Would helium balloons float upwards on a spaceship?

In the absence of gravity, there is no 'up' on a spaceship - so where would a helium balloon go?

Asked by: Ant Jenvey, Reading

There is no ‘up’ on a spaceship, because there is no external gravitational field to tell us which is ‘down’. In the absence of gravity there is no force to push or pull the balloons.

Helium balloons only float up in the Earth’s atmosphere because the volume of air that they displace is heavier, and is pulled downwards more strongly, effectively pushing the balloon up and out of the way.

Read more:

How many helium balloons would it take to make me float? © Getty Images

Subscribe to BBC Focus magazine for fascinating new Q&As every month and follow @sciencefocusQA on Twitter for your daily dose of fun science facts.