During WWII, a U.S. naval destroyer won a battle against a Japanese submarine by throwing potatoes at them. The Japanese thought they were grenades.
Scientists discovered sharks that are living in an active underwater volcano. Divers cannot investigate because they would get burns from the acidity and heat.
In 2009, Stephen Hawking held a reception for time travelers, but didn’t publicize it until after. This way, only those who could time travel would be able to attend. Nobody else attended.