n4m4w45 asked: So in Level 8-4 of Super Mario Bros., there is fire under water. Is that scientifically possible, or is that just Mario bein’ Mario.

edwardspoonhands answered:

Fire is a chemical process called oxidation, and as you might guess, oxidation requires oxygen. The only way to have fire under water is to have a source of oxygen (probably a solidified source) that releases oxygen when heated up, thus allowing something (usually a fuse) to burn. 

This is also true in outer space where there is no oxygen (no gas at all) so rockets work by providing oxygen along with the fuel.

I imagine the creators of Super Mario were not thinking about this when they allowed Mario and Luigi to shoot fire balls underwater.