[Ophiucus]

Has anybody combined the two elements into water using artificial heat?

Basic hydrogen combustion - "burn" hydrogen and the product is water. Consider a hydrogen powered car. Water comes out of the 'tailpipe.'

I've seen hypotheses where the high energy 'storms' of early Earth had a component of hydrogen combustion giving off water vapor. As the Earth cooled, the remaining vapor condensed into seas and oceans.

[William Terrell]

Mighty lot of free hydrogen and oxygen. Takes two hydrogen and one oxygen to make a molecule of water? Considering the amount of water on Earth, in all forms, where did the gasses come from?