81–90 of 373 posts
What do you think about Topological Quantum Computation?
How do you think we can solve the problem that many people getting their PhD are vastly underpaid and also adjunct professors?
Can you explain to me the concept of "logical qubit", and the whole debacle about qubit quality? I'm still getting confused again and again over this.
What do you think of radical Mathematical Platonism (eg. a la Tegmark)? As a computational physicist I tend to tell people that in my hands a computer is like a telescope, but it lets me see into mathematics---but that seems to tacitly assume the reality of mathematical objects.
Do you believe there is now a quantum Moore's Law in place? I've seen graphs showing quantum chips from Google, IBM, and Intel plotted on a log scale that are suggestive. (These exclude adiabatic quantum computers which are different beasts.) If there is do you think we're perhaps less than 10 years from QC capable of breaking common number theory based asymmetric cryptographic algorithms like RSA or elliptic curve f…
Back of the envelope:
- It takes 9n error-corrected qubits to break an n-bit ECDH key [1]
- Each error-corrected qubit requires ~2500 physical qubits [2][3]
- Typical ECDH key size is 256 bits [4]
- This year would be the year of ~64 physical qubit machines. [5][6][7]
- log_2(256 * 9 * 2500 / 64) ~= 16.4 years
Note that every one of the quantities in the estimate is subject to future research. E.g. the error corrected qubit size is smaller when using lattice surgery, but not enough to really move the needle on the time estimate.
[1]: https://arxiv.org/abs/1706.06752
[2]: See section VI of https://arxiv.org/abs/1805.03662
[3]: https://docs.google.com/presentation/d/e/2PACX-1vReeRxH80Ruu...
[4]: https://crypto.stackexchange.com/a/47337/7860
[5]: https://ai.googleblog.com/2018/03/a-preview-of-bristlecone-g...
[6]: https://www-03.ibm.com/press/us/en/pressrelease/53374.wss
[7]: https://newsroom.intel.com/press-kits/quantum-computing/#49-...
Earlier quoted context omitted.
Algorithms 101
And beyond that?
You were said to be a skeptic of quantum computing company d wave. Then you started believing and then went back to skepticism. What is your current status, do you think it works? What would you like to see from them? Also, what is your take on Max Tegmark's quantum suicide experiment. Would it work? If yes would that imply that each of us should expect to live a really long time subjectively?
On a more sociological level, D-Wave earned a lot of bad blood with the academic QC community by making false, inflated, and overhyped claims (with a primary offender being its founder, Geordie Rose, who's since left the company). And I certainly took them to task for those sorts of things on my blog. Then the D-Wave folks met with me, John Preskill, and other academics, and pledged to improve in how they communicated, so I was nicer to them for a while. Then they went back to egregious hype about speedups that weren't real, so I criticized them again. Nothing more to it than that. :-)
Regarding quantum suicide: no, I do NOT recommend killing yourself any time anything happens in your life that makes you unhappy, on the theory that other versions of you will survive, in other branches of the quantum-mechanical wavefunction where the bad event didn't happen. This is partly because, even assuming you accept the Many-Worlds Interpretation, "your" moral concern and responsibility presumably extend only to those branches that are in "your" future -- you have no contact with the other branches! And partly it's because I take it as almost an axiom of rationality that, if a metaphysical belief leads you to do "obviously insane" things with your life, then it's probably time to look for a better metaphysical belief. :-) (I wouldn't say the same about scientific or mathematical beliefs.)
Hi Scott, If quantum computing ever becomes commonplace, and quantum computer programs widely written and understood, do you envision that the teaching of quantum mechanics itself will be significantly impacted? Or instead will we simply see quantum complexity theory begin to redefine the undergraduate computer science curriculum?
Why is P=NP/P!=NP so difficult to prove? I just wanted to say that I think your writing helped me appreciate Michael Cohen and learn what an amazing person he was. The more I read about him, the more I want to be like him. What qualities do you think helped him contribute and be such a great person? What do you think a lackluster programmer could do to be more like him?