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.
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