Naked Science Forum

Non Life Sciences => Physics, Astronomy & Cosmology => Topic started by: paul.fr on 06/12/2008 23:33:08

Title: How does the water in a water balloon behave in zero gravity?
Post by: paul.fr on 06/12/2008 23:33:08
Two questions about how the water in a water balloon would act in zero gravity.

What would happen if an astronaut held out a water balloon and then popped it with a pin?

What would happen if the same astronaut threw a second water balloon at his colleague?
Title: Re: How does the water in a water balloon behave in zero gravity?
Post by: Don_1 on 06/12/2008 23:41:33
If you watch an ultra slowmotion film of a water filled balloon being popped in normal Earth gravity, you will see the water retains it's shape for a spilt second. In zero gravity I should think apart from the disturbance caused by the balloon rubber returning to it's unstressed size, the water should retain it's shape.
Title: Re: How does the water in a water balloon behave in zero gravity?
Post by: Bikerman on 07/12/2008 00:40:59
In zero g then the water will act to form a sphere (minimum surface area per volume). The balloon will simply reinforce this behaviour....
Title: Re: How does the water in a water balloon behave in zero gravity?
Post by: lyner on 07/12/2008 12:44:13
One large sphere would be very unstable* but, in a big enough container (removing local gravity effects) with perfectly still air surrounding it, it would stay spherical.
In orbit (microgravity) the shape would be slightly ellipsoidal (prolate / 'egg' shape) with the long axis pointing  towards the centre of Earth.

*There are many Utube Movies which show this sort of thing. C4 yourself.