it's not so funny now.

And 92 is the atomic number of Uranium, not the atomic mass. Geez!

By 1910, 40 radioactive elements had been isolated that were associated with the process by which uranium metal decayed to lead-
http://chemed.chem.purdue.edu/genchem/topicreview/bp/ch23/history.php

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.

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.

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....

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.

How about a short follow-up on how hard it would be for a terrrist to make one of these?

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.

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)

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.

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.

Hurray for the double-edged sword of technology!