evanb

39 ms·

481.
by evanb 6y ago
Dirac used to introduce her as "Wigner's sister" rather than "my wife".
482.
by evanb 6y ago
I mean National Park in exactly the same way that everybody means National Park: Rock Creek Park was the third National Park, made so by an Act of Congress, just like any other big-N National big-P Park. https://www.loc.gov&#x2F
483.
by evanb 6y ago
Rock Creek Park is a National Park. https://www.nps.gov/rocr/index.htm
484.
by evanb 6y ago
You might expect two alphas to make 8Be and then another alpha to make 12C, but 8Be is unstable on a very short timescale 10^-16 seconds. Amazingly, 12C has a resonance called the Hoyle State that allows a triple alpha to 12C process. The
485.
by evanb 6y ago
Bias here means reliably off in a particular direction, not discriminatory. “That statistical estimator has a bias” means that you can expect it to often produce an over estimate (for example).
486.
by evanb 6y ago
Making the maze longer by just one rule increases the number of indents by four. But, for his calculation the number of indents in the hindrance (it is valid to do it as a function of the number of tiles, instead, of you want) but the conv
487.
“Real” Programmers and Drum Memory – Computerphile [video](youtu.be)
2 points by evanb 6y ago|0 comments
488.
by evanb 6y ago
You're right---I forgot the protocol. Thanks for the correction!
489.
by evanb 6y ago
In superdense coding you send one quantum bit ahead of time and hang onto it’s entangled partner. Then later you send one classical but which, when combined with the quantum bit you shared earlier, conveys two classical bits of your choice
490.
by evanb 6y ago
Discretionary time is usually given to projects which otherwise didn't get any time, it's not usually hoarded for the director himself.
491.
by evanb 6y ago
If the two choices are "costco serves me" and "costco is worldwide", the latter is much closer to the truth.
492.
Japan top court tells Twitter to disclose retweeters' info(japantimes.co.jp)
119 points by evanb 6y ago|100 comments
493.
by evanb 6y ago
By the time I saw it the replies were closed, unfortunately.
494.
by evanb 6y ago
:wave: https://news.ycombinator.com/item?id=11813473 Still not going to install anything Java, but I hope my comments were helpful!
495.
by evanb 6y ago
It's not the fluctuations, but the zero-point energy. In a supersymmetric theory the number exactly cancels. If the Standard Model is some low-energy EFT of a supersymmetric theory, it could be almost-0.
496.
by evanb 6y ago
A "sector" of the Standard Model---like the QCD sector, or the electroweak sector, or the Higgs sector---is just shorthand for a part of the the Standard Model that consists of particles and forces. It's possible that dark ma
497.
by evanb 6y ago
In the Standard Model as written in the 1970s the neutrinos had to be exactly massless. We now have evidence that neutrinos aren't exactly massless, but they're very VERY light. Like, absurdly light. We still don't know th
498.
by evanb 6y ago
This ignores the enormous logistical difficulties associated with, say, timezones. If my online classes are at 2 AM but the grocery store is only open from 9-5, I am going to be exhausted all semester.
499.
by evanb 6y ago
The regulations explicitly mention and close this loophole. To count as in-person it can't just be for people who need help with their visa, and attendance can't be optional or sporadic.
500.
by evanb 6y ago
If the wavefunction is supposed to have n,l,m quantum numbers (as suggested by the interface) then yes, it should be rotationally symmetric around the z axis.
501.
by evanb 6y ago
I took this course during a January term. It was great fun and Sanjoy was a great teacher, with tons of energy and enthusiasm.
502.
by evanb 6y ago
You may feel that way but the NRA has a history of caring who has the arms. See, for example, 1967's Black Panthers https://www.snopes.com/fact-check/nra-california-open-carry-...
503.
by evanb 6y ago
I use 1pw 7 and don't pay for a subscription.
504.
by evanb 6y ago
I _am_ a computational physicist. The main problem I'm interested in is of a slightly different nature: just compute properties of protons, neutrons, and light nuclei from QCD, the theory of quarks and gluons. However, because the &q
505.
by evanb 6y ago
Stationary means a blackhole that is not evolving in time---one that is in a stationary state https://en.wikipedia.org/wiki/Stationary_state Note that the article focuses on the QM meaning of stationary, but there&#x2
506.
by evanb 6y ago
QCD is a nonabelian gauge theory, for example. The generalized Maxwell action is called the Yang-Mills action. The corresponding equations are very similar, except the gauge-covariant derivatives do not take a particularly simple form (wh
507.
by evanb 6y ago
Well, if you took a little bar magnet and shot it through it'd go around one time.
508.
by evanb 6y ago
I was trying to convey that "Maxwell's equations" can name not just the equations that describe electromagnetism, which has a U(1) gauge group, but can name an entire category of gauge theory equations---one for each gauge gr
509.
by evanb 6y ago
Yes. If you take an electron beam, put it through an [electron] beam splitter, put half through a magnetic field that would spin the electron around once, and recombine the beams you will see interference effects.
510.
by evanb 6y ago
Posse Commitatus prevents the military from performing law-enforcement duties. The _governor_ can activate the national guard for cases like this.

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