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Comment by platz | Hacker News Reader

This is the "traversable" part: throw a qubit into black hole A. Measure a particle of its Hawking radiation & transmit the result of the measurement through the external universe to the other black hole B; then use this knowledge to operate on a Hawking particle coming out of black hole B to "reconstruct" the original qubit.

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This article was an interesting read even though I know close to nothing about quantum mechanics. The part you highlight made me think of Diffie-Hellman key change.

Silly but looking at the "octopus" it's like Hawking radition is SSH connections to the inside of the black hole :-)

I feel like if I were a pop science writer I would spin this more as a "teleportation" story.

You forget the part where the wormholes need to be prepared. First you need to feed the hawking radiation from one black hole into another.

> throw a qubit into black hole A

This would take infinite time (from the POV of the external observer), so I'm unclear how this is supposed to work.

Only in strict GR - when quantum effects are taken into account, the entire black hole will evaporate into Hawking radiation in a finite time.

> Only in strict GR

Even in strict GR, the statement is not correct. See my response upthread.

> This would take infinite time (from the POV of the external observer)

No, that's not correct. What is correct is that, in the idealized case where the hole is eternal (i.e., it never evaporates), it would take an infinite time for the external observer to see the qubit cross the horizon. But the qubit reaches the horizon and crosses it in a finite time.

But we are talking about an external observer - so how is this traversable plan going to work?

It's not, because this is all theoretical. Not a single thing here has ever been proven experimentally. Black holes do not exist, nor does hawking radiation.

[citation needed]

There's no direct proof yet, but we have detected the magnetic fields that theories predict, and of course observe the gravitational effects. The Event Horizon Telescope[0] will probably deliver something more tangible by 2018. [0]http://www.nature.com/news/how-to-hunt-for-a-black-hole-with...

> pov

so, light. which is not the medium used.

I known nothing of quatum shrnanigans, but I am thinking that in terms of protocols :)

Which is a good way to do it. QM is basically the most general protocol possible and most of the math can be derived from assumptions about what can in principle be communicated. For example:

http://www.mdpi.com/1099-4300/19/3/98/htm

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