Fairly Simple Math Could Bridge Quantum Mechanics and General Relativity

The following article is taken from the email received from Scientific American magazine  {Noor Salik}

Some of the comments are interesting:

<–for example —>

Nonsense.  I suppose you don’t consider the transistor to be practical. The transistor could not have been invented without quantum mechanical solid state physics.

<——>

Actual article:

Fairly Simple Math Could Bridge Quantum Mechanics and General Relativity

A framework that relies on college-level mathematics could describe what happens to particles in so-called space time rips, gravity fluctuations such as those that occur during the birth of a black hole

By Eugenie Samuel Reich and Nature magazine

 

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Image: wylieconlon/Flickr

From Nature magazine.

Could an analysis based on relatively simple calculations point the way to reconciling the two most successful — and stubbornly distinct — branches of modern theoretical physics? Frank Wilczek and his collaborators hope so.

The task of aligning quantum mechanics, which deals with the behaviour of fundamental particles, with Einstein’s general theory of relativity, which describes gravity in terms of curved space-time, has proved an enormous challenge. One of the difficulties is that neither is adequate to describe what happens to particles when the space-time they occupy undergoes drastic changes — such as those thought to occur at the birth of a black hole. But in a paper posted to the arXiv preprint server on 15 October (A. D. Shapere et al. http://arxiv.org/abs/1210.3545; 2012), three theoretical physicists present a straightforward way for quantum particles to move smoothly from one kind of ‘topological space’ to a very different one.

The analysis does not model gravity explicitly, and so is not an attempt to formulate a theory of ‘quantum gravity’ that brings general relativity and quantum mechanics under one umbrella. Instead, the authors, including Nobel laureate Frank Wilczek of the Massachusetts Institute of Technology (MIT) in Cambridge, suggest that their work might provide a simplified framework for understanding the effects of gravity on quantum particles, as well as describing other situations in which the spaces that quantum particles move in can radically alter, such as in condensed-matter-physics experiments. “I’m pretty excited,” says Wilczek, “We have to see how far we can push it.”

The idea is attracting attention not only because of the scope of its possible applications, but because it is based on undergraduate-level mathematics. “Their paper starts with the most elementary framework,” says Brian Greene, a string theorist at Columbia University in New York. “It’s inspiring how far they can go with no fancy machinery.”

Wilczek and his co-authors set up a hypothetical system with a single quantum particle moving along a wire that abruptly splits into two. The stripped-down scenario is effectively the one-dimensional version of an encounter with ripped space-time, which occurs when the topology of a space changes radically. The theorists concentrate on what happens at the endpoints of the wire — setting the ‘boundary conditions’ for the before and after states of the quantum wave associated with the particle. They then show that the wave can evolve continuously without facing any disruptions as the boundary conditions shift from one geometry to the other, incompatible one. “You can smoothly follow this process,” says Al Shapere at the University of Kentucky in Lexington, a co-author on the paper, adding that, like a magician’s rings, the transformation is impossible to visualize, but does make mathematical sense.

The desire to escape the mathematical headaches caused by such transformations is one motivation for string theory, which allows smooth changes in the topology of space-time, says Greene. He suggests that the approach developed by Wilczek, Shapere and MIT undergraduate student Zhaoxi Xiong could be applied within string theory too.

Although Wilczek originally believed that the result was new, a 1995 paper by Aiyalam Balachandran of Syracuse University in New York proposed a similar strategy for describing changes in topology in quantum mechanics (A. P. Balachandranet al. Nucl. Phys. B 446, 299–314; 1995). Balachandran acknowledges that his work hasn’t hit the mainstream and says that he hopes Wilczek’s paper will prompt others to take a closer look. “Conventional approaches to this problem don’t get very far,” he says. “This opens up a new technique.”

 

A framework that relies on college-level mathematics could describe what happens to particles in so-called spacetime rips, gravity fluctuations such as those that occur during the birth of a black hole

By Eugenie Samuel Reich and Nature magazine

 

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The framework might also provide inspiration for experimentalists working on condensed matter. Rob Myers, a string theorist at the Perimeter Institute for Theoretical Physics in Waterloo, Canada, says that he expects it to be relevant to an area called quantum quenches, in which quantum systems evolve in isolation from the environment and are then kicked out of equilibrium by an action of the experimentalist. Condensed-matter physicists have developed several quantum systems — including cold-atom traps and superconducting circuits — that can be used to test this idea.

Although the authors lay out their solution in only one dimension, Myers expects that the approach will readily generalize to describe real experiments in three dimensions. But he cautions that the paper represents only a first step. “To really see the impact of this work, that will take a while,” he says.

This article is reproduced with permission from the magazine Nature. The article wasfirst published on October 30, 2012.

 

 

14 Comments

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  1. 1.    1. owlafaye08:57 PM 10/30/12

Bridging a 100 year old theory to a theory that has yielded nothing of practical value is a great way to continue wasting resources on roads that lead nowhere.

The protons were upset enough before quantum came along…leave them alone, admit you fell off the path somewhere, go back to a more promising idea and stop making fools of yourselves.

  1. 2.    2. robert schmidtin reply to owlafaye09:52 PM 10/30/12

Never have to wait long before some idiot comes along and says essentially that the world should take his word for it that the scientists are all wrong. Thanks for your contribution. You have made the world a much better place.

  1. 3.    3. slackerkeithin reply to owlafaye10:24 PM 10/30/12

@ owlafaye – You’re claiming quantum mechanics has “yielded nothing of practical value”? Man, you are a tool of the highest order.

  1. 4.    4. owlafayein reply to slackerkeith10:58 PM 10/30/12

Its a matter of your understanding of the word “practical”.

Physicists and their theories are at loggerheads with each other. You might say they always have been but in the past it led to great revelations and progress.

We are going nowhere towards the discovery of free energy solutions and travel amongst the stars.

Most physicists no longer have a “holy grail” relevant to humanity. Directed energy matters lay on the laboratory floor.

Leedskalnin, Tesla and other brilliant men were ignored by the rapaciousness of people like Westinghouse…once their research and goals are claimed and enhanced on by today’s scientists, we might just get somewhere.

Quantum mechanics only leads to answers that needed no question. They chase foolishness.

There is another scientific path to knowledge.

  1. 5.    5. Of NoImportance in reply to owlafaye11:55 PM 10/30/12

You speak as if, at present, every application of quantum mechanics is known – that there will never be a need to further study a certain science that works yet clashes with another.

And it’s not like the world is short on physicists. People can specialize; can pursue seemingly pointless goals for the purpose of finding out why – much like mathematics.

It is foolish to discard knowledge when it exists and no one knows why.

  1. 6.    6. negabladein reply to owlafaye12:13 AM 10/31/12

You haven’t actually said what that path is, other than something about upset protons which I’m assuming isn’t a literal description. If you have a self consistent framework with testable theories you should follow that path yourself and report on where it leads you. Or you could pay others to follow that path on your behalf. Your current approach is unlikely to succeed.

  1. 7.    7. And Then What?07:32 AM 10/31/12

Any theory that appears to constructs a mental bridge that allows us to understand why our current theories seem to be in conflict is worth exploring. To me it is a foregone  conclusion that the information we have at this point in time is just a glimpse of Reality. What lies in wait beneath and teases us with small bits of information about its true nature does not purposely hide from us. It simply is. We are curious, and want to know what drives everything, but unfortunately our vision of everything is not really everything, and so we interpret according to our perceptions. In a strange way we may be trying to go down the road with the cart before the horse. It may be that we will solve the true nature of the riddle by observing how the riddle affects its surroundings, but I suspect that any true understanding of how the riddle is constructed will only come once we understand the riddle itself. Mathematics may well describe the effects but in order for it to describe what produces the effects it must be “proven mathematically” that such a result is unique. This will always be open to attack based on the fact that “sample size” cannot be ignored as a determining factor with regard to the uniqueness of the result. Having said this, at our current stage of development, Mathematics and its underlying Logical framework would appear to be the best tools we have and may in fact lead us to our Eureka moment.

  1. 8.    8. bigbopperin reply to owlafaye09:36 AM 10/31/12

Nonsense.  I suppose you don’t consider the transistor to be practical. The transistor could not have been invented without quantum mechanical solid state physics.

  1. 9.    9. jahtez01:30 PM 10/31/12

owlafaye sez: “We are going nowhere towards the discovery of free energy solutions and travel amongst the stars”.

Think about that before you bother to respond.

  1. 10.  10. M Tuckerin reply to owlafaye05:13 PM 10/31/12

You have no idea of what you are talking about. It would be best for you to attempt to get some sort of basic notion of quantum mechanics before you decide it is a waste of resources. You might start with history. When you mentioned, “Bridging a 100 year old theory to a theory that has yielded nothing of practical value…” I was a bit perplexed but the rest of your rant made it clear that you consider general relativity to be the older theory but you are wrong. When general relativity gets to be 100 years old in a few more years I’m sure SA will have a nice article to commemorate the event. Perhaps you could investigate quantum mechanics to find out just what that theory has contributed to both physics and chemistry.