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
all I know is that life would be b-—tch without it.
Basically what they are saying is that gravity is not a ‘force’ it’s an ‘effect’.............
Gravity is certainly no friend of my emergent phenomenon.
Even in the Garden of Eden which presumably was entropically regenerated from supernatural sources, something had to make sure that birds could fly but man and animals (and even that pesky serpent) remained firmly on the ground :-)
This should be obvious to anyone.
I wrote my thesis on this...1985....no big deal...
Then May the Force Be With You
Hope I posted it before someone else....
>> Basically what they are saying is that gravity is not a ‘force’ it’s an ‘effect’.............
No, if I’m reading it correctly, there’s a camp that believes it’s an “effect” (emergent, not a traditional force) and a camp that holds that it’s a traditional force.
Each side has (different sets of) equations that describe how gravity ought to behave, but actual measurements of neutron gravity agree with what the “traditional force”
equations.
Therefore gravity IS a traditional force and NOT an emergent “effect”.
me not understand :(
I am surprised that Verlinde didn’t look into this himself. Oopz.
>> all I know is that life would be b-—tch without it.
Maybe so, but a little less of it on Moving Day would be cool. :-)
We're stuck: that's all there is to it. Pretending we're not stuck by claiming gravity is an emergent phenomenon is not helpful.
Gravity has sentience? And will?
Hunh?
Title: Experiments Show Gravity Is Not an Emergent Phenomenon
From the article: Instead, it is an emergent phenomenon that merely looks like a traditional force.
Must be one of those spooky Quantum mechanical sentences.
yeah. it’ll be great when there’s an iPhone app for that.
You must have had an interesting Defense...
>> me not understand :(
Don’t sweat it. Just rearrange the jargon into meaningful English sentences and no one will ever know. You might even get offered a postgraduate research grant!
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