Scientist discovers how to lab test untestable string theory
28 replies, posted
[I]via: [/I]Physorg
[release]
[B](PhysOrg.com) -- Researchers describe how to carry out the first experimental test of string theory in a paper published tomorrow in [I]Physical Review Letters[/I].[/B]
String theory was originally developed to describe the fundamental particles and forces that make up our universe. The new research, led by a team from Imperial College London, describes the unexpected discovery that string theory also seems to predict the behaviour of entangled quantum particles. As this prediction can be tested in the laboratory, researchers can now test string theory.
Over the last 25 years, string theory has become physicists' favourite contender for the 'theory of everything', reconciling what we know about the incredibly small from particle physics with our understanding of the very large from our studies of [URL="http://www.physorg.com/tags/cosmology/"]cosmology[/URL]. Using the theory to predict how entangled quantum particles behave provides the first opportunity to test string theory by experiment.
"If experiments prove that our predictions about quantum entanglement are correct, this will demonstrate that string theory 'works' to predict the behaviour of entangled quantum systems," said Professor Mike Duff FRS, lead author of the study from the Department of Theoretical Physics at Imperial College London.
"This will not be proof that string theory is the right 'theory of everything' that is being sought by cosmologists and particle physicists. However, it will be very important to theoreticians because it will demonstrate whether or not string theory works, even if its application is in an unexpected and unrelated area of physics," added Professor Duff.
Professor Duff recalled sitting in a conference in Tasmania where a colleague was presenting the mathematical formulae that describe quantum entanglement: "I suddenly recognised his formulae as similar to some I had developed a few years earlier while using string theory to describe [URL="http://www.physorg.com/tags/black+holes/"]black holes[/URL]. When I returned to the UK I checked my notebooks and confirmed that the maths from these very different areas was indeed identical."
The discovery that string theory seems to make predictions about quantum entanglement is completely unexpected, but because quantum entanglement can be measured in the lab, it does mean that at last researchers can test predictions based on string theory. There is no obvious connection to explain why a theory that is being developed to describe the fundamental workings of our universe is useful for predicting the behaviour of entangled quantum systems. "This may be telling us something very deep about the world we live in, or it may be no more than a quirky coincidence", concluded Professor Duff. "Either way, it's useful."
[B]String theory[/B]
String theory, and its extension M-theory, are mathematical descriptions of the universe. They have been developed, over the last 25 years, by theoreticians seeking to reconcile the theories of general relativity and quantum mechanics. (The former describes the universe at the level of cosmology - the very large, while the latter describes the universe at the level of [URL="http://www.physorg.com/tags/particle+physics/"]particle physics[/URL] - the incredibly small). One of the major bugbears, especially of M-theory, is that it describes billions of different universes and ‘anything’ can be accommodated in one or other of the M-theory universes. Researchers have no way of testing which of the answers that string/M-theory gives us is ‘right’. Indeed, they all may be right and we live in one universe among an infinite number of universes. So far no one has been able to make a prediction, using string theory, that can be tested to see if it is correct or not.
[B]Qubit (quantum bit) entanglement[/B]
Under very precisely controlled conditions it is possible to entangle the properties of two [URL="http://www.physorg.com/tags/quantum+particles/"]quantum particles[/URL] (two quantum bits, or qubits), for example two photons. If you then measure the state of one of these entangled particles, you immediately affect the state of its partner. And this is true if the particles are close to one another or separated by enormous distance. Hence Einstein’s apposite description of quantum entanglement as ‘spooky action at a distance’. It is possible to entangle more than two qubits, but calculating how the particles are entangled with one another becomes increasingly complex as more particles are included.
Professor Duff and his colleagues realised that the mathematical description of the pattern of entanglement between three qubits resembles the mathematical description, in string theory, of a particular class of black holes. Thus, by combining their knowledge of two of the strangest phenomena in the universe, black holes and [URL="http://www.physorg.com/tags/quantum+entanglement/"]quantum entanglement[/URL], they realised they could use string theory to produce a prediction that could be tested. Using the [URL="http://www.physorg.com/tags/string+theory/"]string theory[/URL] mathematics that describes black holes, they predicted the pattern of entanglement that will occur when four qubits are entangled with one another. (The answer to this problem has not been calculated before.) Although it is technically difficult to do, the pattern of entanglement between four entangled qubits could be measured in the laboratory and the accuracy of this prediction tested[/release]
[URL="http://www.physorg.com/news202553083.html"]Source[/URL]
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[img]http://imgs.xkcd.com/comics/string_theory.png[/img]
[IMG]http://liberalvalues.files.wordpress.com/2010/03/sheldon.jpg[/IMG]
Told you so.
I used to think atoms were the smallest things possible.
Then neutrons, then quarks within them.
I bet that one day they will find something smaller than these so called "strings".
We have to go deeper.
[QUOTE=Sobotnik;24528359]We have to go [B]deeper[/B].[/QUOTE]
That, while the title of the thread contains Strings, is not very safe.
But yeah, never say "something is the smalles thing", its only the smalles we can detect.
[QUOTE=Sobotnik;24528359]I used to think atoms were the smallest things possible.
Then neutrons, then quarks within them.
I bet that one day they will find something smaller than these so called "strings".
We have to go deeper.[/QUOTE]
[IMG_THUMB]http://img547.imageshack.us/img547/3936/deeper.jpg[/IMG_THUMB]
[QUOTE=Eudoxia;24529229][IMG_THUMB]http://img547.imageshack.us/img547/3936/deeper.jpg[/IMG_THUMB][/QUOTE]
God damn you
[b]YEEEES!!![/b] Now let's see what happens.
[QUOTE=Sobotnik;24528359]I used to think atoms were the smallest things possible.
Then neutrons, then quarks within them.
I bet that one day they will find something smaller than these so called "strings".
We have to go deeper.[/QUOTE]
What if it just restarts after that?
Like inside the string is another universe.
[QUOTE=Extroll;24531690]What if it just restarts after that?
Like inside the string is another universe.[/QUOTE]
Well in that case your avatar pretty much explains what every scientist will do.
Too bad it is only a small section of string theory... Well at least some is better than none. I also find it kinda annoying they call it string "theory" when by definition it cannot be so (they can't test it as a whole).
[QUOTE=Extroll;24531690]What if it just restarts after that?
Like inside the string is another universe.[/QUOTE]
[img]http://eyeofgamers.files.wordpress.com/2007/09/800px-resonance_cascade_ayool.jpg[/img]
[QUOTE=Extroll;24531690]What if it just restarts after that?
Like inside the string is another universe.[/QUOTE]
Does that mean when we split an atom we destroy a universe?
[QUOTE=Tetracycline;24532239]Does that mean when we split an atom we destroy a universe?[/QUOTE]
Not one, but an infinite amount!
[QUOTE=Tetracycline;24532239]Does that mean when we split an atom we destroy a universe?[/QUOTE]
it would create 2 new universes for every instance of fission (which is caused by a neutron "bullet") that occurred, and it will happen a lot upon the detonation of a nuclear explosive device. when fission occurs, 2 neutrons are created, each of which can hit other atoms, causing them to split and form into 2 new universes, and therefore, causing the chain reaction. every fission that occurs also releases energy, which results in a massive explosion. it still all follows under the law of conservation, as the matter is just...divided.
tl;dr: atomic bombs create atoms.
It's funny, because the nuclear explosion could make the people think in the new universe that it's the Big Bang. Or am I wrong?
[QUOTE=Chris1337;24532706]It's funny, because the nuclear explosion could make the people think in the new universe that it's the Big Bang. Or am I wrong?[/QUOTE]
a more fitting term would be a "big bounce" because the original "universe" gets destroyed but in its destruction a new one is formed
[editline]09:34PM[/editline]
or more technically two
Almost a paradox, no?
[QUOTE=Sobotnik;24528359]
We have to go deeper.[/QUOTE]
[img]http://i31.tinypic.com/9bapt0.jpg[/img]
On topic, I don't really understand this, will someone explain.
[QUOTE=jwk94;24533767]
On topic, I don't really understand this, will someone explain.[/QUOTE]
it isnt really funny. but it helps if you saw inception.
[QUOTE=jwk94;24533767]
On topic, I don't really understand this, will someone explain.[/QUOTE]
Nothing to get. It's an image macro. Those things are generally unfunny.
Yay. Hopefully there will be more such tests thrown at it. If it passes all with flying colours (like the rest of QM) then maybe people can start to lay off it being a previously assumed unfalsifiable theory.
From the Brian Greene books I've read about string theory (AKA superstring theory/M-theory etc) it does seem a very compelling theory. Especially the way it came to be. It was leftover work from Einstein which started the theory in the first place, though it was previously used to try to reconcile Electro-Magnetism with general relativity using additional dimensions, but over time theorists realised that this was un-needed and the concept was left on the shelf. Then in the 70's scientists realised that it almost perfectly fit in to explain a reconcile gravity with general relativity and Quantum Mechanics. It's still being developed obviously, but it is still by far the most promising theory we have so far to unite everything. There is still no way to observe the strings directly however - to do as such would require a particle accelerator the size of the solar system, which is why it was deemed unfalsifiable. However, we [I]can [/I]indirectly observe and confirm predictions, such as the method suggested in the OP. Enough indirect evidence should suffice.
[QUOTE=Atchell;24534751]Nothing to get. It's an image macro. Those things are generally unfunny.[/QUOTE]
I think he means String Theory.
[QUOTE=jwk94;24533767][IMG]http://i31.tinypic.com/9bapt0.jpg[/IMG]
On topic, I don't really understand this, will someone explain.[/QUOTE]
The funniest part about this image is how lazy the photoshopping is. They didn't even bother shopping Xzibit in all the images
[QUOTE=Extroll;24531690]What if it just restarts after that?
Like inside the string is another universe.[/QUOTE]
[IMG]http://cubeupload.com/files/a4ca08jackiechanuniversesi.jpg[/IMG]
[QUOTE=Aurora93;24532627]it would create 2 new universes for every instance of fission[/QUOTE]
Wouldn't that be a flagrant violation of conservation of mass?
I'm a bass player. It is my undying goal to get so profoundly skilled at my instrument, that I can ply the universe's strings and warp reality with sweet music.
Smoke weed fuck bitches.
[QUOTE=DainBramageStudios;24546486]Wouldn't that be a flagrant violation of conservation of mass?[/QUOTE]
please reread
thank you
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