uvdiv

61 ms·

511.
by uvdiv 15y ago
E.g. * Annual impact -- 5-20 kt (~Hiroshima) * Indonesia superbolide (2009) -- 50 kt * Tunguska (Siberia 1908) -- 10-15 Mt (~large hydrogen bomb) * K-T extinction (65 MYA) -- 10^14 t = 100,000,000 Mt (complete detonation of ~2 million tons
512.
by uvdiv 15y ago
"do traditional desalination techniques require more energy than boiling the equivalent amount of water?" No, far less, because the end product is condensed liquid water (not vapor). When* the desalination method is distillation (evaporatin
513.
by uvdiv 15y ago
No, results specific to solar panel orientation. Math is not trivial at all, but the results are intuitive: roughly, point the panel in the direction which, in mean, is in the direction of the sun. So tilted towards the equator, at the same
514.
by uvdiv 15y ago
That's not actually sufficient to show unique extrema; there an be a set of points on which a function achieves the same, maximal, value. i.e. cos(x) over x <- [0,4π] -- multiple maxima at {0,2π,4π}. But we don't really need unique ex
515.
by uvdiv 15y ago
Crucial difference: the tree-leaf problem is about how to arrange leaves which are shading each other; but here he compares such a "tree" with a flat array that has no overlaps at all . He claims that the tree generates more energy than th
516.
by uvdiv 15y ago
"Basically the tree of cells are arranged in different angles so that as the sun moves some of them will always be receiving optimal sunlight when their normal is parallel with that of the incident light." Except it's trivially impossible
517.
by uvdiv 15y ago
So in essence they are retaliating for having their credit score lowered. What kind of system is this, where the rating agency financially benefits from giving municipalities safe ratings? Is this legal (on the part of the munis)?
518.
by uvdiv 15y ago
For an auto engine it is beyond hopeless (economics, safety). This particular case is a crackpot/scammer with no substance at all. Very small nuclear-powered engines are possible. There were several launched on space satellites by the US an
519.
by uvdiv 15y ago
It's a blatant scam, it doesn't work. No one's building nuclear auto engines.
520.
by uvdiv 15y ago
They're a row of elements on the periodic table (lanthanides) which have a broad range of industrial uses (see the wiki). It is a misnomer, as many of them aren't particularly rare. http://en.wikipedia.org/wiki/Lanthanide http://en.wiki
521.
by uvdiv 15y ago
It's a novelty item, the point is it makes it easy to find in the dark: http://unitednuclear.com/index.php?main_page=product_info&#3... Seems benign to me, since beta radiation won't penetrate the glass. See also http://en.wikipedia.org/
522.
by uvdiv 15y ago
LA residents are sitting next to an ocean. If they want water, they should elect a government that will allow them to build desalination plants, as opposed to one which creates artificial scarcity.
523.
by uvdiv 15y ago
I'm sure I'm ignorant about NASA research, but I don't understand your criticism. NASA projects are very much directed by politicians: i.e. the James Webb cancellation was caused by Congress, not NAS policy. "US lawmakers vote to kill Hubbl
524.
by uvdiv 15y ago
...there must be an economic reason to make the trip. Solve that problem... Isn't that backwards? If moon travel is not economically worth it, that's not a "problem", that's objective reality. And if you try to invent/force an economic "r
525.
by uvdiv 15y ago
No, it's extremely funny but it's true. The Ph.D. student at the time left research after receiving his degree and now works as an analyst for an international bank. http://news.sciencemag.org/scienceinsider/2009/09/fake-data-... The S
526.
by uvdiv 15y ago
This reminds me of a case in Europe, where a PhD chemist was found to have faked/fabricated large parts of his graduate work, including his thesis. (It was on Derek Lowe's blog, pipeline.corante.com, and other places). He used Switzerland's
527.
by uvdiv 15y ago
It's sobering to think, nothing the entire private space industry put together has proposed comes close to what NASA was sitting on in the 1960's, with nuclear pulse propulsion. Now it's unthinkable. But with a slightly different historical
528.
by uvdiv 15y ago
Science research is one thing the private sector does poorly, and it's something NASA does a lot of. Yes, but... NASA does very little space science compared to non-scientific human space travel. Their budget for launching humans into spa
529.
by uvdiv 15y ago
That looks more like a feature of private/competing currencies than commodity currencies. If a commodity money is backed by a state, it shouldn't act differently from fiat money (assuming its price is stable enough to act as a useful "unit
530.
by uvdiv 15y ago
Isn't all of its debt dollar-denominated? edit: Now that I think about, it isn't. They have inflation-indexed bonds as well. The more they print money, they bigger their debt grows! http://www.treasurydirect.gov/indiv/products/prod_tips_gl
531.
by uvdiv 15y ago
"Newsflash: countries have armies..." All the Red horses and all the Red men could not put Soviet economy together again.
532.
by uvdiv 15y ago
Yes, commodity money. A commodity has intrinsic value; so if you use commodities as money (medium of exchange, store of value...), you have money with intrinsic worth. Supposedly it's the original money, since it arises spontaneously in a b
533.
by uvdiv 15y ago
I hope you do not seriously believe that the reason gold is not used for trade is that governments suppress it. Exchange of gold is subject to capital gains tax; exchange of the US dollar is not. It is clearly suppressed as a currency. (A
534.
by uvdiv 15y ago
Debt is a mechanism for moving risk around Much more fundamentally, it is a mechanism for moving things around -- tangible capital like tools and buildings. Interest is in part a payment for risk of default, but it is also payment for
535.
by uvdiv 15y ago
The fact is it takes a long time to decide how safe something is, especially on the roads. For each month this technology's market deployment is delayed, there's a 9/11 of American deaths in car accidents. Even if Google went ahead with m
536.
by uvdiv 15y ago
There's also the fact that the plasma has extremely low density, so there is very little fuel in the core at a time: "Less than 1g of fusion fuel is present in the Vacuum Vessel at any one moment." http://www.iter.org/mach/fuelcycle
537.
by uvdiv 15y ago
The photosphere does not produce power, so attempts to calculate volumetric energy densities there are nonsensical. The power radiated from 1 square meter of the sun's surface (63 megawatts) comes from a cross section of the core, far below
538.
by uvdiv 15y ago
Or the "fuel from seawater" thing. Seawater contains 3.3 ppb of uranium, and it would be commercially feasible to extract it if the prices were higher. ... And you can use more advanced fission cycles, especially the thorium ones, to exten
539.
by uvdiv 15y ago
yaakov34 is talking about power density, not energy density. The sun's core power density only about 0.3 watts/liter, compared with >100,000 W/L for a power-generating nuclear fission reactor. http://en.wikipedia.org/wiki/Sun#Core
540.
by uvdiv 15y ago
How would the director of the Princeton Plasma Physics Laboratory benefit from that?

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