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Experiments Show Gravity Is Not an Emergent Phenomenon
MIT Technology Review ^ | 08/24/2011 | Staff

Posted on 08/24/2011 2:52:57 PM PDT by Red Badger

The way gravity effects quantum particles proves that it cannot be an emergent phenomenon, says physicist.

One of the most exciting ideas in modern physics is that gravity is not a traditional force, like electromagnetic or nuclear forces. Instead, it is an emergent phenomenon that merely looks like a traditional force.

This approach has been championed by Erik Verlinde at the University of Amsterdam who put forward the idea in 2010. He suggested that gravity is merely a manifestation of entropy in the Universe, which always increases according to the second law of thermodynamics. This causes matter distribute itself in a way that maximises entropy. And the effect of this redistribution looks like a force which we call gravity.

Much of the excitement over Verlinde's idea is that it provides a way to reconcile the contradictions between gravity, which works on a large scale, and quantum mechanics, which works on a tiny scale.

The key idea is that gravity is essentially a statistical effect. As long as each particle is influenced by a statistically large number of other particles, gravity emerges. That's why it's a large-scale phenomenon.

But today, Archil Kobakhidze at The University of Melbourne in Australia points to a serious problem with this approach. He naturally asks how gravity can influence quantum particles.

Kobakhidze argues that since each quantum particle must be described by a large number of other particles, this leads to a particular equation that describes the effect of gravity.

But here's the thing: the conventional view of gravity leads to a different equation.

In other words, the emergent and traditional views of gravity make different predictions about the gravitational force a quantum particle ought to experience. And that opens the way for an experimental test.

As it happens, physicists have been measuring the force of gravity on neutrons for ten yeas or so. And...wait for the drum roll... the results exactly match the predictions of traditional gravitational theory, says Kobakhidze.

"Experiments on gravitational bound states of neutrons unambiguously disprove the entropic origin of gravitation," he says.

That's an impressive piece of physics. It'll be interesting to see how Verlinde and his supporters respond.

Ref: arxiv.org/abs/1108.4161: Once More: Gravity Is Not An Entropic Force


TOPICS: Culture/Society; Technical
KEYWORDS: electrogravitics; force; gravity; physics; unifiedtheory
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To: jnsun
I do have a hard time believing that Gravity is a fundamental "traditional" force like the electromagnetic and nuclear forces, (so did Einstein)

He was the father of Quantum physics, even though he had to be dragged into it kicking and screaming at first. At first, he hated what he found. He didn't want to go there!

61 posted on 08/24/2011 3:49:34 PM PDT by concerned about politics ("Get thee behind me, Liberal")
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To: HiTech RedNeck

They Can! Except maybe for this.

http://www.freerepublic.com/focus/f-news/2768540/posts


62 posted on 08/24/2011 3:49:58 PM PDT by bigheadfred (But alas)
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To: the invisib1e hand
that's an implication of relativity, as opposed to a fact, correct?

No, it's a fact, as it has been observed literally billions of times (subatomic particles in an accelerator decay at a slower rate because of their high speed). They even flew atomic clocks around the globe and demonstrated that they had experienced less time passing. This particular phenomenon is about as ironclad as you get in an experimental science...

63 posted on 08/24/2011 3:50:08 PM PDT by Charles H. (The_r0nin) (Hwaet! Lar bith maest hord, sothlice!)
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To: HiTech RedNeck

Better than the suppository form. But hey, the O Boy will be out of office sooner or later.


64 posted on 08/24/2011 3:51:24 PM PDT by bigheadfred (But alas)
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To: Red Badger
"The way gravity effects quantum particles proves that it cannot be an emergent phenomenon, says physicist."

I believe they mean "affects".

65 posted on 08/24/2011 3:52:04 PM PDT by muir_redwoods (Somewhere in Kenya, a village is missing an idiot)
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To: concerned about politics
Both pilots experienced the same thing, therefore, human conscience says time can be manipulated. It is now a human reality, because it is believed.

I'm soooooo glad I stopped doing Acid in the 70's. I highly recommend your at least cutting back.

66 posted on 08/24/2011 3:53:19 PM PDT by FredZarguna (The power of the greatest rock band of all time--now a crack legal team. Coming to ABC this fall!)
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To: yarddog
I suppose a case could be made that magnetism is Love. The Bible says “God is love” and I think God is what holds the universe together.

Those who dabble on the far end of quantum physics, like Peter Wolf, claim love behaves like a photon, and multiplies itself. Hate, on the other hand, is anti-matter. It destroys, and becomes a black hole.

67 posted on 08/24/2011 3:53:21 PM PDT by concerned about politics ("Get thee behind me, Liberal")
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To: NorCoGOP

Hey, that’s my line!


68 posted on 08/24/2011 3:54:48 PM PDT by BenKenobi (Honkeys for Herman!)
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To: yarddog

Yep, an all purpose transporter would also be an all purpose object synthesizer, in principle. Driving it with sufficient information to synthesize that pretty date you wanted, rather than some rubber doll, might be tricky. Think petabytes or more....

John’s statement that God is love gets deep into the concept that Christians commonly call the trinity, the 3-part nature of a God that exists independently of the universe we know. There is a Son and a Father who can express love towards one another, and a Spirit who acts as a kind of messenger or intermediary, all rolled up into a single omnipotent deity (not the distinct multiple deities of pantheistic systems). Things that God creates (magnetism, etc.) can reflect or illlustrate this love, but they aren’t the same thing as that love.


69 posted on 08/24/2011 3:56:15 PM PDT by HiTech RedNeck (There's gonna be a Redneck Revolution! (See my freep page) [rednecks come in many colors])
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To: HiTech RedNeck

Enterprise has suffered long term effects from gravity. Trust me on this.


70 posted on 08/24/2011 3:57:46 PM PDT by Enterprise ("Those who can make you believe absurdities can make you commit atrocities." Voltaire)
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To: muir_redwoods

The affects have an effect.....


71 posted on 08/24/2011 3:57:52 PM PDT by Red Badger ("Treason doth never prosper.... What's the reason? Why if it prosper, none dare call it treason.")
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To: FredZarguna; Lazamataz
I'm soooooo glad I stopped doing Acid in the 70's. I highly recommend your at least cutting back.

This deserves your attention.

http://www.freerepublic.com/focus/f-bloggers/2768515/posts

72 posted on 08/24/2011 4:01:19 PM PDT by bigheadfred (But alas)
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To: HiTech RedNeck

I have had zero training in physics of any kind unless you call a college course in physical science as something close.

It is always sort of fun to daydream about light and time etc.

One can easily imagine that there is only one force making everything in the universe behave the way it does. that would obviously be God. One thing which does make me wonder is the Universe seems to be limitless just like an omnipotent God.


73 posted on 08/24/2011 4:02:11 PM PDT by yarddog
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To: Red Badger
As long as each particle is influenced by a statistically large number of other particles, gravity emerges.

I did'nt understand what gravity is. After reading this, I don't understand what "influenced" means. This article is muddying the waters and confusing the crap out of me. When I hit a nail with a hammer, I know I influenced the nail. Tell me exactly how these particles are influencing each other without actual contact, to create gravity.

74 posted on 08/24/2011 4:02:27 PM PDT by roadcat
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To: concerned about politics

That sounds awfully like ‘ether’.........


75 posted on 08/24/2011 4:02:41 PM PDT by Red Badger ("Treason doth never prosper.... What's the reason? Why if it prosper, none dare call it treason.")
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To: roadcat
Tell me exactly how these particles are influencing each other without actual contact, to create gravity.

An analogy: THIS thread on Free Republic...

76 posted on 08/24/2011 4:05:22 PM PDT by bigheadfred (But alas)
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To: Red Badger
The way gravity effects quantum particles proves that it cannot be an emergent phenomenon, says physicist.

Well, that would be cool if gravity actually effects quantum particles, but I think the writer was just illiterate.
77 posted on 08/24/2011 4:07:06 PM PDT by aruanan
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To: HiTech RedNeck
Whether a particle is a boson or fermion is simply a description of whether the state vector of a system composed of two such particles is symmetric or anti-symmetric when those particles are exchanged. So systems of multiple bosons remain bosons, as you say. But systems composed of multiple fermions can be bosons. The neutrons and protons in helium (4He) form a bosonic atom even though the particles individually are fermions (essentially, two fermionic systems, and just as -/- and +/+ = +, and -/+, +/- = - in algebraic multiplications, systems of even numbers of fermions can be bosons, and systems of mixed odd numbers of fermions and bosons can be fermions).

But fermions and bosons are not fundamental particles. This is just a description of the symmetry and statistical laws they obey. The particles we have are the quarks, leptons, and gauge bosons: photons, gluons, gravitons, W/Z particles. Combinations of quarks and combinations of leptons can be either bosons or fermions. The gauge particles -- which mediate energy or "force" are all bosons.

78 posted on 08/24/2011 4:09:06 PM PDT by FredZarguna (The power of the greatest rock band of all time--now a crack legal team. Coming to ABC this fall!)
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To: roadcat

Maybe the idea is that the universe is crammed with a network of... something. Something that science doesn’t know about and whose interactions with physical objects that science does know about does not have to conform to the known behavior of these physical objects. It wouldn’t be quite an “ether.” It wouldn’t need to be “supernatural” in the literal sense, but might be difficult to distinguish from such an entity.


79 posted on 08/24/2011 4:10:12 PM PDT by HiTech RedNeck (There's gonna be a Redneck Revolution! (See my freep page) [rednecks come in many colors])
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To: concerned about politics

“Why couldn’t the quantum, which is eveywhere and in everything, have enough mass, if evenly distributed, to hold things down? It would be sort of like living on a planet surrounded by undectable jello - an energy “aura”.”

What’s the difference between imagining that scenario and concocting a “luminiferous ether” or “dark matter” to make your theory work? Aren’t these just theoretical “fudge factors” used as a crutch to prop up an apparently flawed theory?

It seems like scientists sometimes try to reimagine reality to conform to their theory, rather than reimagine their theory to conform to reality.


80 posted on 08/24/2011 4:11:12 PM PDT by Boogieman
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