I think I need a long bath.
Thanks for brightening my day man. Jesus!
Humans are so awesome, aren't we?
this would be a nice snark, but i _just_ left this website: http://faculty.ucmerced.edu/smalloy/atomic_tragedy/photos.html
it's not so funny now.
It's not the XML parser that's evil, it's XML itself.
And 92 is the atomic number of Uranium, not the atomic mass. Geez!
I think you meant lead (82) not iron. Uranium, and pretty much all the other elements above lead decay to lead eventually.
By 1910, 40 radioactive elements had been isolated that were associated with the process by which uranium metal decayed to lead-
So all the elements bigger than lead DO want to be lead, but lead, and all the elements below it, just want to be themselves.
Ack, w7ngman. You're correct (about both XML and the atomic mass/number.) Fixed (to atomic number.)
I knew it, but didn't write it.
This is a common misconception. Lead is indeed the stable element at the bottom of many fission decay chains. But Iron is the element with the highest nuclear binding energy.
You can worry all you want about aluminum tubes and alleged attempts to build centrifuges to develop weapons-grade nuclear fuel, it's the thousands of so-called "theater" nukes designed to protect (or invade - depending who had em) Western Europe that keep me up at night.
All it takes is one or two of those in a container at the Port of Seattle, and every one of us will have a day that gets much, much brighter, and then very very dark, indeed....
#8 I appreciate these follow-ups. I thought it was lead too.
I just read that link... I'd love to go walk on a dead, iron star. I'm guessing I'd get smushed on the surface though.
The Ivy Mike was true insanity. It was as large as an aircraft hangar. Yes, one bomb. The resulting explosion literally wiped the island it was built on (Elugelab Island in the Enewetak Atoll) off the face of the earth.
Oh god. Am I the only one who thinks there's about a zero chance we won't see one of these used to kill in our lifetimes?
How about a short follow-up on how hard it would be for a terrrist to make one of these?
This afternoon, I just heard a scientific talk about diverting asteroids on a collision course with the earth with nuclear weapons. The best case would be to push on it enough so that after a couple of orbits it would miss. But if you had to and it far enough out such that most of the debris would miss, you can just blow it up with a ~10 Mt bomb.
But no, you don't need Bruce Willis to go drill a hole.
You're totally right, of course. In November, I slogged that very point--that nuclear weapons are more a demonstration of industrial prowess than an actual weapon.
I still believe the only people to be irradiated by, say, an Iranian bomb will be the Iranians manufacturing the damn things.
And I'll restate another point: Biological weapons remain the most promising technology for a suicidal terrorist group.
Hey, Jon, since I'm drunk and you're not, help me out here: somewhere, somewhen back before you were born, I seem to remember reading that the basis of a supernova was an iron-fusion reaction. Am I remembering this correctly, or just drunk?
Regardless, at least give me some credit for not making any bad jokes about ferrous wheels.
Ameeeerica, Fuck Yeah! Coming up to here to save the motherfucking day, yeah
Fifty Two Eighty:
You are correct. At high enough temperature and pressure, any nucleus lower than iron will combine to make iron and give off energy (after that, they will still combine, but will lose energy). After exhausting hydrogen fuel, a big enough star will then burn its helium, then go up through boron, carbon, oxygen, neon, etc. until it either blows itself apart (switching fuels isn't easy, as the star collapses until the necessary pressure / temperature is reached, blowing of a fair amount of material in the process), or just doesn't get hot enough.
In the end, after saving itself by burning everything, it's left with iron combining into heavier elements and soaking up energy.
One common alternative is when a star gets almost to the iron-burning stage, but not quite. If it then arranges to pick up material slowly (as from an orbiting companion star), it will eventually go over the mass limit, and start making iron, blowing up in the process. This is a type II supernova. We can occasionally see these puppies blow up, and then watch them cool off / lose brightness. The nifty thing is, the way they lose brightness confirms that the end result is iron. The half life of the brightness is the same as the half life of an isotope as it decays to iron (don't have the source for which it is, sorry).
It all works out, and it's nifty.
(MS., astrophysics, many years ago)
Thank you, Jon.
You don't like Castle Bravo? The largest above-ground US nuclear test! The origin of the concept of the 'unexpected fission surplus'.... rather than use a lead tamper around the 'sparkplug', they used U-238. The neutron flux from the fusion reacton caused the U-238 to (AFAIK) turn into Pu239 then quickly fission. (this is what I recall; I may be slightly off) It ended up bigger, and way more fallout-y than anyone expected.
Any list that omits the W88 is immediately suspect.
What about the Death Star???
You missed the point of the neutron bomb - not so much to leave the cities and whatnot, but that for a "regular" bomb at a decent distance a buttoned up tank (and the crew inside it) won't be all that effected by the concussive overpressure of the blast.
Sure the crew dies of radiation poisoning eventually, but that might take weeks. And by then the 37th Guards Motor Infantry are doing wheelies in Paris.
But the neutron bomb gives off a whole lot MORE radiation, so that the crew gets cooked inside their can. The tank (and as a handy side result, city) gets hit by less of a blast, but that wouldn't have destroyed it in the first place.
I'll grant you, Ivy Mike was impressive as a demonstration of the tech, but from a deployment standpoint the Mk-41 might be a better fit for that slot.
At 25 Mt yield, it was the largest production model thermonuclear device ever put into service, as well as being the only 3 stage TN device ever deployed by the U.S.
Plus, we built a shit-ton of 'em, around 500 all-told, and they also probably stayed in active stockpile longer that just about any other nuclear warhead or bomb built.
Re. neutron bombs vs. modern armour: Nowadays the M-1 Abrams tank uses slabs of depleted uranium in its armour plating. The stuff is superdense and works great against kinetic projectiles and such, but secondary cascade neutron reactions mean that the crew of an M-1 is vulnerable to neutron weapons at about twice the distance of the crew of a tank without DPU armour.
Hurray for the double-edged sword of technology!
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