ARSTechnica on how quantum computers work

[thilanliyan]

http://arstechnica.com/science/guides/2010/01/a-tale-of-two-qubits-how-quantum-computers-work.ars

 

[Rhoxed]

Great read, thanks thilanliyan!

 

[ScorcherDarkly]

Yes, thank you for reminding me of the nightmares of bra-ket notation. This article needs to come stamped with a warning to wait until morning before starting to read it.

 

[silverpig]

Loved it

 

[jimhsu]

Um.. Erm. Let me wait a while before seriously trying to read that. It's been a while since I last took QM ... like 2 years ago?

 

[Fox5]

Wow, I still don't understand quantum theory. I trust it as a statistical theory formed around real data, but it'd be nice to have some answers about what's really going on.

BTW, when they talk about entangled photons, how do they measure individual photons? You can't transmit a single photon, you transmit a beam of photons, and how would you ever know which is entangled or not?

 

[jimhsu]

Wow, I still don't understand quantum theory. I trust it as a statistical theory formed around real data, but it'd be nice to have some answers about what's really going on.

BTW, when they talk about entangled photons, how do they measure individual photons? You can't transmit a single photon, you transmit a beam of photons, and how would you ever know which is entangled or not?

Of course, "I think I can safely say that nobody understands quantum mechanics."
~Richard Feynman, in The Character of Physical Law (1965)

The thing is everything that we understand has to be statistical. There's basically no way to "see" what is going on (i.e. Heisenberg's uncertainty principle, etc). Only "this can be explained by quantum mechanics", not "this IS quantum mechanics".

 

[Fox5]

Of course, "I think I can safely say that nobody understands quantum mechanics."
~Richard Feynman, in The Character of Physical Law (1965)

The thing is everything that we understand has to be statistical. There's basically no way to "see" what is going on (i.e. Heisenberg's uncertainty principle, etc). Only "this can be explained by quantum mechanics", not "this IS quantum mechanics".

Yeah, but it seems that so many of the crazier interpretations of what quantum mechanics can do are based on "this is quantum mechanics" without setting bounds and limits on it. It just feels like the theory guys are getting ahead of the experimental guys by too much. I guess that's what theorists are for tho.

 

[Avalon]

Was a good read while I was drinking last night.

 

[jimhsu]

Yeah, but it seems that so many of the crazier interpretations of what quantum mechanics can do are based on "this is quantum mechanics" without setting bounds and limits on it. It just feels like the theory guys are getting ahead of the experimental guys by too much. I guess that's what theorists are for tho.

And pure mathematicians are ahead of everyone else by at least 50 years, probably a century. Just saying...
(note /me is not a mathematician)

 

[f4phantom2500]

Wow, I still don't understand quantum theory. I trust it as a statistical theory formed around real data, but it'd be nice to have some answers about what's really going on.

BTW, when they talk about entangled photons, how do they measure individual photons? You can't transmit a single photon, you transmit a beam of photons, and how would you ever know which is entangled or not?

http://www.ted.com/talks/lang/eng/brian_greene_on_string_theory.html

that might help.

 

[jimhsu]

http://www.ted.com/talks/lang/eng/brian_greene_on_string_theory.html

that might help.

The first words of the talk: "In the year 1919, a virtually unknown German mathematician" ...

Proving my point.

EDIT: Great talk though regardless of whether or not you agree with string theory.