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How Curved Spacetime Can Be Created In a Quantum Optics Lab
KentuckyFC writes: One way to explore the link between quantum mechanics and general relativity is to study the physics that occurs on a small scale in highly curved spacetimes. However, these conditions only occur in the most extreme environments such as at the edge of black holes or in the instants after the Big Bang. But now one physicist has described how it is possible to create curved spacetime in an ordinary quantum optics lab.
The idea is based on optical lattices, which form when a pair of lasers interfere to create an eggbox-like interference pattern. When ultracold atoms are dropped into the lattice, they become trapped like ping pong balls in an eggbox. This optical trapping technique is common in labs all over the world. However, the ultracold atoms do not stay at a fixed location in the lattice because they can tunnel from one location to another. This tunneling is a form of movement through the lattice and can be controlled by changing the laser parameters to make tunneling easier or more difficult.
Now, a physicist has shown that on a large scale, the tunneling motion of atoms through the lattice is mathematically equivalent to the motion of atoms in a quantum field in a flat spacetime. And that means it is possible to create a formal analogue of a curved spacetime by changing the laser parameters across the lattice. Varying the laser parameters over time even simulates the behavior of gravitational waves. Creating this kind of curved spacetime in the lab won't reveal any new physics but it will allow researchers to study the behavior of existing laws under these conditions for the first time. That's not been possible even in theory because the equations that describe these behaviors are so complex that they can only be solved in the simplest circumstances.
The idea is based on optical lattices, which form when a pair of lasers interfere to create an eggbox-like interference pattern. When ultracold atoms are dropped into the lattice, they become trapped like ping pong balls in an eggbox. This optical trapping technique is common in labs all over the world. However, the ultracold atoms do not stay at a fixed location in the lattice because they can tunnel from one location to another. This tunneling is a form of movement through the lattice and can be controlled by changing the laser parameters to make tunneling easier or more difficult.
Now, a physicist has shown that on a large scale, the tunneling motion of atoms through the lattice is mathematically equivalent to the motion of atoms in a quantum field in a flat spacetime. And that means it is possible to create a formal analogue of a curved spacetime by changing the laser parameters across the lattice. Varying the laser parameters over time even simulates the behavior of gravitational waves. Creating this kind of curved spacetime in the lab won't reveal any new physics but it will allow researchers to study the behavior of existing laws under these conditions for the first time. That's not been possible even in theory because the equations that describe these behaviors are so complex that they can only be solved in the simplest circumstances.
It's not meant to be brain hurting territory.
It's like how zero gravity isn't possible on earth, but if you take a plane, and fly it in a parabolic curve matching G, the inside operates a lot like zero gravity.
This is like that, but for arbitrarily curved space-time, instead of zero G.
Stop making my brain hurt!
I think that's the point. It's too complex to model but if you have a playground that you can
play with you can explore interactions without having to do a ton of math.
Most people can't grasp certain complex stuff. Even something as simple as combining
green light and red light to make yellow confuses people as it goes against their grade school intuition.
Allow people to get a chance to play with it in a lab and then it just clicks.
That's not what quantum tunneling is. Tunneling has to do with the phase-state of particles, and how it implicates their ability to cross force barriers that should reverse them under classical understanding.
It's a bit like if your car blinked into and out of existence every couple seconds, you could sometimes drive through a brick wall.
Since all mass curves spacetime I can curve spacetime simply by existing and being a bit overweight. Its just too bad that I'll have to wait until 2015 for the nobel prize!
Argh, it's like I've been sucked into Star Trek, and everyone just uses science terms for whatever, as if they're all related.
No. Not the zero point field. Not at all.
I've calculated it's precisely the day after you die, which is also when immortality is invented. Tough break, duder.
Now, a physicist has shown that on a large scale, the tunneling motion of atoms through the lattice is mathematically equivalent to the motion of atoms in a quantum field in a flat spacetime.
mathematically equivalent ?
So they haven't created curved spacetime in a Quantum Optics Lab. They have done something that is a model of how they think curved space time would behave.
Related news: How faster-than-light travel can be created in a reflected sunlight spot.
ordinary quantum optics lab
Something about the wording in that phrase gives me the urge to search Instructables for a how-to...
An enigma, wrapped in a riddle, shrouded in bacon and cheese
Are they talking about general relativity equations?
That's included, but I think the article and summary are actually getting it right for once. The equations in question are ones that reconcile GR with Quantum Mechanics, and that, in general, means variations on various String or Brane Theories, and quite possibly specifically Supersymmetry, if that's not being completly discarded by the researchers just because CERN is finding preliminary evidence that the simplest and lowest energy Supersymmetry model doesn't work. It's possible some alternatives to those models can also be tested and refined or dismissed, but either way, we really are looking at math where complexity increases result time very, very rapidly. Here's a link for an example of some math used for both Supersymmetry and more general String Theory calculations - If you look at the section specifically about "Stringy theories" calculations, there's a good example of a formula that's obviously, by simple inspection, prone to grow very quickly with added terms for more complex situations, and there's some other quite good examples in the lead up to that section.
Lie superalgebras of string theories
http://arxiv.org/abs/hep-th/97...
(Note: Paper is 22 pages in PDF, and is NOT behind a paywall).
Who is John Cabal?
I'd like to see people try to keep pedantry off of slashdot!
Fundamental to general relativity is the principle of equivalence, which equates gravity in one reference frame to uniform acceleration in another one. It's why old-school space stations are big wheels -- they create gravity without using mass, by spinning. In the right coordinate system - one that rotates relative to the lab - the ultracentrifuge in a biochemistry lab creates a highly curved spacetime equivalent to 6 times the gravity at the surface of a white dwarf. (2 million g vs 350,000 g).
Curved optical spacetime analogs are not so special, after all, then. But they don't have the issues with angular momentum, nonuniformity that centrifugal gravity has, so they could make answering certain questions easier.
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