For our group meetings, we used to do chalkboard talks, and this year we ended them for all the same reasons. Without slides, the discussion tends to wander aimlessly, and the speaker does not get to talk about what she intended to talk about in the first place. It takes forever to sketch the simplest diagrams on a chalkboard, the resulting figure has little accuracy and the audience has to sit through a lot of pointless sketching where no information is being conveyed.
Most people still use LaTeX-Beamer rather than PowerPoint, but the latest versions of PPT actually have very good equation tools, so IMHO, there's little reason to favor one over the other. The days of academics trashing on PPT are long gone.
"MAYBE THERE'S JUST ONE ELECTRON!" Feynman once shouted.
Actually, that's basically right. Our current understanding (in quantum field theory) is that there's only one electron field, and all electrons and positrons are quantum excitations of that field. It's a bit more complicated, in that there are actually four electron fields, which cover left-handed/right-handed and electron/positron degrees of freedom. But if you think of those four fields as being the "one" electron, the idea works perfectly.
If you were to write a simple python program that uses say, the Panda package, would you include all the lines of code of that package when line counting your program? No.
Yes, as we all know, Hello World in C is actually thousands of lines long. (shakes head sadly) It's a terrible language.
b) it is opaque, in the sense that there is little control on what code is doing what data: many of the functions act actually as black boxes and it is not straightforward to see how to actually get in control of the system and/or understand what is actually being done in order to provide an answer.
You can usually twiddle all the options in a function; the documentation is pretty good for most of the standard libraries. Of course, the demo doesn't look as slick if you have to use 6 lines of optional parameters to get the exact thing you want. Typically, the default options do a pretty good job, and there's a lot less typing for those cases.
Of course, it's also a universal language. You don't have to use the standard libraries; feel free to roll your own. I'm sure an hour later, you'll have a bit more respect for how well the default stuff works.
The hacking attack is detailed in a leaked “crisis strategy draft” plan, apparently created by Gox and published Monday by Ryan Selkis, a bitcoin entrepreneur and blogger (see below). According to the document, the exchange is insolvent after losing 744,408 bitcoins — worth about $350 million at Monday’s trading prices."
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If the spin of the particle (electron in the summary) is germaine to the observed properties of the particle does that mean there are two different particles involved?
Yes! And there always has been. Left-handed particles are not the same as right-handed ones. Quarks in particular come in a dizzying amount of varieties. There are 6 flavors times 3 colors times 2 spins times 2 for regular/anti. So in total there are actually 72 kinds of quark!
But people find it easier to talk about there being fewer kinds and specifying the exact types only as necessary. That makes sense, because particles of one type can change into particles of another type pretty easily. For example, you could have a quark in a superposition of left- and right-handed states. Quarks are constantly changing their color as they exchange gluons with other quarks inside the proton. Flavor and regular/anti change the least, so you generally hear people talk about a "strange quark" or a "top antiquark". But all those other properties are always around.
I'm not sure what difference this makes to the actual habitability of the planets, but all of these are tidally locked. That is, the same part of the planet is always facing the star (and thus baked) while the same part faces empty space (and thus freezes). A thick atmosphere might transport heat and make things more uniform, but none of these are what one would naively think of as "habitable". In fact, all planets in the "habitable" zone of such small stars are going to be tidally locked. Wikipedia actually has a nice summary of the problem of tidal locking in small stars.
On the other hand, they might have very interesting moons.
There's no real way to "confirm" the number of quarks. Quark number is not a conserved quantum number, so every particle exists as a superposition of different quark numbers. This is particularly problematic if you probe a particle at very high energies; at sufficiently high energies, every hadron (including the humble proton) appears to be a soup of quark-antiquark pairs bubbling out of the vacuum. However, you should be able to make predictions of what the particle's properties will be if it's mostly like a particle that has 4 quarks (really 2 quarks and 2 antiquarks) versus if it's mostly like a particle that is 2 loosely bound mesons (1 quark and 1 antiquark plus 1 quark and 1 antiquark). But there's no definitive way to distinguish between the two.
It's also noteworthy that neither tetraquarks nor mesonic molecules have been previously seen in two experiments. So no matter which it turns out to be mostly like, it's still a discovery.
Anyone interested in the D-wave story should be reading this article where Scott Aaronson explains the meaning of D-Wave's current results.
The takeaway points are:
- D-Wave's machine does demonstrate entanglement and quantum annealing
- There is no speed advantage whatsoever for quantum annealing over classical simulated annealing
- A correctly optimized version of classical annealing is actually faster than D-wave's solution
- D-Wave will only be able to make this machine work as a quantum computer (with the attendant speed gains) by implementing error-correction and other improvements that D-Wave have been loudly deriding for their entire history
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