug 12, 2019
This comment has been removed by a moderator.

Aug 12, 2019
I don't want to be too esoteric here, but gravity exploits natural randomness to create order, like the tide can sort materials into layers by gravity. Gravity is considered essential for quantum computing, cosmological models focused on gravity alone can predict where the dumb blue ox aura of dark matter effects encircle and follow normal cartoon-gravity matter around. Gravity may exploit randomness in itself to turn a spin-1 field into a spin-2 field with a concentric galactic stationary-type ripple-wave.

Aug 12, 2019
Some people think they know exactly how bent the entire sky should be. It gets worse. They make too much out of the only known GW-EW event. No new GW-EWs reported since. New physics messing things up? EW image not coming from the same direction as the GW signals? Something seems wrong with the silence.


Not sure what you're talking about. The only reason they could locate the EM signature was by triangulation from the GW signals at three detectors. By definition, it is coming from the same direction!

Aug 12, 2019
Some people think they know exactly how bent the entire sky should be. It gets worse. They make too much out of the only known GW-EW event. No new GW-EWs reported since. New physics messing things up? EW image not coming from the same direction as the GW signals? Something seems wrong with the silence.


Not sure what you're talking about. The only reason they could locate the EM signature was by triangulation from the GW signals at three detectors. By definition, it is coming from the same direction!
Also note that both H1 and L1 for LIGO and also VIRGO have been down for commissioning, the O3 run started at the end of March this year, and everyone's now back up running in 24/7 observation mode... see Update on the LIGO Detectors and the Start of O3

Aug 12, 2019
More anti-science nonsense!

Aug 12, 2019
This is a terribly, um, uninformative article. There is no hint of in what sense the highly connotative word "information" is being used. Does information depend somehow on observation or exist independently of cognition, sort of like ... dark matter, maybe? An article that leaves the reader more in the dark than when they started reading it isn't well done. This one lacks information.

Aug 12, 2019
This is a terribly, um, uninformative article

For this observation by Aretino on this lack of informing information!
Just about sums up Spinozstein's theory
These ten years in the making
Spinozstein's gravity of space and time information
For this informative question
Concerning this type of information
That can be extracted
To be transformed into the gravitational force
That keeps these stars and planets in their orbits
Fore Einstein's theory produced the gravitational force by bending the vacuum
Then there is this theory blackholes are hairy
Diminishing in mass by loosing information into this vacuum
So
Spinozstein's theory stands amongst these theories of this vacuous Aether
Foreth, we are again loosing this tenuous grip on dear old Albert
As he is now drifting out of control too this spirit world he's got to too know so well
Into this witch craft magical spiritual Aether, of this vacuous world, created in this vacuum

Aug 12, 2019
Proto - thanks. I'm looking at the front page pictures for the "O2" set. Possibly some faint wave-predictive precurser images, like with GW170104. Hadn't thought much of it before but it is maybe starting to make some sense to me. An odd idea about some GW energy hitching a ride on light while GW precursers take straighter paths.

Aug 12, 2019
when i see the word "Information" used in this article i keep thinking "Quanta"

must be my limitations of comprehension

although i am speculating without a shred of evidence...

"... Gravity arises due to the reallocation of information in the universe ..."

if we consider quanta as information?
could that help towards understanding the why of how gravity & time are so strikingly similar?
both invisible, both have a very visible physical mechanical effect on matter & energy

Aug 13, 2019
I hope this guys is right. I don't like the Dark Matter hypothesis, even though apparently it predicts a lot of stuff, i feel its a cop out due to lack of anything better.

Aug 13, 2019
I hope this guys is right. I don't like the Dark Matter hypothesis, even though apparently it predicts a lot of stuff, i feel its a cop out due to lack of anything better.


Most studies so far that have looked at this show that it doesn't match observation. Don't be putting your mortgage on it!

https://en.wikipe..._gravity

Aug 13, 2019
I hope this guys is right. I don't like the Dark Matter hypothesis, even though apparently it predicts a lot of stuff, i feel its a cop out due to lack of anything better.


Most studies so far that have looked at this show that it doesn't match observation. Don't be putting your mortgage on it!

https://en.wikipe..._gravity
Gotta admit it's pretty cool being able to derive Einstein's field equations describing relativistic gravitation just by combining the thermodynamic considerations with nothing else but the equivalence principle (paraphrasing from your link)...

Aug 13, 2019
Idiots like to abuse the ratings because they have no public logic to match their dislike of facts. Gravity is apparently entropic based on the principle that everything physical in the entire universe including gravity has to be entropic in the minds of morons who've read some media articles about Hawking radiation. Only a member of the right bunch of pigs has the privilege to take on general relativity and the obligation to gain money and empty fame plus accolades while looking absolutely stupid doing it.

Aug 13, 2019
... Gravity is apparently entropic based on the principle that everything physical in the entire universe including gravity has to be entropic in the minds of morons who've read some media articles about Hawking radiation ...
What i think is too awesome to be mere coincidence is that "intelligence" has been given a physical, scientific, mathematically rigorous form factor by way of defining it as a force, related to you guessed it, entropy, i.e.,

F = T ∇ Sτ

It scales from (or applies to) cellular automata up to human experential scales, here are some good links:

An Equation For Intelligence
Entropy, Chaos, and Intelligence
Alex Wissner-Gross: A new equation for intelligence

Aug 13, 2019
Thanks, Protoplasmix, for those links, they don't look familiar. I studied neural nets, hybrid and analog computers for a few years in the early 90's. Maybe there is still something I can use in those links to make my points on gravity in more ways. Could take a while. A glance at the first one and it rings a bell, but doesn't distinguish between gravity and E/M. I suppose intelligence is an expression of a mix of the two forces.

Aug 13, 2019
I couldn't get the 2nd link to work without some ID I don't use. Wissner-Gross seems kind of fuzzy. Muscles are entropic, neural currents are entropic, it is no surprise, and it's entirely dominated by EM in execution. Gravity is usually along for the ride there, on protons it is 10 to the 36th power weaker than electricity and electromagnetism no matter the distance, the forces there scale together in relative ratio effect regardless of distance supposedly. People are entropic because electricity and EM are entropic, gravity is not fully in control at the brief small scales of human experience but it is very consistent.

Aug 13, 2019
Protoplasmix, choices people supposedly have it in their power to make can have widely divergent consequences. If you walk past a row of motorcycles and decide to do a domino trick with them, it is more pro-entropic than restraint. The greatest amount of freedom revolves around restraint, doing nothing, it revolves around timing, in other words. I would say "playing possum" is pretty minimally pro-entropic for still being alive, but dead people may behave even more pro-entropically albeit for a shorter time.

Aug 13, 2019
I couldn't get the 2nd link to work without some ID I don't use.
hmm, might be because i have a "medium" account or their cookies, the author is Haohan Wang, try googling him with the title, website is medium.com, it keeps giving me the same link. It's a good 9 minute read, worth it.

There are some deep connections between the physics of quantum mechanical probabilities, thermodynamics, information theory, and the underlying mathematics of them ...

Aug 13, 2019
"Haohan Wang"

A neural net guy talking about maximum likelihood algorithms and statistical learning, there's someone I can relate to outside of gravity. All the learning algorithms seem to incorporate a simple "likes attract likes" gravity-like sort of adaptive synaptic weighting rule namely the Hebbian rule.

Aug 13, 2019
Quantum computers can be based on simulated annealing, it's like temperature cycling shaking the kinks out, neural net learning algorithms too, like the Boltzmann machine, it is statistical, strategically randomized in aim. Associative memory, pattern matching, matched filtering all of these approaches are partly gravity-like in essence. They're also supposed to work with noise. Noise reduction is a lot like inertia, efficient compression normally has some leftover redundancy, out-of-range parameters are the ones that jump up and back too fast. Handling noise well is considered necessary for learning.

Aug 13, 2019
Handling noise well is considered necessary for learning.
Absolutely essential for detecting gravitational waves, handling all the noise...

Aug 13, 2019
Temperature randomness in a solid or low temperature gas has residual micro-motions bouncing around some center of gravity. It's as if the random part is limited, the systematic part can be well-behaved as with low gravity it is like allowing natural micro-randomness to be sending out some useful feelers on a gentle yet unpredictable macro-landscape, working downhill.

Aug 13, 2019
Detecting gravity waves, it still amazes me. Anyway, going uphill on an energy/performance surface is like heating in annealing. Interesting but not very deep. Usually the simulating is about saving energy, finding an energy cost minimum, however, which always seems efficient and thus smart.

Aug 14, 2019
I don't want to be too esoteric here, but gravity exploits natural randomness to create order, like the tide can sort materials into layers by gravity.
Or when planets get heated up by collisions with other planets the heavy stuff sinks and the fluids and gases rise so we have water and atmosphere. And down there somewhere we find veins of gold. Or we hope. My only hiccup is associating information with order or entropy, as I typically confuse information with knowledge.

Aug 14, 2019
Detecting gravity waves, it still amazes me.
How so? Gravity waves are shock waves traveling through the medium of vacuum fluctuations. Certainly they carry some force but not what we usually think of as the force of gravity - gradients in what I call the energy density (entropy) of the vacuum fluctuations. These gradients, if they exist, are just waiting on you wherever you go. Of course the observer instantaneously drags along his own gradients just to confuse things. So the speed of gravity is essentially instantaneous.

Aug 14, 2019
The notions missing to all the above commentators are the basics of Shannon information theory and how it connects to physics. The subject is arid and abstract and I am not a specialist. One thing I can say is that it is not thermodynamics two-point-o. Information theory has wider implications; one can say that thermodynamics is information theory applied to thermal engines. For those who are interested by the subject, I suggest that you read: The information by James Gleick. https://around.co...rmation/ It is an easy book and does not tell you how it connects to physics, but it does opens up the perspective.

Aug 14, 2019
@Seeker2
Gravity waves are shock waves...
No gw are induced by gravitational quadrupoles in rotation. The earth moon combination is such a system, but their masses and rotation rate are to small for any detection to be made.

Aug 14, 2019
Detecting gravity waves, it still amazes me.


Gravitational waves. Gravity waves are a whole different thing;

https://medium.co...0743c094

Aug 14, 2019
@Seeker;

So the speed of gravity is essentially instantaneous.


Nope. This was confirmed by the simultaneous (to within ~ 1.7 s) arrival of the GWs and EM signature from the neutron star binary merger. Most scientists had always expected this, but some cranks, and a few not so cranky hypotheses, called for a difference in propagation speed between GWs and EM. Suffice to say that those hypotheses (various versions of MOND, for instance) immediately bit the dust.

Aug 14, 2019
@Castrogiovanni
Although the term gravity waves can lead to confusion, it is not erroneous. I am not asking you to take my word for it, so read this https://www.scien...adiation

Aug 14, 2019
@Castrogiovanni
Although the term gravity waves can lead to confusion, it is not erroneous. I am not asking you to take my word for it, so read this https://www.scien...adiation


Nah, not buying that. Have a look through the scientific literature (i.e. published papers). I very much doubt you will find those in the know referring to them as gravity waves. A gravity wave can occur during an earthquake. It is most certainly not a gravitational wave. The author is entitled to his opinion. But he's wrong.

Aug 14, 2019
Gravitational Waves vs. Gravity Waves: Know the Difference!
https://www.space...ves.html

Aug 14, 2019
Technocreed, I like those points. I had an analogy attempting to unify information and thermodynamic entropy, involving twigs. The main complication is that physics problems in general can have hidden dimensionality (hidden in molecular rules, e.g.), I think, and twigs can't bring that out. Anyway, if the twigs are spread around randomly and someone wants to start a fire then it's always a good idea to gather up the twigs into a pile. Beforehand there was a lot of randomness in the twig distribution and little available easily-exploitable energy, piling the twigs changed all that. Maybe I underplay more obvious human-scale links between gravity and the reduction of free energy in favor of larger scales, it's like applying gravity to a bunch of flying twigs to get them into a pile, it's not the most general case of gravity and twigs interacting on the planet.

Aug 14, 2019
@castrogiovanni
Gravitational Waves vs. Gravity Waves: Know the Difference!
I know very well what terms are used by convention. But language policing is a very anoying social behaviour and will not engage into it.

Aug 14, 2019
@castrogiovanni
Gravitational Waves vs. Gravity Waves: Know the Difference!
I know very well what terms are used by convention. But language policing is a very anoying social behaviour and will not engage into it.


It is not about language policing. It is about scientific accuracy. And this is a science site, not the local pub. Oh, and 'annoying' has two ns! :)

Aug 14, 2019
Seeker2 I appreciate your comments, I even enjoyed them mostly. I should slap my head now. GW = gravitational waves, "gravity waves" are clouds or something massive in atmospheric pressure they have inertia and do not move at light-speed, of course. I also probably should not have said "solid" and just let it drop at that at one point earlier on.

Aug 14, 2019
@castrogiovanni
Gravitational Waves vs. Gravity Waves: Know the Difference!
I know very well what terms are used by convention. But language policing is a very anoying social behaviour and will not engage into it.


It is not about language policing. It is about scientific accuracy. And this is a science site, not the local pub. Oh, and 'annoying' has two ns! :)
Ha ! When I realized that I made a mistake, my edit time was over. You can bet that have seen this one comming. English is not my first language... To put information theory in this perspective; the error rate his high because the channel bandwith is not wide enough. ;)

Aug 14, 2019
"I typically confuse information with knowledge."

To me information is more like transparency, getting out of a message whatever was put into it. Noise elimination skills can help there.

Aug 14, 2019
@castrogiovanni
Gravitational Waves vs. Gravity Waves: Know the Difference!
I know very well what terms are used by convention. But language policing is a very anoying social behaviour and will not engage into it.


It is not about language policing. It is about scientific accuracy. And this is a science site, not the local pub. Oh, and 'annoying' has two ns! :)
Ha ! When I realized that I made a mistake, my edit time was over. You can bet that have seen this one comming. English is not my first language... To put information theory in this perspective; the error rate his high because the channel bandwith is not wide enough. ;)


:) Fair enough. Your English is better than many of the native English speaking cranks on here!

Aug 14, 2019
"I typically confuse information with knowledge."

To me information is more like transparency, getting out of a message whatever was put into it. Noise elimination skills can help there.
Information is anything that can be perceived either through our senses or any other means. To bring more perspective to this comment I would add that langage in itself is coded information. You can acces the information contained if you understand the code. But coded information is only generated and used by information processors. The rest of the perceived informations comes from your interraction with your surrounding. This latest type of information have to be interpreted.

Aug 15, 2019
"I typically confuse information with knowledge."
The rest of the perceived informations comes from your interraction with your surrounding. This latest type of information have to be interpreted.
Ergo, knowledge.

Aug 15, 2019
@Seeker;
So the speed of gravity is essentially instantaneous.
Nope. This was confirmed by the simultaneous (to within ~ 1.7 s) arrival of the GWs and EM signature from the neutron star binary merger.
The latter referring to the speed of gravitational waves. The speed of the force of gravity is the instantaneous part. For example if the speed of the force of gravity traveled at the speed of light, the earth/moon system would be attracted to the sun at its position when it emitted the force about 8 minutes previosly and our orbit would quickly degrade and we would fall into the sun.

Aug 15, 2019
@Techno, @Castro, very glad you didn't decide to be impolite.

@Techno, @Castro is right; terminology is quite important. We had a demonstration of it here on this site recently, when "gravity waves" were mentioned in an article about the atmosphere, not about black holes or neutron stars or other potential sources of gravitational waves. A bunch of cranks came on blurting about astrophysics on the atmospheric physics article and got their noses pushed in; it was quite amusing to watch. Personally I always try to use the right terminology when I know it and welcome correction when it's necessary, and I recommend the same to you. Even native English speakers like me can make such mistakes (and I have).

Aug 15, 2019
The speed of the force of gravity is the instantaneous part. For example if the speed of the force of gravity traveled at the speed of light, the earth/moon system would be attracted to the sun at its position when it emitted the force about 8 minutes previosly and our orbit would quickly degrade and we would fall into the sun.

The speed of the force of gravity is not instantaneous. Yes, we are indeed attracted to the position where sun was 8 minutes go. Here's a good explanation: https://medium.co...2eb08430

Aug 15, 2019
The speed of the force of gravity is the instantaneous part. For example if the speed of the force of gravity traveled at the speed of light, the earth/moon system would be attracted to the sun at its position when it emitted the force about 8 minutes previosly and our orbit would quickly degrade and we would fall into the sun.

The speed of the force of gravity is not instantaneous. Yes, we are indeed attracted to the position where sun was 8 minutes go. Here's a good explanation: https://medium.co...2eb08430

@Seeker2: And note that the delay would not degrade the orbit; rather it would cause the ellipse to precess. However, this would not account properly for the observed precession of the orbit of Mercury, whereas it was one of the triumphs of General Relativity that its prediction did match the observed value.

KBK
Aug 15, 2019
Right at the beginning, Max Planck said it was an information field.

Egotistical humans an their bodily carrier colors things so much..that they have their reality on --totally backwards.

3d time-space is an after effect, not a fundamental.

You and all you see is a self realizing foam in the corner of a multi-dimensional pond.

Aug 15, 2019
@Da Schneib
Castro is right; terminology is quite important.
I totally agree! Using the right terminology allows for starker messages. I apply this rule, but I do not impose it to others.

Aug 15, 2019
"I typically confuse information with knowledge."
The rest of the perceived informations comes from your interraction with your surrounding. This latest type of information have to be interpreted.
Ergo, knowledge.
If a dog catch a ball, is it because he studied Newton? No! but he still processed information.

Aug 15, 2019
Suppose you have a 10-bit scrambled encrypted linear thermometer. It has 1024 possible messages, no one of the 1024 possible scrambled encrypted messages is more meaningful/significant/unusual than the others, no bit or sub-symbol of the message is more it meaningful/significant/unusual than the others, this is to say the encryption is very good, so it takes 10 yes-no guesses to guess the temperature assuming you can convert the temperature to binary code. Ten bits is the information content of such a randomized message. If you take out the encryption/scrambler then guessing the temperature can take fewer guesses since temperature variations are not completely random. Unusual temperature effects supposedly carry more information than easier-to-guess normal temperatures but that assumes a noiseless message channel.

Aug 15, 2019
@Seeker2: And note that the delay would not degrade the orbit; rather it would cause the ellipse to precess. However, this would not account properly for the observed precession of the orbit of Mercury, whereas it was one of the triumphs of General Relativity that its prediction did match the observed value.
Like frame-dragging. The distortion in the curvature of spacetime follows right along with the orbiting body. Instantaneously. In GR gravity is caused by the curvature of spacetime.

Aug 15, 2019
Total energy is usable energy, which is "free energy" (ordered energy, like stored energy, stacked energy) and unusable energy which is "entropy" (random-like, disordered, distributed energy, like ambient energy, like background energy) there is no need to go into information theory entropy here, gravity can naturally convert randomness, in the form of entropy as disordered energy, into order in the form of free energy. Gravity is "entropic" in the sense that it is anti-entropic.

Aug 15, 2019
@Seeker;
So the speed of gravity is essentially instantaneous.
Nope. This was confirmed by the simultaneous (to within ~ 1.7 s) arrival of the GWs and EM signature from the neutron star binary merger.
The latter referring to the speed of gravitational waves. The speed of the force of gravity is the instantaneous part. For example if the speed of the force of gravity traveled at the speed of light, the earth/moon system would be attracted to the sun at its position when it emitted the force about 8 minutes previosly and our orbit would quickly degrade and we would fall into the sun.


Trivially false.

Aug 15, 2019
Many people think a supermassive galactic core is inevitably a picky-eater and it ends up blowing away all the fuel used to form new stars and maybe that's supposed to tip the scale toward gravitational entropy, to be the end of the idea that gravity works against entropy. This is where a different model of galactic-scale gravity matters, different gravity in the form of a static galaxy-enveloping ripples could provide an unappreciated barrier against fuel loss. If gravity has filament-like spin-focus within it then one galaxy's polar-ejected fuel loss is another galaxy's polar-absorbed fuel gain.

There is supposedly an issue involving Helium depletion that could get blamed on gravity but I don't know that it means much in terms of free energy and entropy.


Aug 16, 2019
I hope this guys is right. I don't like the Dark Matter hypothesis, even though apparently it predicts a lot of stuff, i feel its a cop out due to lack of anything better.


Most studies so far that have looked at this show that it doesn't match observation. Don't be putting your mortgage on it!

https://en.wikipe..._gravity


Oh I am not trust me :P But I feel black matter has a lot of similarities with religion: We can't prove it's there but we can use it to explain a lot of things.

Does this mean we need to stop investigating it? No of course not. But we should not stop looking for alternatives either.

Aug 16, 2019
Oh I am not trust me :P But I feel black matter has a lot of similarities with religion: We can't prove it's there but we can use it to explain a lot of things.

Does this mean we need to stop investigating it? No of course not. But we should not stop looking for alternatives either.


It's not quite as 'religious' as you infer. If DM were to exist, scientists can make predictions based on its reality or otherwise. Observations so far confirm those predictions. The Bullet Cluster being the most widely known. There are other similar observations, as well. They can also perform simulations using various percentages of DM including none at all. This, for instance, has been done WRT the 'Cosmic Web'. Simulations only match reality with DM present in the currently predicted amount.
In addition, other explanations are looked at critically, and also tested against observation. Varieties of MOND, for instance, have been assessed. They are not doing very well!

Aug 16, 2019
i truly doubt these disagreements would even be occurring
if scientists had avoided using the terms Dark Matter, Black Hole & Big Bang that became popular memes

the looneyticks see "Dark", "Black", "Big Bang", triggering deep festering cowardice & bigotries in their tiny little minds

if Scientists could agree to more innocuous terms for the observed phenomena?

all the disease-bearing looneyticks infesting these comments would be off trolling for suckers on the religious forums

i know, i know, cutting into the loot collected by officially pious fakirs
but, i don't really care which breed of vermin afflict the flocks of the ignorant sheeple

"the only point of contention
between the wolf
& the shepard?
is which one of them
will get to eat the lamb!"

Aug 16, 2019
...maybe that's supposed to tip the scale toward gravitational entropy, to be the end of the idea that gravity works against entropy.
Let's hope so. Similar to the idea that wind works against pressure.

Aug 16, 2019
if the speed of the force of gravity traveled at the speed of light, the earth/moon system would be attracted to the sun at its position when it emitted the force about 8 minutes previosly and our orbit would quickly degrade and we would fall into the sun.
Trivially false.
Also trivially false - gravitational waves hold objects in orbit.

13 hours ago
He did an interview that seemed to imply gravity doesn't exist. It looked to me like high-brow electric universe theory. A lot of physicists seem to have a similar idea, one where objects cannot fall unless they can emit photons from their top-side to drive the process. I came up with a "proxy-gravity" theory where all gravity quanta would do is deform matter particles in such a way that the matter would have a bias in how it emitted photons that it would pick up from the random ambient. It doesn't seem realistic. Entropic gravity looks like another electric universe fail, but it's the first one to get a prize.

12 hours ago
People have problems with the truth that they can never put into words, EV is such a person about gravity.

12 hours ago
Also trivially false - gravitational waves hold objects in orbit.


Nope. The speed of gravity = c. As proven. The Sun disappears, Earth doesn't notice for 8 minutes. Either optically or gravitationally.

12 hours ago
""proxy-gravity" theory where all gravity quanta would do is deform matter particles in such a way that the matter would have a bias in how it emitted photons that it would pick up from the random ambient"

The idea was supposed to suggest a mechanism for gravitational light bending too. The main point was that the geometry of space, the background for other fields, was uniquely gravity-inspired, more specifically here by simple gravity quanta with simple effects.

Downrates around here can get downright perversely expressed at times, which I can only logically take as encouraging while appreciating it as a perverse form of discouragement.

11 hours ago
Something I read from time to time: "In general relativity, roughly speaking, a mass moving at a constant acceleration does not radiate."

That is like a stable circular orbit. It implies anything that doesn't move in a stable circular orbit radiates gravitational waves. You somehow become gravitationally invisible if you are in a stable circular orbit. Maybe this is from too far away. Maybe I missed something not going elliptical here, but I'm not seeing it. Maybe they are thinking of a spinning ring that doesn't produce frame-dragging?

What other kinds of movement actually could get expressed by gravitational waves? I mean they oscillate, you know. Maybe they have it mostly backwards or something else goofy Who knows.

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