Question: Why can't you breath in space

Tim Knapp answered on 1 Oct 2020:

OK good question, difficult to answer simply.
Ill try.

We need air to breath
There is next to no air in space.

Getting a bit more complicated. Air is made of molecules of gases, most is nitrogen 79% (it doesn’t do anything its just there) and around 21% oxygen (we need that to live).

Everything is affected by gravity even gas molecules. Oxygen and Nitrogen are pulled towards the surface of earth. At sea level the amount of gas around you presses down (because there is molecule upon molecule stacked on top of each other). Those gas molecules weigh around 10kg every square metre area.

So near sea level there’s lots of gas molecules, plenty of oxygen.

If you were to go up Everest which far above sea level there is now a lot fewer molecules of gas above you. the air pressure or weight has dropped to about 3.4Kg every square metre so that’s about a third of the amount of oxygen there is at sea level, but that is still on earth about 8.8 Kilometres (Km) above sea level. Now take a rocket and travel into space 40 or 50 Km and there is next to no molecules of gas, no oxygen, no nitrogen.

That’s the long answer 🙂