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        riddles >> easy >> In space, what happens
        
(Message started by: Noke Lieu on Sep 15^th, 2005, 12:17am)

Title: In space, what happens
Post by Noke Lieu on Sep 15^th, 2005, 12:17am

If you open a bottle of carbonated/fizzy water in a "zero G" environment?

What happens to the bubbles?

(Another question that popped into my head whilst washing up)

Title: Re: In space, what happens
Post by Neelesh on Sep 15^th, 2005, 12:46am

In a carbonated water bottle the gas is filled usually under pressure. If the pressure is reduced, the gas will certainly expand. This has nothing to do with gravity....

An interesting point to note would be to invert the bottle and then open it. In Zero G environment the gas will come out, liquid will remain in the bottle.
?
Not sure . Its all just a guess.

Title: Re: In space, what happens
Post by towr on Sep 15^th, 2005, 3:05am

I suppose the bubbles will simply expand, but lacking any up or down, won't move in any particular direction.
So I wouldn't expect foam to form on top, but rather everything to turn foamy.

Title: Re: In space, what happens
Post by Noke Lieu on Sep 15^th, 2005, 4:47pm

Those together are pretty much my take on it, except that I'm not so sure about the upside down thing- there is no upside down. The liquid/gas mixture volume increases, it is forced out of the bottle.

Title: Re: In space, what happens
Post by WarZone on Sep 16^th, 2005, 11:57am

I believe that with the air rushing out of the bottle, it would force a bit of soda out with it ;)

Also, I don't believe in pure null-g. No matter what, there is always some faraway planet[oid] creating that .00000000000000000000000000001% gravity. In conclusion, some soda is bound to come out over time and travel toward that mass.

Correct me if I'm wrong ::)

Title: Re: In space, what happens
Post by towr on Sep 16^th, 2005, 1:54pm

on 09/16/05 at 11:57:16, WarZone wrote:

Also, I don't believe in pure null-g. No matter what, there is always some faraway planet[oid] creating that .00000000000000000000000000001% gravity. In conclusion, some soda is bound to come out over time and travel toward that mass.

Correct me if I'm wrong ::)

It's not a matter of whether there is gravity. Every satelite and spaceship in orbit around earth experiences the force of gravity. But since they' (and everything in them) are free-falling, everything experiences the same acceleration, and thus 0 with respect to each other.

Title: Re: In space, what happens
Post by Icarus on Sep 16^th, 2005, 2:46pm

In freefall environments in the presence of gravitational forces, only the center of gravity of the satellite/spaceship/etc. is truly at zero g. Everywhere else, there is a small imbalance between the inward gravitational force and the outward "centrifugal force". This imbalance is called "tidal force", or just "tide", because in the Earth/Moon system, it is responsible for ocean tides.

The effect of this tidal force is to push things outward from the CG of the ship. The effect works in all directions, so anything in the ship that is not directly in the middle will be pulled - very lightly - towards the nearest wall (assuming the CG to be in the center of the open area).

However, you could grow old waiting to see this effect in something as small as the space station, so its effects on the carbonated water are negligible.

Title: Re: In space, what happens
Post by Grimbal on Sep 17^th, 2005, 3:34pm

This effect shows when the station is rotating. And how strong it is depends how fast it rotates. And it wouldn't affect a free floating object in the middle of an open area that is not rotating itself.

The tidal force is a little more complicated. It appears when a station (or the moon) is in orbit around earth or any heavy body. It comes from the fact that gravity from Earth doesn't exactly cancel the centrifugal forces. Both forces cancel at the station's CG.
- If you move away from earth's CG, the gravitational force decreases and the centrifugal force increases. The net force is away from the earth's CG.
- if you move closer to earth's CG, the gravitational force increases and the centrifugal force decreases. The net force is towards the earth.
- if you move at a right angle from the earth-station axis, the gravity will pull you back towards the axis. If the station is rotating with its movement around earth, that effect is compensated in the direction of movement but not the perpendicular direction (parallel to the axis of the station orbit).

The result is that a body will tend to elongate in the direction of the body-earth axis and compress in other directions.
See http://en.wikipedia.org/wiki/Spaghettification