Transferring information faster than light?

Zacharine

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Koloman Varady said:
That interpretation has trouble (I think that's the one they call the Copenhagen interpretation) because the whole "observing" thing is pretty weird. Not only does it raise weird questions about what is an observer (if you observe something, is it still in a superposition until I observe it? does it have to be human? does it need a PhD in physics?) but the whole process of the "collapse of the wavefunction" isn't even a process that can be described by Shrodinger's equation (which describes quantum mechanics).
Actually, to be more precise about the collapse of the wave-function and the 'observer' here's a slightly more technical explanation that deals away with the misunderstandings that crop up with these terms:

In macroscopic world, when two objects (even if they are identical) collide you can tell which is object A and which is object B both before and after the collision if you only do not take your eyes off of them. Their speed and positions are always known.

Now take for example two electrons. They are represented by a wave-function which describes their state in terms of probabilities. When two electrons collide, you can't actually tell which is electron A and which is electron B. To an outside observer, they are interchangeable. And thus, to describe this pair of electrons, you need a combined wave-function, made up from the two individual wave-functions.

During this time of interchangeability, the electrons are in a state of superposition: out of all possible trajectories for the electrons following the impact, both the electron A and B are at both, neither, just one and just the other of these trajectories.

However, when a new event occurs, a second collision with Electron C for example, the combined wave-function of A and B are resolved: We know A collided with C over here and B continued towards there. The combined wave-function of A and B collapsed, as the interchangeability of the particles ceased.

This was caused by the particle C, who in this case acted as the observer. So when in QM we talk of an observer, we actually mean any event that solves the wave-function-indeterminancy. The term 'Observer' is used due to the origins of this realization in the double-slit experiment: It is impossible to construct a device that can observe the slit the electron goes trough, without the device at the same time acting as a sufficient outside influence to collapse the wave-function. The observing device, just by taking a measurement, disturbs the observed particle enough to solve the indeterminancy.
 

Grounogeos

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The speed of light is roughly 186,000 miles per second. I highly doubt anything other than light can even go that fast, let alone faster.
 
Mar 9, 2009
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Random information is faster then light. Lets say for instance that you a see a video of your friend's foot. Now lets say you know that he either wears green socks or red socks, and he never mixes them. If you see the color of one sock on one foot, you automatically know the color of the other sock on the other foot faster then the speed of light.

But your string example is nifty. I don't really know how to reason that one.
 

sma_warrior

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mrpenguinismyhomeboy said:
Random information is faster then light. Lets say for instance that you a see a video of your friend's foot. Now lets say you know that he either wears green socks or red socks, and he never mixes them. If you see the color of one sock on one foot, you automatically know the color of the other sock on the other foot faster then the speed of light.

But your string example is nifty. I don't really know how to reason that one.
You're wrong on both counts.

First, your brain takes time to process that information SLOWER than the speed of light, though to you it seems instantaneous (brain has to acknowledge/see that it is your friend, which can only be done at the speed of light at best in order to receive the signal that it's your friend. Your brain THEN computes what colour the socks are based on wavelength, THEN translates that one colour sock means the other is the same.

Two, the string example is NOT nifty - it has the same problem your brain does in that the time taken between start and finish is imperceptible to you.
 
Mar 9, 2009
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sma_warrior said:
mrpenguinismyhomeboy said:
Random information is faster then light. Lets say for instance that you a see a video of your friend's foot. Now lets say you know that he either wears green socks or red socks, and he never mixes them. If you see the color of one sock on one foot, you automatically know the color of the other sock on the other foot faster then the speed of light.

But your string example is nifty. I don't really know how to reason that one.
You're wrong on both counts.

First, your brain takes time to process that information SLOWER than the speed of light, though to you it seems instantaneous (brain has to acknowledge/see that it is your friend, which can only be done at the speed of light at best in order to receive the signal that it's your friend. Your brain THEN computes what colour the socks are based on wavelength, THEN translates that one colour sock means the other is the same.

Two, the string example is NOT nifty - it has the same problem your brain does in that the time taken between start and finish is imperceptible to you.
Really? Damn.

Oh well.
 

kahlzun

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Sep 9, 2009
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Don't forget that gravitational effects exceed lightspeed.

ie:the Earth is attracted towards where the sun is, not where is was 8 minutes ago.
 

dantoddd

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Malcheior Sveth said:
I think Tachyons are the only particles predicted to violate locality, and they aren't even meaningful physical objects. They just show up in a nice way in the mathematics of the Standard Model but they aren't necessary.

Beyond that, none of the quantum effects that have do have information traveling faster than the speed of light can exist for a long enough time (at least in (3,1) space, I dunno about (2,2) twistor space[black holes]). Any particle that is not on mass shell or photon that is not on the light cone will decay in < O(10^-23) time, AND we cannot see these "virtual particles"; they are basically what we think happens in the middle of an interaction, and all we see from that are what goes in and what comes out. Only real particles come out, and only those can travel any meaningful distance.

As for quantum entanglement, in theory it doesn't happen on a large enough scale to be useful, although at what point things stop being superpositions of probabilities (i.e. operating by quantum mechanics rules) and become normal macroscopic objects (i.e. operating by classical laws) is still an open problem in quantum mechanics.
1)Entanglement doesn't allow for information transfer, that can be proven fairly easily.

2)I'm no expert, but do virtual particles really exist? It seems to me virtual particles are mathematical baggage left over from the perturbative treatment of Hamiltonians. If we had exact solution for all Hamiltonians then we wouldn't have virtual particles
 

Malcheior Sveth

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dantoddd said:
Malcheior Sveth said:
1)Entanglement doesn't allow for information transfer, that can be proven fairly easily.

2)I'm no expert, but do virtual particles really exist? It seems to me virtual particles are mathematical baggage left over from the perturbative treatment of Hamiltonians. If we had exact solution for all Hamiltonians then we wouldn't have virtual particles
We have no way to confirm or deny experimentally whether or not virtual particles actually exist, for the reason I stated. There is no way to look "inside" a collision of two particles to see what is actually going on, we only see what goes in and what comes out. If particles that were not on-mass-shell came out of a collision it would completely destroy special relativity.

kahlzun said:
Don't forget that gravitational effects exceed lightspeed.

ie:the Earth is attracted towards where the sun is, not where is was 8 minutes ago.
No, it doesn't. Gravitation propagates at the speed of light in general relativity.

See: http://math.ucr.edu/home/baez/physics/Relativity/GR/grav_speed.html
 

angelzsniper

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Nov 17, 2009
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Bump. And i kind of realized this got off-topic. I wasn't asking if mass could travel faster than light. I was wondering if it could be theoretically possible to affect something far away (you don't necessarily have to be moving stuff at the speed of light. For example, if I have a really long stick and I poke a button very very far away, I didn't necessarily move the stick at 900 mph, I just moved the stick a few inches and the end moved relative to my hand. It's still confusing. Help.
 

Baneat

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Jul 18, 2008
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No offense, but nobody's going to achieve what theoretical physicists have been attempting to crack for a long, long time on the Escapist forums.
 

ModReap

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Apr 3, 2008
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Actually tugging the string would not have that effect.
1. Get a high speed camera
2. Tape you doing the thing

If you put the camera close enough to the string you would see one side stretch and that stretchy bit moves all the way along the string until it hits your friend's side where it then compresses to normal when he moves forward.
 

cuddly_tomato

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Nov 12, 2008
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I know someone who is into this kind of thing. Let me go and ask him what he thinks of the idea...



He said that he doesn't think it is possible, sorry.

Might well be possible, but if so then a lot of physics is a lot of crap.
 
Feb 13, 2008
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angelzsniper said:
So will you be able to take something like this into a much larger scale (doesn't have to be a string) in which you pull/push on something and it happens somewhere else a few lightyears away? Just something to think about...
)
Basically, the pulling of the string is the transferral of potential energy(stretch) to kinetic energy(movement). That's a lot slower than light because it involves transferrence as well as passage.

What Einstein's equation does prove, however, is that if we can slow light down - by temporarily forcing it to form photons rather than wave form - we can achieve FTL travel. Or you can just wormhole it.

Nice first post though.

Actually, Einstein's equation only works within gravity wells, so a sufficient gravity well would alter physical properties. Unfortunately, proving or observing that cause problems with quantum physics.