“I stick my hand (momentarily) directly into liquid nitrogen but don’t suffer any injuries due to the Leidenfrost effect.

The Leidenfrost effect is the formation of a gas barrier between a hot surface and a boiling liquid if the temperature difference is great enough.”

Link

A woman plays all parts of the original Star Wars score at once with a sine Electone organ.

Link

Do you know? The contest on the always hilarious QI does – and lots more about the elements too.

Link

You’ve probably heard of the famous thought experiment – but this is a very nice explanation on how it actually works.

Link

YT:
This is a 1940′s Doran Cunningham air horn. Usually found on WWII US Navy destroyer ships, and also found on some older ferries. There are only 2 of these that are being used that I know of.

Link