> Angela Merkel (relevant: probably the only physicist head of state)

That's actually fascinating. She was a physical chemist research scientist, not just undergraduate [1]. I wonder how many other scientist heads of state there have been.

Margaret Thatcher was a research chemist (food scientist) [2], but that's the only other one I know of.

Edit: she was the first British Prime Minister with a Science degree [3].

  [1]: https://en.wikipedia.org/wiki/Angela_Merkel 
  [2]: https://en.wikipedia.org/wiki/Margaret_Thatcher
  [3]: http://www.lrb.co.uk/v35/n11/david-runciman/rat-a-tat-a-tat-a-tat-a-tat