Faster than light communication???

[Janus]

I'm trying my best to follow all this but I'm struggling.

 

I'm not sure what Swan means here' date=' does s/he mean once you've spun the sender and measured the receiver that the linked pair is broken so you can only send one "bit" of data then that's it, you need to create a new pair...

Or is there a way to preserve the pair??

 

 

[/quote']

 

Here in lies the problem. When two particles are entanged, the state of either particle is indeterminent. If you do anything to either, both particles instantly take on opposite states. There lies the problem. If the "receiver" checks his particle, he doesn't know whether he is measuring a state caused by the "transmitter", or whether he himself caused the the particles to decide on a state.

[MadScientist]

Here in lies the problem. When two particles are entanged, the state of either particle is indeterminent. If you do anything to either, both particles instantly take on opposite states. There lies the problem. If the "receiver" checks his particle, he doesn't know whether he is measuring a state caused by the "transmitter", or whether he himself caused the the particles to decide on a state.

 

Thanks for that Janus and Swan.

At my level I'm happy to just make do with a simple explanation for now.

 

So how does the transfer between an entangled pair work??

At the moment the way I see it passing a photon uses a different method to passing data which involves spinning something at a different speed.

So how would both methods work, if there are two methods.

 

 

And if it's right that you can pass a photon, isn't a photon a type of electron or positron or something like that?? I was wondering if we should ever find a means of creating stable entangled pairs if it could be used as a means of passing electricity because the uses for that would be incredible.

[Guest Penetrator]

As anyone got news of the FTLC sys in the states ??

[Guest Penetrator]

As anyone got news of the FTLC sys in the states ??

[hoagy]

Here's a possible method for faster than light communication:

 

Imagine two star systems (A and B) separated by a distance of 10 light years, with a laser beam splitter exactly half-way between them. The laser beam splitter creates two entangled beams of laser light (A and B), each headed toward one of the two star systems.

 

After 5 years, the entangled laser beams reach the two star systems. At each star system is a receiver for the entangled laser beams consisting of a double-slit detector. If the two entangled beams arrive at each star system undisturbed, they will both create an interference pattern on their respective double-slit detector. This is because the probabilistic wave function for the entangled beams has not collapsed.

 

If laser beam A is disturbed (i.e. observed) just before reaching its double-slit detector, then the wave function for that beam collapses, as does the wave function for laser beam B just before it reaches its detector. This happens instantaneously across the 10 light year distance. The consequence of this is that laser beam B will NOT create an interference pattern at its double-slit detector.

 

It’s not hard to imagine that one can create a pattern of disturbance on laser beam A that can be translated instantaneously to the detector of laser beam B simply by observing whether there is an interference pattern or not. If the beam is continuous you can send a message just by encoding binary over short time period "frames". Interference pattern during the frame = 0. No interference = 1. From there all the complexity of digital communication protocols can be layered on top of this simple transport mechanism. In this sense, faster-than-light communication can be achieved.

 

Follow this link for a more in-depth discussion and implications for space exploration:

 

http://www.seti.org.au/spacecom/quantumcom.html

[Mart]

There is no way to preserve the pair. Once you make a measurement, i.e. do anything that interacts with the particle, the entanglement is destroyed.

That's interesting. On another thread it was said that things don't exist unless they can interact with the universe. But if a thing is for the time being not interacting what is it doing? And where is it?

[Sayonara]

Firstly that was not said; what was said was that if it can't interact with the universe (and interact is a broad term in this sense) then it should not be considered a part of it.

 

Secondly, entanglement is a property of the pair. It is not a third entity of its own.

[Mart]

Firstly that was not said; what was said was that if it can't interact with the universe (and interact is a broad term in this sense) then it should not be considered a part of it.

 

Secondly' date=' entanglement is a property of the pair. It is not a third entity of its own.[/quote']

I'm struggling with the meaning of the word considered. Does it mean that things exist that don't interact with the universe?

[Sayonara]

Possibly, I can't really think of any off the top of my head.

 

The point is that if we can't interact with something in any way, and it can't interact with anything that we do interact with (which includes everything from puppies to gravitational fields in distant galaxies) we don't need to worry about it. Well we won't anyway, since we would not be able to detect it.

[ydoaPs]

would you consider something beyond the event horizon of a black hole in our universe?

[Mart]

So can interact is not the same as is interacting?

If a thing is for the time being not interacting what is it doing? And where is it?

[Sayonara]

To yourdad:

 

Yes, unless there's any reason to believe that it has gone somewhere else.

[Sayonara]

So can interact is not the same as is interacting[/i']?

Apparently not.

 

If a thing is for the time being not interacting what is it doing? And where is it?

When is anything that belongs to this universe 'not interacting'?

[J.C.MacSwell]

Here's a possible method for faster than light communication:

 

Imagine two star systems (A and B) separated by a distance of 10 light years' date=' with a laser beam splitter exactly half-way between them. The laser beam splitter creates two entangled beams of laser light (A and B), each headed toward one of the two star systems.

 

After 5 years, the entangled laser beams reach the two star systems. At each star system is a receiver for the entangled laser beams consisting of a double-slit detector. If the two entangled beams arrive at each star system undisturbed, they will both create an interference pattern on their respective double-slit detector. This is because the probabilistic wave function for the entangled beams has not collapsed.

 

If laser beam A is disturbed (i.e. observed) just before reaching its double-slit detector, then the wave function for that beam collapses, as does the wave function for laser beam B just before it reaches its detector. This happens instantaneously across the 10 light year distance. The consequence of this is that laser beam B will NOT create an interference pattern at its double-slit detector.

 

It’s not hard to imagine that one can create a pattern of disturbance on laser beam A that can be translated instantaneously to the detector of laser beam B simply by observing whether there is an interference pattern or not. If the beam is continuous you can send a message just by encoding binary over short time period "frames". Interference pattern during the frame = 0. No interference = 1. From there all the complexity of digital communication protocols can be layered on top of this simple transport mechanism. In this sense, faster-than-light communication can be achieved.

 

Follow this link for a more in-depth discussion and implications for space exploration:

 

http://www.seti.org.au/spacecom/quantumcom.html[/quote']

 

The way I understand it:

 

If you observe a photon before it reaches the two slits, so that it could then enter either slit an interference pattern should still result.

In 3 slit experiments with a detector at one slit you should see a combination of no interference detections at that slit and interference otherwise between the remaining 2 slits.

 

So I don't see the collapse of the wave function with respect to interference as you have just described.

 

Please correct me if I am wrong.

 

I am not convinced that a message could not be sent FTL on a statistical basis. ( By altering the pattern from a random distribution over a number of tests on polarization for example) but it would sure change our perception of SR (or we could send messages into the past by prior arrangements of Code)

 

Sorry if that was vague.

[Mart]

When is anything that belongs to this universe 'not interacting'?

So are you saying that everything we consider in our universe is continually interacting with something else?

[syntax252]

I know that faster than light travel is impossible. Is there a way to send a signal over a distance of one light year in less than a year?

 

I read something the other day to the effect that gravity was not limited by the speed of light. As I understand it, the sun has a certain gravitational effect on the Earth and if something happened to the sun to suddenly cause it to have less mass, it would affect the Earth immediately, rather that the 500 or so seconds that it takes light to get here.

 

So, if all bodies in the big U are affected to some extent by all other bodies in the big U........then, maybe

 

If there was some way to affect gravity and make that affect into a pattern, and if a receiver was able to interpet that pattern it would be instantanious, right?

[Sayonara]

So are you saying that everything we consider in our universe is continually[/i'] interacting with something else?

I was saying I can't think of anything that isn't.

 

That's beside the point though, as it only needs to be able to interact. It doesn't actually have to do it constantly.

[Dror]

By saying that entangled pairs are no longer entangled at encoding/decoding (Or any other means of disruption whatsoever) you are bassicaly saying that entanglment is nothing more then two particles born with the same properties. And, by that you are dismissing the whole notion of entanglment.

That kind of contradicts the whole meaning of 'entanglment'.

It makes an entangled pair nothing more then 2 particles with the same properties somewhere in the universe. (Sorry for repeating my self)

 

A question: Does interfering with the first entangled particle causes the same interference in the second? Or for argument's sake, the implication of intereference on the first particle doesn't have to be the same as the implication on the second particle. As long as there is SOME implication on the second.

 

If not, then entanglment is dismissed.

 

If it is, then communication between entangled particles is possible with a very very clever protocol, The way I see it. (At no time at all, ofcourse).

[RICHARDBATTY]

The way I see it is that any communication traveling ftl and going back in time would reach a point of equilibrium. By this I mean that the time it took to travel "x" distance would not have passed there by making that part of the journey instantaneous. Once the signal reached this point its entire journey would be instant and therefore causality would not be affected. If you want to dispute this remember I have the IQ of toast.

[swansont]

By saying that entangled pairs are no longer entangled at encoding/decoding (Or any other means of disruption whatsoever) you are bassicaly saying that entanglment is nothing more then two particles born with the same properties. And' date=' by that you are dismissing the whole notion of entanglment.

That kind of contradicts the whole meaning of 'entanglment'.

It makes an entangled pair nothing more then 2 particles with the same properties somewhere in the universe. (Sorry for repeating my self)

 

A question: Does interfering with the first entangled particle causes the same interference in the second? Or for argument's sake, the implication of intereference on the first particle doesn't have to be the same as the implication on the second particle. As long as there is SOME implication on the second.

 

If not, then entanglment is dismissed.

 

If it is, then communication between entangled particles is possible with a very very clever protocol, The way I see it. (At no time at all, ofcourse).[/quote']

 

No need to post identical statements in multiple threads. I think you are trying to project what you want entanglement to be onto the physics, rather than accept that sometimes physicists use words that have certain lay definitions to mean something specific, and slightly different, in the physics world.