Posted on 03/27/2010 11:06:22 AM PDT by LibWhacker
The new role that quantum information plays in gravity sets the scene for a dramatic unification of ideas in physics
One of the hottest new ideas in physics is that gravity is an emergent phenomena; that it somehow arises from the complex interaction of simpler things.
A few month's ago, Erik Verlinde at the the University of Amsterdam put forward one such idea which has taken the world of physics by storm. Verlinde suggested that gravity is merely a manifestation of entropy in the Universe. His idea is based on the second law of thermodynamics, that entropy always increases over time. It suggests that differences in entropy between parts of the Universe generates a force that redistributes matter in a way that maximises entropy. This is the force we call gravity.
What's exciting about the approach is that it dramatically simplifies the theoretical scaffolding that supports modern physics. And while it has its limitations--for example, it generates Newton's laws of gravity rather than Einstein's--it has some advantages too, such as the ability to account for the magnitude of dark energy which conventional theories of gravity struggle with.
But perhaps the most powerful idea to emerge from Verlinde's approach is that gravity is essentially a phenomenon of information.
Today, this idea gets a useful boost from Jae-Weon Lee at Jungwon University in South Korea and a couple of buddies. They use the idea of quantum information to derive a theory of gravity and they do it taking a slightly different tack to Verlinde.
At the heart of their idea is the tricky question of what happens to information when it enters a black hole. Physicists have puzzled over this for decades with little consensus. But one thing they agree on is Landauer's principle: that erasing a bit of quantum information always increases the entropy of the Universe by a certain small amount and requires a specific amount of energy.
Jae-Weon and co assume that this erasure process must occur at the black hole horizon. And if so, spacetime must organise itself in a way that maximises entropy at these horizons. In other words, it generates a gravity-like force.
That's intriguing for several reasons. First, Jae-Weon and co assume the existence of spacetime and its geometry and simply ask what form it must take if information is being erased at horizons in this way.
It also relates gravity to quantum information for the first time. Over recent years many results in quantum mechanics have pointed to the increasingly important role that information appears to play in the Universe.
Some physicists are convinced that the properties of information do not come from the behaviour of information carriers such as photons and electrons but the other way round. They think that information itself is the ghostly bedrock on which our universe is built.
Gravity has always been a fly in this ointment. But the growing realisation that information plays a fundamental role here too, could open the way to the kind of unification between the quantum mechanics and relativity that physicists have dreamed of.
Ref: arxiv.org/abs/1001.5445: Gravity from Quantum Information
You could look at it another way and say that relativity is the obstacle to the theory of everything. It would be more accurate to say the relativity and quantum mechanics contradict each other. The theory of everything will have to harmonize both theories in some way.
Personally I think they are both wrong but that quantum theory is more wrong than relativity. Both of them are getting pretty long in the tooth as well. Quantum theory is about 80 or so and relativity is more than 100. It would be nice to see a physicist consider some alternative theories instead of just try to find more evidence that can be interpreted as supporting the old ones.
Yes, quantum mechanics is counterintuitive, but then for subatomic particles it gives correct results and relativity gives incorrect results.
String theory may be the way forward, but there is no consensus yet. Besides, strings would be so small, there is no way to verify that they actually exist. Still it's very interesting.
An object moving through space at a constant velocity has no acceleration. Therefore no force is acting upon it. To change its velocity, there must be an acceleration. To get that acceleration, a force must act upon the moving object.
The velocity at which the universe is expanding is increasing. That means there is an increase in acceleration. That increase can only come about due to a force.
Thank you. That's probably the most clear and concise explanation I've seen on the subject. You must be a good teacher, 'cause I don't feel so dumb as reading the rest of these posts. Wasn't it Lord Kelvin who said physics should be clear enough to be explained to a barmaid, or some such thing?
I’m not sure that it really gives “correct” results. It seems to hold together mathematically, but no one has actually tested the theory. The only way you can really test the theory is to recognize that the fundamental staple is a probability. No one has ever tested to see if the actual probabilities are the same as the predicted probabilities. The crown achievement of quantum theory is Feynman’s calculation of the value of the electron charge, based on probabilities. If you look up the value of an electron charge, you will see it calculated to the 23rd decimal place, but no one has actually measured it that far because it’s simply impossible. Everyone assumes that Feynman’s calculation is correct, so they use the theoretical value. And you have physicists claiming that the theory is correct because it gives you a value of the charge of an electron precise to the 23rd decimal place. What they really mean, though, is that you can predict the charge of an electron to the 23rd decimal place. Whether the prediction is correct, though, is another matter. And no one knows that.
I don’t think string theory makes much sense, either. Probably the best place to start would be with Special Relativity. Einstein’s theory is the closest I think to the mother load, but it’s got a problem. It’s not a complete theory of time. You can compare your own time regime to the time regime prevailing in another frame of reference, but there is nothing in the theory that explains the rate at which time passes in your own frame of reference. In order to get at the bottom line, you need a theory of time, and they don’t have that yet. The nature of time is still a mystery. Once you have the answer to that, you can adjust the Special Theory to take that into consideration, and then a new version of quantum theory will fall right into place.
“String theory may be the way forward, but there is no consensus yet.”
I started to respond to another poster, but saw this and realized you have wonderfully condensed all that is wrong with all that is called science today.
SCIENCE IS NOT DONE MY CONSENSUS.
Every new discovery in science always comes from that rare individual genius who contradicts the consensus.
Global warming and evolution are “sciences” done by “consensus;” which is why they are not science.
(Don’t get funny ideas. I do not believe in God or creation.)
Hank
Erik and I were discussing this last July at Duggan's Pub. Looks like he finally believed me............FWIW, he's a lousy pool player.
There's no need to shout. An individual can make any theory he chooses. But it only has currency when a consensus is reached. That's the value of a consensus.
Every new discovery in science always comes from that rare individual genius who contradicts the consensus.
Then can you name me that rare individual genius who came up with string theory?
All the rules and formulas for quantum mechanics were laid down by 1928. Since then it has been used to make the most precise numerical predictions in the history of science.
I don’t think string theory makes much sense, either.
Nothing in the theory says you have to think it makes sense.
Probably the best place to start would be with Special Relativity.
OK, good luck with your theory.
Great quote. Whoever said, I think he was right.
“There’s no need to shout. An individual can make any theory he chooses. But it only has currency when a consensus is reached. That’s the value of a consensus.”
Apperently there is a need to shout since so many people are deaf to the truth. I thought some people might have finally tumbled to it when the “global warming” fraud, driven entirely by the “consensus” idea of “peer review” was revealed for what it is.
A hypothesis only becomes a theory when it has been verified by reality, not how many people agree with it. Every advance in science has been against the accepted “consensus” view, from anesthesia to “heavier then air human flight.” It is not the opinion of any number of people that establishes any truth, it is reality itself, and whatever is an incorrect description of any aspect of reality, it is not true, no matter how many people agree with it.
Consensus is a great method for putting over lies, it is worse than useless in science.
Hank
There was never a consensus among climatologists that global warming is good theory. Newspapers and some politicians decided it was fact. And a vocal group of climatologists got a lot of money for writing reports that supported the theory.
A hypothesis only becomes a theory when it has been verified by reality, not how many people agree with it.
Popular opinion and the newspapers may think that a theory is verified. But that is not the way science works. A theory is never verified. All you can do is test the theory by taking measurements. If the measurements come within some tolerance of the predicted results, then you can say the measurements support the theory. But no theory is ever verified. It you ever wrote up a report in a physics lab in college and said your experiment verified a theory, you would get an F.
Ok, you made me look:
“If you can’t explain your physics to a barmaid it is probably not very good physics.”
—As quoted in Journal of Advertising Research (March-April 1998)
Variant: “A theory that you can’t explain to a bartender is probably no damn good.”
—As quoted in The Language of God (2006) by Francis Collins, p.60
I also particularly liked this one:
“All science is either physics or stamp collecting.”
—As quoted in Rutherford at Manchester (1962) by J. B. Birks
Unsourced variant:
“That which is not measurable is not science. That which is not physics is stamp collecting.”
“Physics is the only real science. The rest are just stamp collecting.”
—(Unsourced)
“That which is not measurable is not science.” is also attributed to Lord Kelvin
Guy had a talent for a well turned phrase!
http://beyond-information.blogspot.com/
I've discovered two things. One is the direct representation of existence. The other is the universal representation of thought.
The direct representation of existence is literally the ontology of existence. It is a new basis for the representation of formal systems that is both consistent and complete. It will provide a new foundation for logic and the mathematics required to address RQFT effectively. It is the basis for the unification of physics. It will allow us to develop a complete and consistent description of existence rapidly and efficiently.
It offers the possibility of allowing us to manipulate the structure of time, space, and matter directly. Using this system, we will be able to directly simulate all the relations and interactions required to learn how to do so.
The universal representation of thought is the ontology of thought. It is the basis for the neural representation of thought. It can be used to create computers that understand the meaning of information directly, and manipulate concepts and abstractions at the level current computers manipulate bits. Its representation is combinatorically more efficient in time and space than that of systems based on information.
I am currently in the middle of developing a software program that combines both the direct representation of existence and the universal representation of thought in a single computer program. With it, we will be able to simulate creation of the universe, including the creation of space, time, matter, and the construction of the laws of physics. Using the universal representation side of the system, we will be able to create true thinking computers. It will allow people to interact with their computers simply by writing or talking to them in natural language. The representation itself is extremely well suited for distributed use. I could release it to the world as a peer to peer application and create the worlds first planetary scale AI. In effect, it would allow everybody on the planet to interact with each other and contribute ideas as if they all shared part of the same brain. However, the system itself can also use those ideas, think about them, integrate them, and extend them. It will allow us to integrate and seamlessly refine and extend the knowledge of humanity within a single consistent, complete domain of representation. Furthermore, we won't have to do any work to integrate the knowledge. The representation does it all automatically, in exactly the same way our thoughts integrate information automatically within our brains.
Among other things, the direct representation of existence has allowed me to derive a consistent hypothesis for:
1) The cause of the quantization of energy 2) The first cause of symmetry. 3) What spacetime is and how it is created and represented 4) The cause of the big bang and the expansion of the universe 5) The cause of the zero point field 6) The cause of gamma ray bursts 7) The cause of zitterbewegung 8) The cause of mass 9) The representation of spin 10) The cause of gravity 11) The representation of quarks 12) The basic representation of subatomic particles.
I have been able to derive all of this and more directly from the representation of the direct ontology of existence qualitatively, but to model it quantitatively I need to finish my simulator. The field interactions are context dependent, too dynamic and too complex to work out by hand using current mathematics.
I've got a lot of work ahead of me to get this ready for publication. I also have about a year of work to do to finish my simulator. Looks like its going to be an exciting year.
“most precise numerical predictions in the history of science.”
Exactly. Just precise predictions. But where is the experiment proving that they are accurate?
“A theory is never verified.”
There was a hypothesis that heavier than air human flight was possible. At the same time the Wright Brothers were flying, the “academic” scientific community were writing prestigious papers proving it was not possible. Perhaps you are not convinced the “hypothesis” that heavier-than-air human flight is possible has been verified.
By the way, a “theory” is a hypothesis that has been proven. So long as it is not “verified” it is only a hypothesis, not a theory.
Perhaps you believe the hypothesis that communications signals could be transmitted to and from Earth by a relay station launched into orbit around the earth’s equator at a distance of about 22,300 miles, has not been verified. At that altitude, the “satellite” would maintain a stationary position over the earth, by maintaining an orbital speed of approximately 6000 miles per hour. But of course that hypothesis has never been verified either.
And of course the hypothesis that signals could be transmitted through the atmosphere electromagnetically has never been verified. Nor has the hypothesis that anisthesia could be used to perform painless surgery.
But for those who prefer to live in a world of total skepticism, nothing can ever be verified or proved. What a horrible way to live.
Hank
A theory is never proven in the sciences. Inductive reasoning is not a proof.
If you want proof you have to go to mathematics. Deductive reasoning provides a proof.
There is no such thing as an accurate measurement in the sciences. That's why in an experiment you take many measurements and then calculate an average.
Yes, but there is little or no effort among quantum physicists to determine whether these fantastically precise predictions actually mirror reality. I don’t see how you can call it a settled question that quantum physics is correct until someone actually does such a study. If the actual experimental parameters only loosely approximate what they claim are highly precise theoretical predictions, then one would have to wonder whether they’ve got it right.
No, they don't loosely approximate. The experimental results are exceptionally close to the theoretical predictions. That's why it's a good theory.
As for getting it right, it's the best theory yet devised to describe subatomic particles. If you apply relativity theory to subatomic particles, you get bad results.
And that's the contradiction in physics. We need one theory (relativity) for large objects, and a different theory (quantum mechanics) for small objects.
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