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General Discussions => Skepticism / Science Talk => Topic started by: gebobs on September 11, 2019, 11:22:35 AM

Title: Scientists Just Teleported an Object Into Space for the First Time
Post by: gebobs on September 11, 2019, 11:22:35 AM
https://time.com/4854718/quantum-entanglement-teleport-space/?fbclid=IwAR3Rb8eEZxOSvQGd3kmd3nFvIgly8E2qBkeAglxnp13qTJ5sUEtVgAFmXDQ

Quantum entanglement isn't in my wheelhouse. If some of you smart guys would explain this to me, I'd appreciate it. I don't get the part about "teleportation" or "beaming up" photons.

From the article in Time:

A team of researchers in China sent a photon from the ground to an orbiting satellite more than 300 miles above through a process known as quantum entanglement, according to MIT Technology Review. It’s the farthest distance tested so far in teleportation experiments, the researchers said.

For about a month, the scientists beamed up millions of photons from their ground station in Tibet to the low-orbiting satellite. They were successful in more than 900 cases.

“This work establishes the first ground-to-satellite up-link for faithful and ultra-long-distance quantum teleportation, an essential step toward global-scale quantum Internet,” the team said in a statement, according to MIT Technology Review.

The MIT-owned magazine described quantum entanglement as a “strange phenomenon” that occurs “when two quantum objects, such as photons, form at the same instant and point in space and so share the same existence.” “In technical terms, they are described by the same wave function,” it said.

The latest development comes almost a year after physicists successfully conducted the world’s first quantum teleportation outside of a laboratory. Scientists at that time determined quantum teleportation, which is often depicted as a futuristic tool in science-fiction films, is in fact possible.
Title: Re: Scientists Just Teleported an Object Into Space for the First Time
Post by: stands2reason on September 11, 2019, 01:01:54 PM
This article (https://www.askamathematician.com/2017/07/teleportation-in-space/) is the best explanation I've seen. It is not "teleportation", it is quantum entanglement. Short answer: quantum entanglement can be established (quantum state can be sent) over radio (photons). This experiment, if valid, would be a record for longest distance of doing this.
Title: Re: Scientists Just Teleported an Object Into Space for the First Time
Post by: Shibboleth on September 11, 2019, 01:07:30 PM
I mean it is cool up until people get sent to hell in a spaceship and they sew their own eyes shut.
Title: Re: Scientists Just Teleported an Object Into Space for the First Time
Post by: wastrel on September 11, 2019, 02:55:06 PM
This article (https://www.askamathematician.com/2017/07/teleportation-in-space/) is the best explanation I've seen. It is not "teleportation", it is quantum entanglement. Short answer: quantum entanglement can be established (quantum state can be sent) over radio (photos). This experiment, if valid, would be a record for longest distance of doing this.

I thought a rule of quantum entanglement is that no information can be transferred.
Title: Re: Scientists Just Teleported an Object Into Space for the First Time
Post by: gebobs on September 11, 2019, 03:16:58 PM
Oh I think I see what it's saying. They successfully sent 900 photons up yonder while the second of the entangled pair was on Earth and then they successfully "transported" a qubit thus. Is that it?
Title: Re: Scientists Just Teleported an Object Into Space for the First Time
Post by: The Latinist on September 11, 2019, 03:27:40 PM
This article (https://www.askamathematician.com/2017/07/teleportation-in-space/) is the best explanation I've seen. It is not "teleportation", it is quantum entanglement. Short answer: quantum entanglement can be established (quantum state can be sent) over radio (photos). This experiment, if valid, would be a record for longest distance of doing this.

I thought a rule of quantum entanglement is that no information can be transferred.

No information can be transmitted faster than light, but that’s not what they’re doing here.  In order to extract the information in the qubit without destroying entanglement, they have to measure both quints using the same method, then compare the two.  Only by comparing them can they know what the state was.  That requires a classical communication channel, meaning the info can’t move faster than light.
Title: Re: Scientists Just Teleported an Object Into Space for the First Time
Post by: wastrel on September 11, 2019, 03:47:03 PM
This article (https://www.askamathematician.com/2017/07/teleportation-in-space/) is the best explanation I've seen. It is not "teleportation", it is quantum entanglement. Short answer: quantum entanglement can be established (quantum state can be sent) over radio (photos). This experiment, if valid, would be a record for longest distance of doing this.

I thought a rule of quantum entanglement is that no information can be transferred.

No information can be transmitted faster than light, but that’s not what they’re doing here.  In order to extract the information in the qubit without destroying entanglement, they have to measure both quints using the same method, then compare the two.  Only by comparing them can they know what the state was.  That requires a classical communication channel, meaning the info can’t move faster than light.

I see, thanks for clarifying
Title: Re: Scientists Just Teleported an Object Into Space for the First Time
Post by: Shibboleth on September 11, 2019, 04:21:44 PM
This article (https://www.askamathematician.com/2017/07/teleportation-in-space/) is the best explanation I've seen. It is not "teleportation", it is quantum entanglement. Short answer: quantum entanglement can be established (quantum state can be sent) over radio (photos). This experiment, if valid, would be a record for longest distance of doing this.

I thought a rule of quantum entanglement is that no information can be transferred.

No information can be transmitted faster than light, but that’s not what they’re doing here.  In order to extract the information in the qubit without destroying entanglement, they have to measure both quints using the same method, then compare the two.  Only by comparing them can they know what the state was.  That requires a classical communication channel, meaning the info can’t move faster than light.

So what is the benefit of something like this? If you have to communicate the comparison at normal speeds with normal communication methods why not just use that normal communication method to tell people what you want or what you want them to do.
Title: Re: Scientists Just Teleported an Object Into Space for the First Time
Post by: The Latinist on September 11, 2019, 05:25:19 PM
This article (https://www.askamathematician.com/2017/07/teleportation-in-space/) is the best explanation I've seen. It is not "teleportation", it is quantum entanglement. Short answer: quantum entanglement can be established (quantum state can be sent) over radio (photos). This experiment, if valid, would be a record for longest distance of doing this.

I thought a rule of quantum entanglement is that no information can be transferred.

No information can be transmitted faster than light, but that’s not what they’re doing here.  In order to extract the information in the qubit without destroying entanglement, they have to measure both quints using the same method, then compare the two.  Only by comparing them can they know what the state was.  That requires a classical communication channel, meaning the info can’t move faster than light.

So what is the benefit of something like this? If you have to communicate the comparison at normal speeds with normal communication methods why not just use that normal communication method to tell people what you want or what you want them to do.

I don’t know that there is a practical application, or that more is needed to justify the experiment than basic science: this experiment set a record for the distance over which entanglement has been created.  But the usually-cited purpose of such a quantum ‘communication’ channel is encryption. Quantum data sent in this manner could not be intercepted without the recipient and sender being aware of the interception, and the information that would have to be sent classically would not be sufficient to reconstruct the message. It could be used for secure key exchange over long distances.
Title: Re: Scientists Just Teleported an Object Into Space for the First Time
Post by: Noisy Rhysling on September 11, 2019, 07:08:13 PM
I mean it is cool up until people get sent to hell in a spaceship and they sew their own eyes shut.
In any event, that's just on the horizon.
Title: Re: Scientists Just Teleported an Object Into Space for the First Time
Post by: gmalivuk on September 12, 2019, 12:53:01 PM
This article (https://www.askamathematician.com/2017/07/teleportation-in-space/) is the best explanation I've seen. It is not "teleportation", it is quantum entanglement. Short answer: quantum entanglement can be established (quantum state can be sent) over radio (photos). This experiment, if valid, would be a record for longest distance of doing this.

I thought a rule of quantum entanglement is that no information can be transferred.

No information can be transmitted faster than light, but that’s not what they’re doing here.  In order to extract the information in the qubit without destroying entanglement, they have to measure both quints using the same method, then compare the two.  Only by comparing them can they know what the state was.  That requires a classical communication channel, meaning the info can’t move faster than light.

So what is the benefit of something like this? If you have to communicate the comparison at normal speeds with normal communication methods why not just use that normal communication method to tell people what you want or what you want them to do.
My understanding is that normal communication methods don't transfer (copy) qubits, they just transfer information about what a qubit was before it collapsed. Quantum computing and communication requires keeping qubits in a superposition.
Title: Re: Scientists Just Teleported an Object Into Space for the First Time
Post by: Guillermo on September 12, 2019, 01:52:27 PM
https://www.youtube.com/watch?v=DxQK1WDYI_k

Best explaination for teleporting I've seen.
Title: Re: Scientists Just Teleported an Object Into Space for the First Time
Post by: Shibboleth on September 12, 2019, 03:26:29 PM



I don’t know that there is a practical application, or that more is needed to justify the experiment than basic science: this experiment set a record for the distance over which entanglement has been created.  But the usually-cited purpose of such a quantum ‘communication’ channel is encryption. Quantum data sent in this manner could not be intercepted without the recipient and sender being aware of the interception, and the information that would have to be sent classically would not be sufficient to reconstruct the message. It could be used for secure key exchange over long distances.

I suppose but you don't need this to have that sort of end to end security. I suppose it completely cuts off any option of a man in the middle.

All that I see is that nature is a complete bitch. Oh you can do something that is instantaneous but if you try to look at it it will break. 
Title: Re: Scientists Just Teleported an Object Into Space for the First Time
Post by: gmalivuk on September 12, 2019, 03:43:38 PM
It's my understanding that ruling out MITM attacks is precisely the point. If this can be done over long distances, then even at 1bps it becomes the fastest totally secure way to share a key.
Title: Re: Scientists Just Teleported an Object Into Space for the First Time
Post by: gebobs on September 16, 2019, 10:47:08 AM

Best explaination for teleporting I've seen.

Yes very good but...

(http://www.mathfunny.com/images/mathpics-joke-meme-humor-funny-mathjoke-mathmeme-haha-pun-dog-homework-confused-cute.jpg)
Title: Re: Scientists Just Teleported an Object Into Space for the First Time
Post by: John Albert on September 16, 2019, 06:25:42 PM
This experiment really just provides more evidence for the nonlocality of quantum entanglement, by showing that entanglement can occur over astronomical distances.


This article (https://www.askamathematician.com/2017/07/teleportation-in-space/) is the best explanation I've seen. It is not "teleportation", it is quantum entanglement. Short answer: quantum entanglement can be established (quantum state can be sent) over radio (photos). This experiment, if valid, would be a record for longest distance of doing this.

I thought a rule of quantum entanglement is that no information can be transferred.

It is. You cannot use quantum entanglement to transmit information.

Here's a good explanation (https://www.quora.com/Why-is-it-not-possible-to-transmit-information-using-quantum-entanglement) of why it won't work.

Title: Re: Scientists Just Teleported an Object Into Space for the First Time
Post by: gmalivuk on September 16, 2019, 06:32:23 PM
No information can be transferred instantaneously, and the entanglement itself doesn't transfer information, but neither of those is what's going on here.
Title: Re: Scientists Just Teleported an Object Into Space for the First Time
Post by: John Albert on September 16, 2019, 06:43:10 PM
No information can be transmitted faster than light, but that’s not what they’re doing here.  In order to extract the information in the qubit without destroying entanglement, they have to measure both quints using the same method, then compare the two.  Only by comparing them can they know what the state was.  That requires a classical communication channel, meaning the info can’t move faster than light.

The action of measurement itself is problematic, even if both parties use the same method. Checking the quantum state of a particle would require an interaction with it, and the effects of individual quantum interactions are necessarily random.

So the only way to validate a change in the state would be to compare the two, which—as you pointed out—would necessitate a secondary channel of information.