Everyone always says that there has always been, and always will be, the same amount of water on planet Earth.
What about space travel?
They obviously need water in space, so they must take it up with them. Take the International Space Station: astronauts must survive up there for around 6 months. And yes, I know they have ways to recycle it, but it must eventually be "refreshed".
I know that it makes the only teeniest, smallest of differences (a few hundred gallons taken from billions of gallons), but could that phrase be proved wrong?
Thanks in advance!
Note: I put this on the Earth Science SE because I couldn't find anywhere else it would fit.