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netcat

Alice and Bob share an entangled state.

Can Alice signal to Bob (yes or no) through the entangled state of the particles?

Say that Alice has 2 entangled photons and sends one photon to Bob. Can Alice later determine whether Bob will measure up or down through interactions with the photon that she kept?

Why would this not be possible?
Does quantum teleportation not make such behavior possible?
Empress Palpatine
I think there are differences of opinion on this sort of thing. Some quantum mechanics folks would say the particles have instant communication, but others would say, no way, that would violate the light speed limit! That would be the relativity folks.

Then, you could just ask Hayden Christensen in "Jumper." wink.gif

Seriously, though, I'd like to hear the experts on this board say what they think.
netcat
Thanks for you reply,

I suppose that the rules of the quantum world just cannot be made to fit inside the classical mode of understanding that my brain requires.

What I am trying to do is come up with a way to transmit bits that are in a superposition of 0 and 1, and decide later whether each bit will be 1 or 0 when measured.

If this were possible, one could download large files (ex: the latest iso of Ubuntu) before it had been published on the internet. It would indeed solve some of the most difficult problems in computer networking such as congestion control, quality of service, and multicast. One could simply download blank-bits from their ISP at a constant bit rate and consume the bits as you surf the web.

But according to the quantum teleportation protocol, (http//www.quantiki.org/wiki/index.php/Teleportation) in order to transmit a quantum state to Bob, Alice must transmit not only the entangled states (in a classical manner) but ALSO transmit (classically) the result of her interaction with her half of the bell state.

In this case, Alice might as well just wait and send the 1s and 0s to Bob after the iso is published rather than sending the entangled states ahead of time, then sending more classical bits to Bob after the iso is published.

Is it even possible to transport a KNOWN quantum state via teleportation? All of the articles I find discuss transmitting an UNKNOWN quantum state to Bob but do not comment on whether it is necessary for the transported state to be unknown.

Quantum dense coding is probably closer to what I an looking for, but I am still puzzled about the differences between quantum information and classical information.


Does anybody know of a way to accomplish what I am trying to do?
Or could someone maybe formulate my problem in a simpler fashion so that it is clear why it will not work?

I have been dying to put this to rest but for some reason I cannot get this idea out of my head or convince myself that it not possible.

thanks




DavidD
QUOTE (netcat+Jun 25 2008, 10:45 PM)
Alice and Bob share an entangled state.

Can Alice signal to Bob (yes or no) through the entangled state of the particles?

Say that Alice has 2 entangled photons and sends one photon to Bob. Can Alice later determine whether Bob will measure up or down through interactions with the photon that she kept?

Why would this not be possible?
Does quantum teleportation not make such behavior possible?

I think your question is related does it is possible to comunicate through entanglement faster than light. Then answer is no, becouse in all quantum teleportatinos mechanisms need classical chanel also, thus to comunicate with infinity speed is imposible.
netcat
Hi Dave,

I agree that entanglement and teleportation to not allow ftl communication.

The essence of my superposition network was to eliminate contention for network resources by doing all the work ahead of time. Every bit in the iso file would have to be transferred from the ubuntu server to the client's computer just like normal. But rather than waiting until the day of release and having everyone trying to download the file at the same time, the clients would be able to start the download ahead of time.

So its really about a time-shifted or delayed decision (sort of) where the determination of the bit is deferred until after its transmission.
Sandra doliak
QUOTE (Empress Palpatine+Jun 26 2008, 02:50 AM)
but others would say, no way, that would violate the light speed limit! That would be the relativity folks.

.

Hi!

No, they would be wrong then!

The particles are entangled , they are connected.

They "others" only say that it "exceeds" the speed limit because the photon "jumps" to (any, assume 1000 KM ) distance, in "no time" (instantly) or "infinitesimal small amount of time", when doing the (beloved father of gravities formula) s= d/t, d= 1000 KM, t= 0, dividing by zero equals the humble infinity.

We all doubt that ANYTHING can travel at infinity speed, so is it not obvious?
That if nothing can travel at infinity speed, than that theory that proves it does, is incorrect?


Its like a wormhole, it can travel through HUGE distances in "small" amounts of time (notice I said "small"), But with particles, it is infinitely small (instant), they are entangled.

Sandra biggrin.gif
Delia
Hello, Sandra darling biggrin.gif xxxxx ..... just a thought; 'entanglement' may be merely an illusionary manifestation of hyperspatial 'structure' existing outside our apparent dimensional existance.
Take care, and if your dildo ever malfunctions - you know who to contact. laugh.gif
netcat
Wow, thats quite an angle!

I'm not sure what kind of spooky action you are referring to unsure.gif, but I think the best way to think about it is that the wave equation is simply a mathematical representation of what we know about the system, so when we gain knowledge about one subsystem it necessarily changes what we know about the system as whole.
DavidD
QUOTE (netcat+Jun 27 2008, 10:01 PM)
Hi Dave,

I agree that entanglement and teleportation to not allow ftl communication.

The essence of my superposition network was to eliminate contention for network resources by doing all the work ahead of time. Every bit in the iso file would have to be transferred from the ubuntu server to the client's computer just like normal. But rather than waiting until the day of release and having everyone trying to download the file at the same time, the clients would be able to start the download ahead of time.

So its really about a time-shifted or delayed decision (sort of) where the determination of the bit is deferred until after its transmission.

But HDD have limited spped of about 50MB/s and transfer connection still is of light speed, but to "thin" chanel. So if you would expand classical chanel and would expand hard disk speed, then you would be able to download ISO faster than per one second. So you searching somthing not there...
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