A controversial new gravity hypothesis has passed its first test

originally posted by: jappee
I had heard a theory i like as an explanation for gravity. It supposes that a mass in a vacuum, thus displacing the vacuum(state) creates an attraction to the mass which is displacing the vacuum... scale this to a planetary level, then wala.. gravity is perceived. I feel that all things/matter have an displacement effect upon the space around it..ie gravity

ETA: In effect we are "floating" on the surface of the vacuum, but stuck to the surface of the planetary mass displacing the vacuum.


Yeah i just proposed were all walking upside down...no joke

To put it simply..Gravity is a Vacuum force trying to suck us down but our atoms are too big and wont fit the hole in the vacuums hose.

a reply to: imjack
No need . I have known that gravity is mass acting on the space/time fabric since I was a kid. And I am old

its dangerous territory when the mind makes us see and derive anything it wants. science is on the verge of the outer limits, yet our progression as a civilization doesnt reflect that.

there will be another theory shortly.

originally posted by: pteridine
Note that the entire Dark Matter theory is just a fudge factor on a grand scale. It does fit data well because it has fudgeable terms within it. One only has to look at the historical calculated and measured speed of light to see how fudge factor terms work. There was about a 2 year delay in the calculated speed to match the measured speed.

All of this is done to predict events based on observations at hand and may have nothing to do with reality but is useful, just the same.

Your entire statement is false and shows a lack of understanding of physics and cosmology.

Just for anyone who is making bold statements about how dumb scientists are and their theories, the theories are interlocked with cosmological science and philosphy of time and space.

These things are not done simply to make predictions of observation, they are done to try and undetatand the nature of reality ontologically.

For those of you versed in quantum there is some strange stuff going on, it appears to relate to macro events as well. Such as superposition in visable objects. Entanglement etc.

a reply to: Vechthaan

Tongue in cheek opening statement is that two years at undergraduate level in some science (I assume physics) does not really make you a science in the job title sense, nor in the analytical sense either. Most undergraduates are taught about theories in a "This is a garden of theories and im going to show you which one has more evidence for" It starts to teach you problem solving and analytical thought BUT... from my experience (4 years combined undergrad with masters) + 4 years PhD + 7 years post-doctoral... id say that MOST students entering graduate school, are not amazing problem solvers and are still learning how to teach themselves and learn (which is what most of a PhD is about)

Throwing a reference to CERN in there, butters no parsnips

RIGHT so that being said, this points at the following
"That's why so many scientists, as do I, have problems with this theory."

SO many? how many exactly? Because I think if you actually was in the field of particle physics you would find there number to be either very small, or a hybrid. I say hybrid because true scientists are the first to admit that we don't know something, and not only that but be open to new ideas and theories.

Is it really nonsense to start thinking about exotic matter? Lets look at the times it was... and was successful... and the context around it in particle physics.

Wolfgang Pauli - 'Invented' a low mass (probably zero) particle with zero charge and extremely weak interaction probability meaning it would likely never be observed. He himself said it was not ideals and he had done a great crime to science by proposing such a thing.
In the end it was needed because beta-decay didnt appear to conserve energy and momentum. About 45 years later it was observed and about 90 years later we where running experiments looking for neutrinos coming from the sun and cosmic rays.

Charm Quark... and Top and Bottom(Beauty)
The standard model in the early 70s was very fresh, evidence from experiments in the 60s and early 70s had evidence that protons and neutrons where composite particles, leading to credence of quark theories. So back in the 70s science knew of 3 quarks... up down and strange. The theory predicted however that a certain class of strange quark decays should occur readily, but, where not observed in either accelerators where the quarks can be created, nor in experiments looking at high altitude cosmic rays showers.
It was proposed that when quarks interact or decay the outcome is determined by considering them as mixes of each other. This mixing actually predicted a suppression of those problematic decays that should of occurred very readily otherwise...and the outcome was a new quark... the Charm. This was predicted in the late 60s and evidence came mid way through the 70s with the production of the J/psi particle.
This theory goes further and becomes the CKM matrix that is in the standard model today, predicting both the bottom(beauty) and top quarks.

Dark Matter is a similar thing. People who say "Oh it is just a fudge factor in the theory" are ignorant of the theory they are talking about and what a fudge factor even is. They are also ignorant of just how wide ranging Dark Matter theories are. It is not a simple case of there being one theory, there are many.

What people fail to understand is exactly how these measurements and predictions work, rather just accepting the side notes and pretending they get it. A lot of observations go into the predictions of how much mass is present in external galaxies, which are checked and double checked. Dark matter is not a simple "Lets fudge the numbers here and boom done" The models lean on what we know about gravitation as it is, (some might say "Oh well thats the problem") but what the leading models do is say "If we have a heavy none interacting particle with a certain distribution, how does it evolve, how does it affect matter that we can see... in many ways the models are exactly the same as models we make to figure out real galaxy formation... so we are doing like for like analysis.

A quote from a prof i know "Verlinde has had excellent/non-trivial contributions in the field of mathematical physics. At the same time, he is the same physicist that made too much noise about 'entropic gravity', a theory that could be easily conceptually debunked by any undergraduate physicist (entropic phenomena, unlike gravity, cannot be time-reversed ). To my knowledge, MONDs have been "derived" from "string theory" in the past, but no-one made so much noise about it. I have yet to understand if he really derived anything novel and my opinion, based purely on his recent activity and not from a deep understanding of his paper, is that he didn't."

String theory is another little understood thing by the general masses too, people like to talk about it because it sounds so profound and deep... and yet... string theory predicts nothing that theories we already have don't already, and the side like predictions it does have tend to be wildly incorrect and often easily debunk-able using high school logic.

originally posted by: Gothmog

Could it be that like modern theory states about gravity flowing across the dimensions and universes , it is driven by dark energy ?
But for now
Dark matter/Dark energy = a singularity = we dont know wat the hell it is
Peace

That was my guess. String Theory suggests that the effects of gravity can extend across dimensions. So maybe the discrepancy we see in the gravitational lensing is due to gravitational force bleeding through from other dimensions.

originally posted by: luthier

originally posted by: pteridine
Note that the entire Dark Matter theory is just a fudge factor on a grand scale. It does fit data well because it has fudgeable terms within it. One only has to look at the historical calculated and measured speed of light to see how fudge factor terms work. There was about a 2 year delay in the calculated speed to match the measured speed.

All of this is done to predict events based on observations at hand and may have nothing to do with reality but is useful, just the same.

Your entire statement is false and shows a lack of understanding of physics and cosmology.

Just for anyone who is making bold statements about how dumb scientists are and their theories, the theories are interlocked with cosmological science and philosphy of time and space.

These things are not done simply to make predictions of observation, they are done to try and undetatand the nature of reality ontologically.

For those of you versed in quantum there is some strange stuff going on, it appears to relate to macro events as well. Such as superposition in visable objects. Entanglement etc.

Really? Just for anyone who can't read posts and has a knee-jerk reaction to other opinions, I never said scientists were dumb. I don't think theories are necessarily dumb. My entire statement is not false; the diddling of various parameters to make things fit can often show what parameters are important. Theories come and go, and dark matter is one of the latest to explain observation. Observation drives theory, does it not?
My statement about the measured velocity of light vs. the theory is true and is an example where observation drove theory. Dark Matter theory is driven by observation and is one version of how the universe behaves.
Science is used to understand with a goal of predicting how the universe operates and not as you suggest, to make predictions of observations.

Rethink your post.

originally posted by: ErosA433
A quote from a prof i know "Verlinde has had excellent/non-trivial contributions in the field of mathematical physics. At the same time, he is the same physicist that made too much noise about 'entropic gravity', a theory that could be easily conceptually debunked by any undergraduate physicist (entropic phenomena, unlike gravity, cannot be time-reversed ).

That seems like a weak or naive counterargument. It's a bit like saying "when atoms interact there is irreversible thermodynamics, so then Newton's proposed laws of mechanics, which are time-reversible, can't be right for objects in our universe. "

It's not uncommon to have truly microscopic physics and their symmetries look different when viewed or aggregated on collective levels and reformulated in terms of those variables.

originally posted by: pteridine

originally posted by: luthier

originally posted by: pteridine
Note that the entire Dark Matter theory is just a fudge factor on a grand scale. It does fit data well because it has fudgeable terms within it. One only has to look at the historical calculated and measured speed of light to see how fudge factor terms work. There was about a 2 year delay in the calculated speed to match the measured speed.

All of this is done to predict events based on observations at hand and may have nothing to do with reality but is useful, just the same.

Your entire statement is false and shows a lack of understanding of physics and cosmology.

Just for anyone who is making bold statements about how dumb scientists are and their theories, the theories are interlocked with cosmological science and philosphy of time and space.

These things are not done simply to make predictions of observation, they are done to try and undetatand the nature of reality ontologically.

For those of you versed in quantum there is some strange stuff going on, it appears to relate to macro events as well. Such as superposition in visable objects. Entanglement etc.

Really? Just for anyone who can't read posts and has a knee-jerk reaction to other opinions, I never said scientists were dumb. I don't think theories are necessarily dumb. My entire statement is not false; the diddling of various parameters to make things fit can often show what parameters are important. Theories come and go, and dark matter is one of the latest to explain observation. Observation drives theory, does it not?
My statement about the measured velocity of light vs. the theory is true and is an example where observation drove theory. Dark Matter theory is driven by observation and is one version of how the universe behaves.
Science is used to understand with a goal of predicting how the universe operates and not as you suggest, to make predictions of observations.

Rethink your post.

No need cosmology and philosphy are part of my degree. Dark matter is a 100 year old concept in astrophysics.

It's one that is accepted by a huge majority of a astrophysicists.

Your fudging number scenario is completely bs.

Ontology and cosmology are wrapped into these theories. The big bang, radiation pressure during the photon epoch etc are linked to dark matter and the cosmological model that has been around a very long time.


As far as observational dark matter you seem to be hinting at the lensing effect and being a "god in the gaps" scenario. This is not the case if that is your general point. Maybe I misread you, but you seem to imply these are whimsical ideas.

a reply to: 727Sky

I'd love to see what gravity really is. This is a necessary step.

originally posted by: luthier

originally posted by: pteridine

originally posted by: luthier

originally posted by: pteridine
Note that the entire Dark Matter theory is just a fudge factor on a grand scale. It does fit data well because it has fudgeable terms within it. One only has to look at the historical calculated and measured speed of light to see how fudge factor terms work. There was about a 2 year delay in the calculated speed to match the measured speed.

All of this is done to predict events based on observations at hand and may have nothing to do with reality but is useful, just the same.

Your entire statement is false and shows a lack of understanding of physics and cosmology.

Just for anyone who is making bold statements about how dumb scientists are and their theories, the theories are interlocked with cosmological science and philosphy of time and space.

These things are not done simply to make predictions of observation, they are done to try and undetatand the nature of reality ontologically.

For those of you versed in quantum there is some strange stuff going on, it appears to relate to macro events as well. Such as superposition in visable objects. Entanglement etc.

Really? Just for anyone who can't read posts and has a knee-jerk reaction to other opinions, I never said scientists were dumb. I don't think theories are necessarily dumb. My entire statement is not false; the diddling of various parameters to make things fit can often show what parameters are important. Theories come and go, and dark matter is one of the latest to explain observation. Observation drives theory, does it not?
My statement about the measured velocity of light vs. the theory is true and is an example where observation drove theory. Dark Matter theory is driven by observation and is one version of how the universe behaves.
Science is used to understand with a goal of predicting how the universe operates and not as you suggest, to make predictions of observations.

Rethink your post.

No need cosmology and philosphy are part of my degree. Dark matter is a 100 year old concept in astrophysics.

It's one that is accepted by a huge majority of a astrophysicists.

Your fudging number scenario is completely bs.

Ontology and cosmology are wrapped into these theories. The big bang, radiation pressure during the photon epoch etc are linked to dark matter and the cosmological model that has been around a very long time.


As far as observational dark matter you seem to be hinting at the lensing effect and being a "god in the gaps" scenario. This is not the case if that is your general point. Maybe I misread you, but you seem to imply these are whimsical ideas.

The fudge factor is not BS; it is used all the time. If I said "adjustable parameters," would you like that better? How many "adjustable parameters" does the standard model have. Five? Six?

I did not say anything about whimsy.

What happens to dark matter if the new theory of gravity is accepted?

a reply to: pteridine

The new theory of gravity is no where near being accepted. It would be a competitive theory for decades.

It depends. This theory of gravity doesn't explain why the universe is not smooth. It would have a lot of work to be put in to reconcile the current cosmological model to erase dark matter and why mass appears so off in terms of expansion.

originally posted by: luthier
a reply to: pteridine

The new theory of gravity is no where near being accepted. It would be a competitive theory for decades.

It depends. This theory of gravity doesn't explain why the universe is not smooth. It would have a lot of work to be put in to reconcile the current cosmological model to erase dark matter and why mass appears so off in terms of expansion.

In your opinion, can the new theory be used to tweak the standard theory or is it exclusive?

originally posted by: hubrisinxs
a reply to: 727Sky

I agree that the experiments show that the new theoretical model does its job predicting gravitational lensing, but the theory does not fix anything about gravity.

Erik's idea is in trouble regardless of the "time scale of relaxation". If his thermalization process occurs before the neutron hits the screen, the interference pattern will be destroyed. If the thermalization is slower, the interference pattern will be predicted at an unshifted place - because gravity only arises from the thermalization in his picture - which will contradict the observations that the phases and interference patterns are exactly as shifted as the equivalence principle predicts. There's no way to escape the contradiction simply because Erik's mechanism for gravity (which is a force that we observe) - a mechanism linked to entropy - causes some inevitable side-effects such as the loss of coherence (which are certainly not observed).

Link to source

and

[Sciencetist] argue that experiments with ultracold neutrons in the gravitational field of Earth disprove recent speculations on the entropic origin of gravitation.

Link to the actual experiment write-up

It seems Entropic gravity works to predict what it was designed to predict, but it fails to show anything other parts of gravity working correctly.

Anyway, sorry such a good topic turned to such dribble after only a few post, and yes as a mathematician I did pull my hair out a little.

Yes but the theory isn't trying to show the other parts, because they wouldn't BE a part of gravity, they would be a part of the causal effect for gravity.

What your saying here would be the equivalent of saying that the heat given by the friction of atoms doesn't explain what is moving said atoms. Of course it doesn't, it's only trying to explain the actual heat that's generated. It's up to another theory to explain what is moving the atoms.

Jaden

a reply to: pteridine

I would have to read the paper to be honest. It sounds like it's a tweaking of explaining some lensing. I haven't seen the observation of the bullet cluster but that would be of interest.

My post which was more open then just to you was that these theories are not whimsy. They are explanations for process we don't fully understand but are not flights of whimsy. Dark matter has been modeled fairly effectively. Neutrinos were dicovered.
I don't think this theory negates un explained mass and how fast the universe expanded, and isn't spread evenly.

Of coarse we could find things that completely change the understanding. My point is the working theories are not totally out there.

Virtual particles, dark energy, dark matter, antimatter, superposition, entanglement could be hinting at a muktiverse interaction. In my opinion from a philosphical point of view.


I can say for sure that if this is true the concept of reality is going to change drastically. Coded bits of information as building blocks sounds a lot like we are in a simulation.

Here is an ATS link on the subject...

www.abovetopsecret.com...

a reply to: 727Sky

"The dark matter model actually fits slightly better with the data than Verlinde’s prediction," Brouwer told New Scientist. "But then if you mathematically factor in the fact that Verlinde’s prediction doesn’t have any free parameters, whereas the dark matter prediction does, then you find Verlinde’s model is actually performing slightly better."

Having less parameters does not make it better, what ever model matches reality the closest is the best model, and that isn't a modified theory of gravity.

a reply to: Kashai

Thanks. Lots of links to papers. Whew have some reading to do. From the philosophical ontology perspective this is also fascinating and fits with some current models in other areas of science.

originally posted by: 727Sky
www.sciencealert.com...

"controversial" as the title says is one way of putting it. This quote comes straight from the article:

Verlinde's hypothesis might get rid of mysterious dark matter, but it doesn't match up with everything else we see in the Universe, either. String theorist Lubos Motl recently took down Verlinde's ideas a blog post, saying: "I wouldn’t okay this wrong piece of work as an undergraduate term paper."

If Motl's view was an exception that would be one thing, but numerous other experts have pointed out shortcomings in Verlinde's model.

originally posted by: hubrisinxs
a reply to: 727Sky

I agree that the experiments show that the new theoretical model does its job predicting gravitational lensing, but the theory does not fix anything about gravity.
...
It seems Entropic gravity works to predict what it was designed to predict, but it fails to show anything other parts of gravity working correctly.

As you mentioned, some rather glaring problems have been identified with the idea.

originally posted by: Vechthaan
The "dark" stands for that exact fact: it's unmeasurable. It doesn't leave a single trail in the electro-magnetic spectrum (whereas pretty much everything else does). This means that, by definition, dark matter does not emit/reflect light and does not emit/absorbe temperature or sound. For all intents and purposes, it does not exist in a measurable way. The only footprint dark matter leaves is the fact that galaxies seems to move away alot faster than we predicted.

This is completely wrong. Dark matter is measured indirectly. We even have maps of dark matter showing how much of it is located where based on these indirect measurements, so it's wrong to say it doesn't exist in any measurable way. And guess what? A lot of our measurements are indirect, even for things other than dark matter. Still, it would be nice to measure it directly or to find a better alternative explanation for the observations we have made.

The most hideously wrong part of that paragraph is the last sentence "The only footprint dark matter leaves is the fact that galaxies seems to move away alot faster than we predicted." That's dark energy, not dark matter, so you're telling us why you have problems with dark matter and you don't even know what observations let to dark matter being theorized. First we noted other galaxies were rotating so fast they should be flying apart if the only thing holding them together was the luminous matter, like stars. Then additional observations related to gravitational lensing also showed a lot more lensing taking place than could be explained by luminous matter. We can't see planets in other galaxies, so if there are other planets in other galaxies which we have every reason to believe there are, they probably account for some of the dark matter in a form called "baryonic dark matter" which definitely exists because you're standing on it. Yes a hypothetical planet like Earth in another galaxy is considered to be a form of baryonic dark matter. We have also made other observations that suggest that the dark matter is very unlikely to all be baryonic, and we don't really know what else it's composed of, though things like "WIMPS" or weakly interacting massive particles have been suggested as one possibility.

Alternate ideas like MOND were interesting but that didn't survive observations of the bullet cluster which claims to be a more direct measurement of dark matter. More about the bullet cluster observations and the implications here:

Dark Matter Observed: Most Direct Measurement of Dark Matter Allows Study of its Nature Apparently the researchers who tested Verlinde's idea didn't look at the bullet cluster, which probably should have been the first thing they looked at given the claim about it being the most direct measurement of dark matter yet.

a reply to: Arbitrageur

It may have some issues but that is very normal for a new theory. You can see I am pretty skeptical however, the problem of gravity understanding has not really gone away nor has the quantum world come to an understanding of its relationship in our macro world. Gravity could be a key in the puzzle. I have always wondered what entanglement and superposition, waveform probability are playing in the larger role and how they relate to gravity.

I have much less mathematical understanding of this but come more from the philsophical side of cosmology like time and space.