Spirit levels... in space

[handpaper]

A spirit level requires that it be subject to a force which is resisted by the surface on which it is put - gravity is just the most common example. In the absence of gravity, a spirit level can be used to define a plane normal (perpendicular) to any acceleration; it can tell (indirectly) you in which direction a rocket is accelerating.
If an accelerative force is not resisted, the spirit level will not work.
This would be the case in the absence of any gravitational force (rare) or in the absence of resistance. If the spirit level is falling freely (ie in orbit) it will not give any reading.

[Cactussed]

Dibble said:

Would a spirit level (bubble in fluid type, not some electronic thing) "work" in space (ie almost zero gravity), or do they require gravity to work?

I think the bigger question is, if it were on a treadmill, would if take off?

[Dibble]

handpaper said:

A spirit level requires that it be subject to a force which is resisted by the surface on which it is put - gravity is just the most common example. In the absence of gravity, a spirit level can be used to define a plane normal (perpendicular) to any acceleration; it can tell (indirectly) you in which direction a rocket is accelerating.
If an accelerative force is not resisted, the spirit level will not work.
This would be the case in the absence of any gravitational force (rare) or in the absence of resistance. If the spirit level is falling freely (ie in orbit) it will not give any reading.

So is that a "yes" or a "no", then?

[GreenV8S]

In free fall it wouldn't work. If the engines were on it would show 'up' in the direction of acceleration.

[Dr Jekyll]

Eric Mc said:

groucho said:

Last time I levelled up my shelves on Jupiter they seemed to work.

What did you stand the shelves on?

It is gravity that makes the bubble shift - so on a Zero-G environment the bubble wouldn't move properly.
What would you want a spirit level in space for anyway? I wouldn't see a set of open book-shelves being useful on the Space Station.

There is more gravity on Jupiter than down here so that's cheating in any case.

[Strangely Brown]

grumbledoak said:

In almost zero gravity they would almost work.


Well away from the planet, not at all. Though I'm not sure what the bubble would do; probably float about seemingly randomly, depending more on how you move the 'container'.

The air would become a single bubble in the middle with the water on the outside and it would break into hundreds of tiny bubbles if shaken, then slowly reform. It was one of the experiments carried out by Pavel Popovich on Vostok 4.

Edited to correct.

Edited by Strangely Brown on Sunday 29th March 20:37