Ok, I LOVE Roger Waters, but let's be fair here: Roger Waters's reply to literally everything is "FUCK YOU!". He's said FUCK YOU to David Gilmour so many times that last two remnants of the universe will be a single atom of Bismuth-209 and the last iota of Roger Waters's rage.

All I can think is Wood's Metal.
But I'd think he's know that.

Wood's metal, also known as Lipowitz's alloy or by the commercial names Cerrobend, Bendalloy, Pewtalloy and MCP 158, is a eutectic, fusible alloy with a melting point of approximately 70 °C (158 °F). It is a eutectic alloy of 50% bismuth, 26.7% lead, 13.3% tin, and 10% cadmium by weight.

They failed to mention bismuth as a gay element. Come ON, people! Pepto Bismol is PINK! From the PINK BISMUTH, bitchez!

You're all part of the homosexual agenda, aren't you?

I disagree with the notion that its arrogant to 'mess around with these things'. In fact, though I knew this post might arouse anti-nuclear sentiment, I'm very pro-nuclear. There is a reason three mile island would NOT have been a Chernobyl if it had totally melted the core and that is it had a containment structure. Chernobyl had no containment dome at all, the operator on duty that night broke no less than SIX critical safety rules to do his extremely dangerous stupid test. Nuclear power can be very very safe when done properly and with strict oversight. And persephone, I think you're missing the inverse relationship between half-life and radioactivity of a substance. A substance with a half life of 10^19 years is utterly harmless BECAUSE the half life is so long. In fact, I'll wager you've EATEN significantly large quantities of a radioactive substancec with exactly this length of half-life......its bismuth! As in, the pink tummy remedy, pepto-bismol! As Marie Curie said, nothing is to be feared, it is only to be understood.