Litvinenko poisoning: polonium explained

It's not necessarily a happy thing that we often use interesting deaths as scientific opportunities to learn about the human body, but it's true.

Alexander Litvinenko's death due to polonium-210 taught scientists about death due to alpha radiation poisoning. Luckily, Litvinenko, a former agent for the Russian and Soviet spy agencies, was dosed - twice, it seems - with polonium-210. After the second dosing, Litvinenko died three weeks to the day after his ingestion of the polonium-210 on November 1, 2006.

The science of how we found out it was polonium-210 and of what happened to Litvinenko are fascination.