How much water would it take to put out the Sun? Your first guess is probably – a shit ton. Like, a LOT of water. Billions of gallons, maybe double that or double that again. That would at least dampen it, right?
Those of us that aren’t overly knowledgeable in chemistry may be surprised to find out that although the Sun may look like it’s on fire, it isn’t the same as the fire you and friends sit around down the beach in the summer, or the type of fire that cuts a swathe across the Australian outback, or cooks your marshmallows when you’re out camping.
In fact, it’s not on fire at all.
The Sun's heat and light is actually a by-product of nuclear fusion, rather than one of combustion. Adding water would actually make the sun's reactions increase in rate – by providing more hydrogen as fuel for nuclear fusion – causing it to burn even brighter. Which is definitely not what the goal was.
Check out the video by Universe Today explaining a way that, if so inclined, you may be able to destroy the Sun after all:
