This doesn't explain clearly to me that this is teleportation.

Questions:
1. How is this different from going somewhere else and changing something to resemble something else where you just came from?
2. How much of this is facetious? I mean, did they really teleport a photon with a fax machine?
3. What kind of information about the relationship between the two photons did they measure without measuring the original photon?
4. If they teleported photon A, then why is it still at the origin in the graphic?
5. If they teleported photon A, then why is it in a different state than the disrupted photon A?
6. At what point did something get measured that would change the state?

This guy does a terrible job of presenting his facts. He's not wrong, strictly speaking, he just didn't say it in a way that made sense.

1.) "Teleportation" is a misnomer. "Quantum Teleportation" always refers to the act of destroying something at the source and recreating it at the destination.

2.) See above.

3.) It is a Bell measurement. The specifics get confusing unless you want to do a lot of reading.

The short version: The 'Bell Basis' of A-B is measured. Both qubits are destroyed. The information is sent to the person holding C, via traditional channels. The same process is performed (in reverse) on C. This creates a new copy of A, despite not knowing what it originally looked like.

Confusing as hell at first. But this is the exact experiment they did, and it works.

4.) Because he didn't make the infographic very well.

5.) See above.

6.) To measure the particle, we are bouncing electrons or light off the qubit and surrounding matter. This add energy to the system and therefore changes it's behavior. Therefore, measuring any particle changes it's state.

It's what makes Quantum Mechanics so fun!

>> ^messenger:

This doesn't explain clearly to me that this is teleportation.

When "they" talk about being able to see velocity or position, but not both... that's just a failure of technology right? There's not some weird universal law making it impossible?

>> ^Payback:

When "they" talk about being able to see velocity or position, but not both... that's just a failure of technology right? There's not some weird universal law making it impossible?


You refer to the Heisenberg Uncertainty Principle. (The more accurately you measure a particle's position, the less accurate you are regarding momentum. And vice-versa.)

And yes, the problem is primarily technological. If someone ever invents a way to peer in and measure tiny particles without some kind of energy exchange with the particle (via light or electron scatter), the whole argument pretty much becomes a moot point.

And man would THAT ever screw with quantum physics.

Soulmonarch, first, thanks for the excellent answers above. They were just enough for me to understand that something real was being measured and why I didn't understand the rest of the concept.

Now, you clearly know oodles more than I do about this stuff, but I thought that it was an absolute fact that you cannot determine both the speed/direction and position of anything, no matter how it's measured by definition of the measurement of speed/direction requiring more than one position. That's to say, I'm under the impression that the Heisenberg Uncertainty Principle has nothing to do with technology and will always be true under any conditions with any equipment in the areas where it applies, world without end, Amen. Am I wrong?>> ^soulmonarch:

>> ^Payback:
When "they" talk about being able to see velocity or position, but not both... that's just a failure of technology right? There's not some weird universal law making it impossible?

You refer to the Heisenberg Uncertainty Principle. (The more accurately you measure a particle's position, the less accurate you are regarding momentum. And vice-versa.)
And yes, the problem is primarily technological. If someone ever invents a way to peer in and measure tiny particles without some kind of energy exchange with the particle (via light or electron scatter), the whole argument pretty much becomes a moot point.
And man would THAT ever screw with quantum physics.

>> ^messenger:

...I thought that it was an absolute fact that you cannot determine both the speed/direction and position of anything, no matter how it's measured by definition of the measurement of speed/direction requiring more than one position. That's to say, I'm under the impression that the Heisenberg Uncertainty Principle has nothing to do with technology and will always be true under any conditions with any equipment in the areas where it applies, world without end, Amen. Am I wrong?

That is a combined 'yes' and 'no' answer.

Yes: Measuring exact values of electron is really hard. They don't even show up as precise values when we look at them, simply because they are so small and move so fast. We see that as a sort of 'smear'. (A Fourier transform.)

Heisenberg's equations for determining more precise values don't commute. (i.e. You cannot shuffle the variables around and still have it work.) This implies that it should be mathematically impossible to determine the velocity and position at the same instant.

No: Because all of the above is still based on the assumption that that our current method of measuring particles is all there is. If they could be measured more accurately or without adding energy to the system, the Uncertainty Principle should no longer be relevant.

Of course, science is pretty sure that's impossible. (Hell, they didn't even have that in Star Trek.) But we've proved ourselves wrong a lot of times in the past.

@soulmonarch (and of interest to @Payback too)

So, in a nutshell, as far as current science is concerned, the HUP is as valid as any other principle/theory/law, in that it's technically possible that some day, the future being what it is, it may be proven wrong. If that's the case, then I think saying it's merely a technological limitation in answer to Payback's query is misleading. The current scientific theory is indeed that it's impossible to measure both velocity and position, not, "We just don't have the right gear yet."