Scinter me timbers!
Solutions:
A) outlaw moon exploration
B) outlaw rats
C) outlaw the name Nel for all people who are sisters
Simples
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Nuclear weapons are 239Pu whereas the radio thermal generators need 238Pu. We should dismantle nuclear bombs because itâs insane to have an automated system for ending human life on earth. Maybe we could claim that dismantling all nuclear weapons would help us make satellites and hope the politicians donât cotton on.
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The alpha radiation from plutonium is not penetrating. Itâs easy to screen the radiation from plutonium with a thin layer of nickel plating (etc), through which the heat can still get out. To screen the radiation from Cobalt-60 or Strontium-90 you need a more substantial shield (block of lead) which puts the mass up and makes the satellite inefficient to launch.
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I love the Mash. Itâs my main news source. No, really.
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Indeed. More than once Iâve only become aware of a news story after seeing the Mashâs take on it.
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Clearly, Ferguson would never have happened if we had never gone into space. And bigotry and violence will never be solved while we are still there.
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Well, we went to North America in 1492, and 50 decades later we still have Ferguson. Looks like we arenât capable of both.
Well, we left Africa 70,000 years ago, and 7,000 decades later we still have Ferguson. Looks like we arenât capable of both.
Well, we developed as anatomically modern humans 200,000 years ago, and 20,000 decades later we still have Ferguson. Looks like we arenât capable of both.
Well, we developed cells with a nucleus 2,100 million years ago, and 210,000,000 decades later we still have Ferguson. Looks like we arenât capable of both.
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Just SUBTRACT ONE.
All this new math has people in a tizzy. Good olâ fashioned math TO THE RESCUE.
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Yes. It just happens that it has multiple isotopes with wildly different properties and uses.
Elements differ in electron configuration. Their uses depend on their chemical properties.
Isotopes differ in nuclear configuration. Their uses depend on their nuclear properties.
There is even a weak overlap of nuclear to chemical properties; heavier atoms are lazier to react (and evaporate, and generally behave), so the reaction products will tend to be slightly enriched with the lighter elements and distillation remains with the heavier ones. This can be exploited in isotopic signatures; you can find who eats diet rich on C3 or C4 plants, or who is a vegetarian and who is not - even in archaeologic materials. And the isotope effects can be quite significant, so e.g. certain high-precision measurements in semiconductor research are done in isotopically purified silicon.
Thatâs known as (n,2n) reaction. But its cross-section for Pu-239 is woefully low for industrial use.
Sadly, there does not seem to be a better cooling system for bellicose politico hotheads. Better keep 'em in place; for all its insanity present even in its own name, the MAD doctrine worked. At least with the Russkies.
Nice! How could I miss this news?
Bombs use only the 239 kind. The 241 kind is an impurity (bred from Pu-240, which is the major impurity), which is a royal pest because it beta-decays to americium-241 (I think the element names are not capitalized!), and that one has unpleasant and fairly penetrating gamma radiation that complicates logistics and handling (so older pits are gradually becoming âhotterâ). It used to be separated on reprocessing of aged plutonium pits, where the buildup was significant, but the Rocky Flats plant later skipped this step for financial reasons, trading money for workersâ dose equivalent.
The weapon-grade plutonium is specified to have low amount of the other isotopes. The âsupergradeâ is a sub-spec with even lower amount, especially of the Pu-241/Am-241 ones, in order to lower the radiation levels; usually specified for pits that were supposed to be close to people for prolonged times, e.g. in nuclear submarines.
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I guess we can only use Pu-238. Because apparently thatâs the final, hard-coded limit of all human inventiveness and imagination. We canât do any more new things, previously unknown to Internet forums, because Reasons. And if you donât agree you are not Science.
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âBombs use only the 239 kind. The 241 kind is an impurity (bred from
Pu-240, which is the major impurity), which is a royal pest because it
beta-decays to americium-241â
Thank you! I spent five minutes before posting my comment trying to figure out if there was a difference between the two as far as bomb making goes and got nowhere (Wikipedia often loses the most relevant information under vast piles of nerdy trivia). Must. upgrade. Google. Skilz.
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The MER rovers (Opportunity and Spirit) use solar cells. Oppy is still going after nearly 11 years on the surface, but itâs been very touch and go at times. Dust deposition is huge problem, partly offset by the occasional whirlwind which clean off months of dust accumulation in seconds.
Nevertheless, managing the power budget is a constant problem - weeks long dust storms nearly killed the rovers, and the only way to deal with winter is to find a slope that faces the panels into the sun, and hunker down, immobile, for 6 months at time.
the only way to deal with winter is to find a slope that faces the
panels into the sun, and hunker down, immobile, for 6 months at time.
Hey, thatâs how I survive winters here in Norway!
âŚonly, they last 37 months per year:(
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From last year
It appears to this occasionally paranoid writer that the only purpose of this plan, if indeed it was conceived with a purpose in mind, is to largely shut down NASAâs Planetary Science Division by preventing it from carrying out a sustainable launch program. It does seem clear that, intended or not, this is likely to be the effect.
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God fucking damn it. Why mess up a good thing? Itâs like they donât like space, or something.
Sadly, atomic physics places limits on human inventiveness.
There are all kinds of ways to power a spacecraft. But for missions that last a decade or longer, for missions to the outer solar system where solar power is not an option, your only choice is some kind of nuclear power.
There are all kinds of nuclear power. But for a deep space probe, with strict mass limits and no ability to sent out a repair tech when things go wrong, youâve got to depend on natural radioactive decay, not fission.
Wikipedia has a helpful list of criteria for selecting the right isotope. Basically, you need something that emits lots of alpha particles (easy to shield and produces lots of heat) and not much of anything else. It needs to have a half life of decades or longer, and for a space probe, it needs to provide lots of energy per kilogram so it can be lightweight. Plutonium 238 is the best match for all these criteria.
There are (a very few) other isotopes that could fill the bill, but NASA already knows how to build Pu-238 RTGs. So thereâs a lot of infrastructural and institutional inertia that is preventing them from switching to any other options.
The ESA doesnât have that inertia, so theyâve been working on perfecting Americium based RTGs.
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" I guess we can only use Pu-238. Because apparently thatâs the final, hard-coded limit of all human inventiveness and imagination. We canât do any more new things, previously unknown to Internet forums, because Reasons. And if you donât agree you are not Science."
There are only 80 distinct elements which have at least one stable isotope, and another ten or so which have an isotope with a sufficiently long half life to make a RTG. The result is that just about all the isotopes of the possible elements have been explored in enough detail for the feasibility of any possible RTGs to be established. As for the supposed âisland of stabilityâ, even if it exists there are no processes available to reach it with any kind of significant yield.
Sometimes, as with the speed of light, the Universe says âne plus ultraâ very firmly indeed.
Well, so what if we can only use Pu-238? We can make more 
Every bit weâve used so far is stuff weâve made. Itâs not a naturally occurring element, but weâve been synthesizing it since 1941.
The problem is not because Science.
The problem is because Funding.
We need to convince more than half of the Congress Critters that funding this improves their personal chances for re-election, because really, thatâs the only thing in the universe that matters to them.
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