Mekt-Hakkikt
Mpanty's bane
Didn't you play C&C- Red Alert? Killing Hitler wouldn't lead to better 1940s. 
Has space been made too small?
- Thread starter Treguard
- Start date
Unforgiven
Spaceman
Scientists have indeed create what some call a transporter, but it can only transport photon's, not even molecules.
The idea is based on the Einstein-Podolsky-Rosen experiment. This experiment was created by those three to prove that Quantum Mechanics is wrong, and goes as follows (greatly simplified): If you create two particles from the same source with the same momentum and impulse, you know that if you find particle A 100 meter to the right of the source you'll find B 100 meter to the left, this is trivial highschool classic mechanics. According to Quantum Mechanics, the measurement itself determines the outcome of the measurement (note: only on molecular and smaller scales). The moment you measure the position of the A particle, you decide where it is. Before that, the particle has no position, but is in a 'super-state' consisting of the chance you'll find it at any position, as indicated by the Schrodinger equation.
Now, what Einstein, Podolsky and Rosen claimed was that this cannot be true, because determining the position of A would then also determine the position of B at the same time. A is in a super-state and B as well, then you measure the position of A taking it 'out of the superstate' and find an actual position. According to the Schrodinger Equation, there's is a chance that B will also be there. But because A and B were created with above conditions, it turns out that B is at that exact opposite position, which means that when you measured A and replaced it's superstate for a position you also replaced B's superstate for a position. So measuring the position of A determines the position of B. This would warrant some form of instant (=faster than light) communication between the two particles, which can't be according to the theory of general relativity, so Quantum Mechanics must be wrong!
However, it turned out that this is what actually happens. We don't yet know how or why, but it does. The 'communication channel' is sometimes referred to as the EPR-bridge.
Now it is possible by send two photons through some crystalline structure (forgotten exactly what) to connect them in such a way that any change in the state of photon A will result in will result in photon B taking the exact opposite state, via the EPR-bridge, regardless of how far they are apart. Such a pair of photons is called an EPR-pair. Now some technique is used which has photon A take on the exact opposite state of a third photon C, which comes down to measuring the state of C using A which causes A to take on this opposite state. This has, via the EPR-bridge, the effect of changing B. It also has the side-effect due to measurement changing the state of what was measured that C loses it's old state, it's new state is undefined.
The end-result is that photon B is now in every way possible (except position of course
) identical to what C was, and C itself was lost. In effect, C was transported to the location of B.One of the things scientists are looking into is creating EPR-pairs of larger paricles, like electrons, and maybe even of more than one particle at the same time, like a complete atom or even molecule.
Probably the best story about the problems inherent in time travel is the X-Files episode where the guy comes back in time to prevent some inventions that will allow time travel and ends up killing his younger self (intentionally).
If time travel were invented, and if people used it, history would become fluid. There would be no solid base on which time could exist, and what was true one second might not be true the next simply because someone had gone back in time and changed something.
Personally, I think my favorite thing I've heard about time travel is this (heard it from a friend): If you could figure out how to travel through time, the first thing you would do is go back in time and change things so that you ruled the world, and the second is that you would change things so that time travel was never invented (so no one could take your rulership away from you).
If time travel were invented, and if people used it, history would become fluid. There would be no solid base on which time could exist, and what was true one second might not be true the next simply because someone had gone back in time and changed something.
Personally, I think my favorite thing I've heard about time travel is this (heard it from a friend): If you could figure out how to travel through time, the first thing you would do is go back in time and change things so that you ruled the world, and the second is that you would change things so that time travel was never invented (so no one could take your rulership away from you).
Well as for the time travel issues...
Multiple universes help solve time paradoxes. For example
If a man goes back in time and kills his grandfather before his father was born, then his father never existed and neither did he, so he was never born and could of never gone back in time to kill his grandfather and prevent his own birth.
Well multiple universes, instead of a single timeline, solves this problem. The answer would be he starts another universe, where his father, and him never existed. Of course, he could stay in that universe and watch what happens.
The only warning with this idea is, if you go screwing around with timelines, don't be shocked to see some time traveler coming after you at some point
Also here is another good debate topic. If time is possible, where are the time travelers? I believe Einstein believed that nature may not let time travel into the past beyond the point when the first time traveling device was created. Interesting theory. What do you all think?
Multiple universes help solve time paradoxes. For example
If a man goes back in time and kills his grandfather before his father was born, then his father never existed and neither did he, so he was never born and could of never gone back in time to kill his grandfather and prevent his own birth.
Well multiple universes, instead of a single timeline, solves this problem. The answer would be he starts another universe, where his father, and him never existed. Of course, he could stay in that universe and watch what happens.
The only warning with this idea is, if you go screwing around with timelines, don't be shocked to see some time traveler coming after you at some point
Also here is another good debate topic. If time is possible, where are the time travelers? I believe Einstein believed that nature may not let time travel into the past beyond the point when the first time traveling device was created. Interesting theory. What do you all think?
Lord QDaan
Spaceman
Unforgiven: I'll be honest, I don't know too much about these things, but it sounds vaguely like this article on quantum entanglement I read a little while ago in the December issue of Scientific American. It speaks of the recent entanglement of two golfball-sized clouds of cesium containing trillions of atoms.
Either you have outdated info, or I'm confused again.
Either you have outdated info, or I'm confused again.
actually according to everything that I have heard Time travel back in time is quite impossible/improbable, since the only two theoretical ways of doing it would be either to accelate 1 side of a wormhole to near C, so that it stays near the same time as when it was opened, and then let the other side stay normal so that you would travel back to right when the wormhole was opened/accelerated, the problem is that when it is time to slow down the worm hole, the damned thing would explode.
the other theory involves creating a very very very rapidly rotating cylinder of extreme mass, several orders of magnitude more mass than Sol has. As a ship/person/object moved right along the outside of this cylinder towards the center of it's length it would be warped back in time, but still ends back to a time AFTER the cylinder was created just before the object entered into the gravitational effects of the cylinder.
This means that the Cylinder must already be built in order for time travelers to come to us, and since FTL isn't possible, it would have to be within a reletivly close range to our solar system in which case earth would be rotating around it rather than Sol
Unforgiven
Spaceman
My info might be a little outdated, it is possible that they've done it with something larger than a photon by now, but I'm not sure.
You understood it wrong. The EPR-experiment was designed to prove Quantum Mechanics wrong, because that communications channel couldn't exist. Since it turns out it actually does exist, QM is right, and the EPR-experiment failed.
Einstein did that a lot, trying to come up with (thought) experiments to prove QM wrong. But all those experiments did was prove that QM was actually right.
Poor Einstein, he just didn't want to believe that Quantum Mechanics could be correct.
"I refuse to believe God is playing dice with the Universe." - Einstein
Indeed I did. I seem to be doing that a lot around here lately. Must be slippin' in my old age. I've been posting late at night lately, after I'm done studying, so mot things I sat don't seem to make sense the day after. Say, you don't by any chance know where they conducted this experiment, do you?
Actually, Napolean, there are several methods that have been proposed. The theory of using an infinitely long cylinder is one method. The problem is that the cylinder needs to be infinite in length. Negative Energy created by way of the "Cassimir Effect", Colliding Cosmic Strings, and several other methods have also been proposed. The truth is that we know to little about time in order to truly understnad it. Time travel will probably be impossible untill we reach the point where we can manipulate space-time at will (10^19 billion electron volts at a minimum, IIRC). In other words, a very long time.
Oggy
Rear Admiral
Apparently, British Telecom have successfully teleported an apple from one room to an adjacent room down in one of the research labs near Goonhilly, but nobody dared to eat it after the experiment. I don't know how it worked exactly, but it involved splitting the apple down to its component atoms and somehow transmitted them digitally to the other room where it was recreated
Unforgiven
Spaceman
I don't believe that. How do you transmit atoms digitally (ie how do you convert them from atoms to some form of digital data and how do you convert that back to atoms on the receiving end)?
How do they get past Heisenberg's principle. Why wasn't this front page news because it would be the greatest scientific discovery at least since the transistor?
I think somebody's bulling today
Afterall, if the apple stayed in tact, can you imagine how much information that would be (Star trek was probably right)
It'd be like
Atom = Well how many variables of this can there be? So perhaps it'd take say 500kb just to describe 1 atom
Quite a few terrabytes
Even a pin would be a bugger to do
Afterall, if the apple stayed in tact, can you imagine how much information that would be (Star trek was probably right)
It'd be like
Atom = Well how many variables of this can there be? So perhaps it'd take say 500kb just to describe 1 atom
Quite a few terrabytes
Even a pin would be a bugger to do
Unforgiven
Spaceman
You *can't* describe an atom. You can't know everything just as precise at the same time. If you know it's position exactly, you have no data at all about it's speed and direction, and vice versa. That's Heisenberg's uncertenty principle, and the reason transportation cannot be done by converting mass into a datastream.
Of course, Star Trek has a Heisenberg compensator for this, but no one knows how that works.
AFAIK, the only successful “teleportation” that has been achieved to date involved only photons (which are massless) in an experiment conducted by scientists at the California Institute of Technology and the University of Aarhus (Denmark) in 1998.
However, I read last year that scientists at Aarhus may be on the verge of teleporting matter for the very first time, though the essence of the experiment will be the “transfer” of the magnetic field of one macroscopic cloud of atoms (probably cesium) to another such cloud. The key to the transfer will be the fact that the two clouds are “entangled” (i.e., on the quantum level), allowing the manipulations of one to be reflected simultaneously in the other (which thus “gets around” the Heisenberg uncertainty principle). So far, the scientists have been successful in inducing a short-lived entanglement between the otherwise separate clouds.
The work is supposed to benefit the development of quantum computers and new encryption techniques.
However, I read last year that scientists at Aarhus may be on the verge of teleporting matter for the very first time, though the essence of the experiment will be the “transfer” of the magnetic field of one macroscopic cloud of atoms (probably cesium) to another such cloud. The key to the transfer will be the fact that the two clouds are “entangled” (i.e., on the quantum level), allowing the manipulations of one to be reflected simultaneously in the other (which thus “gets around” the Heisenberg uncertainty principle). So far, the scientists have been successful in inducing a short-lived entanglement between the otherwise separate clouds.
The work is supposed to benefit the development of quantum computers and new encryption techniques.
-<Stiletto>-
Spaceman
Also known as the amazing physics-nullifier which magically avoids all kinds of nasty physics problems.
Well really, I think it's a bit over-hyped. It wasn't the REAL 'poof' teleportation of a photon, but the transfer of properties which made photon X have the same properties of photon Z using photon Y as a middleman to carry this thing out. It wasn't just a "poof it's not there any more!" It was more like "Hey, we cloned the properties on a nearby photon and removed it from the original at the same time!"
Feel free to correct me if I got this wrong. I read it a while back.
I think that’s quite right. But that raises the issue of what we do and/or should mean by the word “teleportation”. More than a few years back, there was a book (written by a physicist, I believe) discussing the feasibility of Star Trek’s technology, including the transporter. I recall the book noting that there is some question whether the Trek-heads envision teleportation as really the moving of the same atoms from one place to another, or only the transfer and imprinting of the quantum information of one object (or person) onto a separate but quantitatively identical collection of atoms. How else, for example, to explain the respective episodes from the original series and NG involving two Kirks and two Rikers? (Of course, that also raises no end of metaphysical quandaries.
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