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visits member for 3 years, 6 months
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Aug
14
comment When a star becomes a black hole, does its gravitational field strength become stronger?
This applies once the ejecta pass the planet's orbit, right?
Aug
3
awarded  Commentator
Aug
3
comment Forces other than the fundamental interactions, e.g. friction
Nice answer. Any suggestions on where I could learn more (at a fairly basic level) about the $r^{-6}$ interaction? (E.g., why is the next term not $r^{-4}$?)
Jul
2
awarded  Curious
Jun
27
comment Are galaxies “disk” shaped?
We often see them edge-on, so we have a pretty good idea of what general galaxies' z-axes look like.
Mar
21
awarded  Citizen Patrol
Oct
23
comment Surface gravity for a rotating charged black hole
Thanks, that's just what I was looking for! (I'll upvote as soon as I can -- not able to right now.)
Oct
23
awarded  Yearling
Oct
23
accepted Surface gravity for a rotating charged black hole
Oct
23
revised Surface gravity for a rotating charged black hole
not actually homework, just personal interest -- in fact I've never taken a class on this, as may be evident from my lack of sophistication
Oct
22
asked Surface gravity for a rotating charged black hole
Jun
20
comment How many qubits are needed for useful computation?
And Seifert says it can be done in $(1+\varepsilon)\log n$ qubits. I don't know the size of the implicit error term but this could lower the threshold to 700 or so.
Jun
20
comment How many qubits are needed for useful computation?
Zalka gives a version of Shor's algorithm requiring only $\lceil 1.5\log n\rceil+2$ qubits, so 1000 qubits is a good threshold for doing useful factoring.
Jun
13
comment Limits of superdense coding
Thank you! I will try to read the papers now.
Jun
13
accepted Limits of superdense coding
Jun
13
comment Limits of superdense coding
Since I'm new to quantum information theory, would you define your terms? In particular, what are A, B, S, and $\rho$? I notice that you never used my N, so would you verify that having N > n entangled qubits does not allow more than 2n bits to be received? (This seems to follow from the no-communication theorem, but I'd like confirmation.)
Jun
12
asked Limits of superdense coding
Oct
22
accepted Why can't a stable star have radius 1 < r < 9/8 its Schwarzschild radius?
Dec
22
accepted Optimality of the CHSH strategy
Dec
10
comment Why can't a stable star have radius 1 < r < 9/8 its Schwarzschild radius?
@dmckee: Perhaps, but 9/8 isn't that close to 3/2, so something else would have to be at work as well.