Do results from quantum entanglement experiments propagate faster than light?

I know the first time I saw these "spooky action at a distance" experiments being performed, the first thing that came to mind was "Ok, did the result propagate faster than light or not?".

Oddly, I never saw anyone doing these experiments try to find out. You know that had to come up, but no one ever seemed to publish it. Or discuss it.

Other than Kantor in "Information Mechanics" it seems to be sort of taboo.

Well, John Cramer, physicist at UW and author of several books of science fiction ("Twistor" is my favorite) is going to perform some entanglement experiments with the sole question being - how fast does this actually propagate? FTL or not?

cosmiclog.msnbc.msn.com...

The Problem with Faster than light, in my opinion, is that in small distances it would mean that the effect would happen before the cause.

For example, you press a button to turn on a light, if the signal was faster than light then the light should turn on before you press the button.

But if that is true, then what happens if you dont press the button then? does the light just go out? does it never turn on in the first place? or does the universe implode?

Originally posted by Octavius Maximus
The Problem with Faster than light, in my opinion, is that in small distances it would mean that the effect would happen before the cause.

These things you speak of - Cramer wants to test all of them. He brings all three points up in the article. Is it superluminal? Can he make effects happen before their cause? If he can, what happens if he doesn't do it?

Creepy, yet compelling. I don't understand why the other people that do entanglement experiments don't test for it - actually I suspect they do but don't publish. I would - test it that is. Probably right off after I got the apparatus working dependably. Wouldn't you want to know?

The only problem with quantum entanglement is that if you want to, say, transmit a message with it between here and Alpha Centauri, you'd first have to box up one of those little half-quantums and drag it the old-fashioned way to Alpha Centauri, which at present speeds is going to take you several millennia. Not exactly speedy communication, and certainly not "faster than light," by any means.

It might come in handy for communcation for quick trips around the Solar System. But how many of them has anybody been on lately? By the time we get the technology figured out and we're doing stuff where we could practically utilize such a thing, humanity will be long gone, and there won't be anybody to talk to, FTL or otherwise.

It's really hard to stomach, but if you ever find a cheap copy, you should get "Information Mechanics" if you're into that sort of thing.

Kantor manages to derive big chunks classic physics from his theory that the universe is all data structures. The hard math sort, not blue-skying. Part of it is how entanglement "actually works", or at least it's possible to bring it under the shed of his theoretical base and fit the same experimental results.

It could be possible to entangle at a distance by "convincing" a couple of particles that they're the same. He gets past me pretty quick. Neon Haze might have more luck with it. But the bits I can read and follow are pretty interesting.

Originally posted by Octavius Maximus
The Problem with Faster than light, in my opinion, is that in small distances it would mean that the effect would happen before the cause.

For example, you press a button to turn on a light, if the signal was faster than light then the light should turn on before you press the button.

But if that is true, then what happens if you dont press the button then? does the light just go out? does it never turn on in the first place? or does the universe implode?

I do not think there is a problem. What we observe has little to do with what has happened. So we might be able to perceive the effect after the cause, but we would not be able to cancel the effect, because the cause would already have happened.

In your example, I may see the light before seeing the button pressed, but I would not be able to cancel the event, because it will already have happened, it's just that I would not have seen it.

Originally posted by Octavius Maximus
The Problem with Faster than light, in my opinion, is that in small distances it would mean that the effect would happen before the cause.

For example, you press a button to turn on a light, if the signal was faster than light then the light should turn on before you press the button.

But if that is true, then what happens if you dont press the button then? does the light just go out? does it never turn on in the first place? or does the universe implode?

Not a very good analogy. Electrical signals do not travel at the speed of light. If you had a quantum entangled light switch, the light wouldn't come on before you pressed the button, but rather the moment you press the button.

It may seem to you that a light turns on instantaneously for a normal light switch, but slow it down and you'll see the delay. It might only be a millisecond, but it is there. Electricity is rather slow in comparison to light...

You seem to be equating going faster than light as happening in the future. Not so. At leats in the context posed by this question.

What you'd want is to see the speed of the signal, not the effect, to determine whether it transmits FTL.

Granted, smaller distances make it harder to determine, but if you had a bulb on the moon and a switch on earth, you could measure it.

Lets assume you have two switches and a bulb on the moon. One is radio activated (so, speed of light transmission) and the other is a QE switch (unknown transmission speed).

For your bulb on the moon, it would take about 1.7 seconds to turn on via the radio transmission from the moment you flipped the switch.

For the QE, assuming it is instantaneous, it would be 0 seconds.

Any divergence would give you the real speed of QE particle signal transmission in relation to light speed....

It is an experiment one could do on earth, but you would need some sensitive equipment.

[edit on 22/7/07 by stumason]

Originally posted by SuicideVirus
The only problem with quantum entanglement is that if you want to, say, transmit a message with it between here and Alpha Centauri, you'd first have to box up one of those little half-quantums and drag it the old-fashioned way to Alpha Centauri, which at present speeds is going to take you several millennia. Not exactly speedy communication, and certainly not "faster than light," by any means.

Agreed - but the way I understand entanglement this may not be the only way to deal with this little problem.

Lets say we want to set up permanent communication between Alpha Centauri and Earth. What I would suggest is we would have to of set up a half way communications 'hub'. On this Hub base a single (very powerful) Laser beam would be generated. This beam is then split in to two - there fore every photon has a twin. Interfering with one beam on the quantum level will show results in the other - instantly.

Now the logistics of this set up are very close to being imposable. First is the time required to actually drop off the hub (although if you are going to Alpha anyway - simply drop it off half way).

Secondly the speed of light comes into account for the beam to actually reach the destinations (Earth and Alpha), but once the beams have arrived they will be kept on permanently, therefore any message sent by interfering with the photons at either end (or at any point along the beam for that matter) would be instantly received at the other end.

Thirdly is maintaining a constant beam - every so often something would pass to block it (our moon - but other planets, moons space debris and passably the closest star to us - Noooo it's not Alpha Centauri! it's Alpha Proxima *spelling!*) But I suppose this could be accounted for by the beams being switched on and off to a very strict schedule, meaning messages could only be sent at certain intervals.

And lastly would be the Doppler effect - but that is the least of worries compared to what I’m proposing!

What do'ya think - do I deserve the Nobel prize (if I do it ain't gonna be for spelling)

Edit: tidyup

[edit on 22/7/2007 by Now_Then]

Not a very good analogy. Electrical signals do not travel at the speed of light. If you had a quantum entangled light switch, the light wouldn't come on before you pressed the button, but rather the moment you press the button.

Yeah i know what you mean. Thanks for that!

reply to post by Now_Then


Sorry to dig up an old thread, but I must point out you've missed on thing in your analysis: not only do you need to haul the entagled particles (e.g. photons) to your destination, you also need to send some classical information to tell the other party how to measure his particle. No matter how clever your setup, there's no way to use entanglement to send information faster than the speed of light.

Originally posted by Octavius Maximus
The Problem with Faster than light, in my opinion, is that in small distances it would mean that the effect would happen before the cause.

For example, you press a button to turn on a light, if the signal was faster than light then the light should turn on before you press the button.

But if that is true, then what happens if you dont press the button then? does the light just go out? does it never turn on in the first place? or does the universe implode?

eh.. no? u press the button.. the electricity to power the light runs in the circuit to the light.. Then the light "turns on".. it doesnt matter how fast the power got to the bulb.. the bulb comes on after the power gets there.. otherwise theres no power for the light to illuminate.

im not very scientific in my explination.. but its basic reason..
at most the light comes on exactly when u hit the switch.. but not before..
if u dont flip the switch.. the light doesnt come on.. period..

or am i missing something?

[

Originally posted by stumason
Not a very good analogy. Electrical signals do not travel at the speed of light. If you had a quantum entangled light switch, the light wouldn't come on before you pressed the button, but rather the moment you press the button.

ok i didnt read it all at first.. but yah stumason was thinking what i am.. jus read his post.. again, its much more articulate