Quantum Teleportation 89 miles!

Originally posted by Arbitrageur

Originally posted by balon0
Wow imagine the time when our cellphones can use quantum internet. Mass information can be shared instantly.

There's nothing in that explanation that says it will be any faster.

Cell phone signals already travel at the speed of light.

In their experiment they sent a photon 89 miles at the speed of light. That's when they transferred the information instantly. But they can't transfer the information instantly without sending something at the speed of light first, so it's still limited to the speed of light just like what we have now.

It's no faster than what we already have.

Actually this is not true. Quantum entanglement is an instantaneous process. It *is* faster than light.

Originally posted by BuckWilder
And the speed at which the photon initially traveled to cross the 89 miles distance has absolutely nothing to do with the supposed FTL travel of information between entangled particles, which is what these experiments are about.

It has everything to do with practical applications for people wanting to send information faster than light, using the method in this experiment. They didn't send anything faster than light until they sent the entangled photon slightly slower than light first.

Originally posted by Smack

Wikipedia: Quantum teleportation, or entanglement-assisted teleportation, is a process by which a qubit (the basic unit of quantum information) can be transmitted exactly (in principle) from one location to another, without the qubit being transmitted through the intervening space.

This would, in theory, allow for instantaneous communications (limited by technology) over vast, even interstellar distances.

You need to read a bit further:

However, it does not immediately transmit classical information, and therefore cannot be used for communication at superluminal (faster than light) speed.

Originally posted by angrysniper

Originally posted by Arbitrageur

Originally posted by balon0
Wow imagine the time when our cellphones can use quantum internet. Mass information can be shared instantly.

There's nothing in that explanation that says it will be any faster.

Cell phone signals already travel at the speed of light.

In their experiment they sent a photon 89 miles at the speed of light. That's when they transferred the information instantly. But they can't transfer the information instantly without sending something at the speed of light first, so it's still limited to the speed of light just like what we have now.

It's no faster than what we already have.

Actually this is not true. Quantum entanglement is an instantaneous process. It *is* faster than light.

I didn't say quantum entanglement wasn't faster than light.

reply to post by Arbitrageur

It has everything to do with practical applications for people wanting to send information faster than light, using the method in this experiment. They didn't send anything faster than light until they sent the entangled photon slightly slower than light first.

I know, you are right in a sense, but that isn't the debated part of FTL information travel in this case.

Once the photon has traveled the distance and is 89 miles apart, information seemingly travels FTL between entangled particles. This is the FTL travel you suggested was impossible because of the fact that the entangled particle needs to travel at no faster than the speed of light first.

Once the particles are apart, you could in theory have FTL communications by manipulating one of the entangled particles. The fact that one particle needs to travel first is irrelevant to the point.

However it still seems impossible because there still needs to be a convential communication about the manipulation between the locations.

I'll dig up a previous experiment that explains it better.

Originally posted by angrysniper

Originally posted by Arbitrageur

Originally posted by balon0
Wow imagine the time when our cellphones can use quantum internet. Mass information can be shared instantly.

There's nothing in that explanation that says it will be any faster.

Cell phone signals already travel at the speed of light.

In their experiment they sent a photon 89 miles at the speed of light. That's when they transferred the information instantly. But they can't transfer the information instantly without sending something at the speed of light first, so it's still limited to the speed of light just like what we have now.

It's no faster than what we already have.

Actually this is not true. Quantum entanglement is an instantaneous process. It *is* faster than light.

It seems to be from our current perspective but I believe there is actually another mechanism that allows the travel of information between these particles. But that's another story.

The way how quantum mechanics and specifically entanglement works is that the results of the measurements of the particles' quantum states needs to be corroborated with each other to have a meaningfull result.

This is a very similar previous experiment,

arxiv.org...

However, a major restriction in this experiment is that the unknown quantum state cannot directly come from outside.

Charlie dis- tributes an entangled pair of photons 2 and 3 to Alice and Bob, where Bob is at a distant location. Due to the nite size of the telescopes Bob and Charlie can use and the di raction limit, Bob will receive the signal photon with very high loss. Alice then performs a joint Bell-state measurement (BSM) on the initial particle and one of the entangled photons from Charlie, projecting them onto an entangled state. After she has sent the result of her measurement as classical information to Bob, he can perform a unitary transformation (U) on his photon to obtain the initial state.

en.wikipedia.org...

Quantum teleportation (QT), or entanglement-assisted teleportation, is a process for the transmission of information utilising quantum physics to provide a level of secrecy to the information transmitted. QT is sometimes mistaken for a process that can transport matter, this is not the case, and a second method of transmission is required between the sender and receiver of the message to exchange information required for decoding the message, however this channel does not require encryption or secrecy.

Quantum teleportation, or entanglement-assisted teleportation, is a process by which a qubit can be transmitted exactly (in principle) from one location to another, without the qubit being transmitted through the intervening space. It is useful for quantum information processing, however it does not immediately transmit classical information, and therefore cannot be used for communication at superluminal (faster than light) speed. Quantum teleportation is unrelated to the common term teleportation - it does not transport the system itself, and does not concern rearranging particles to copy the form of an object. .

reply to post by Clairaudience


Thanks for the link. This looks like a helluva read and I'm gonna check it out. I'm only on chapter three, but I can already tell that this story is going deep. Thanks again.