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# Science questions answered for laymen

#### It's Snake Pliskin

This thread can be for science questions we laymen might have regarding science.

First question:

In the vacuum of space that would be encountered in an Earth orbit would:

a. a water bubble or oxygen bubble (gas bubble) move in an undirected way without evident force?
b. a water bubble or oxygen bubble (gas bubble) move in a direction evident as though it had force propelling it?

This scenario could be applied to, say a space walk or inside a vehicle capable of carrying man. Even these guys:alien2:

#### jonojpsg

This thread can be for science questions we laymen might have regarding science.

First question:

In the vacuum of space that would be encountered in an Earth orbit would:

a. a water bubble or oxygen bubble (gas bubble) move in an undirected way without evident force?
b. a water bubble or oxygen bubble (gas bubble) move in a direction evident as though it had force propelling it?

This scenario could be applied to, say a space walk or inside a vehicle capable of carrying man. Even these guys:alien2:
I like it - a science nerds thread

I would have thought that the Brownian motion of the water molecules inside the droplet may impart some motion on the droplet, BUT the net force of the molecules hitting the inside surface may in fact be zero.

A great video of water in zero g -

PS How do I embed a video in a post?

#### skyQuake

This thread can be for science questions we laymen might have regarding science.

First question:

In the vacuum of space that would be encountered in an Earth orbit would:

a. a water bubble or oxygen bubble (gas bubble) move in an undirected way without evident force?
b. a water bubble or oxygen bubble (gas bubble) move in a direction evident as though it had force propelling it?

This scenario could be applied to, say a space walk or inside a vehicle capable of carrying man. Even these guys:alien2:
Ok I'll bite:

First of all there would be no such bubble, the vacuum of space would make it explode.
Excluding centrifugal force, I don't think theres any force propelling it in any specific direction. (assuming it doesnt fall out of orbit)

#### It's Snake Pliskin

Ok I'll bite:

First of all there would be no such bubble, the vacuum of space would make it explode.
Excluding centrifugal force, I don't think theres any force propelling it in any specific direction. (assuming it doesnt fall out of orbit)
Thanks skyquake. So a gas bubble would burst or a water bubble would burst or both? Wouldn't the water bubble just float like in the video posted aboove by jonojsp? Thanks jono.

#### It's Snake Pliskin

That comes under Newtons first law of motion,

1. A body at rest remains at rest and a body in linear motion remains in motion with constant velocity until and unless an external force is applied on it.

http://en.wikipedia.org/wiki/Newton's_laws_of_motion
Thanks Naked shorts. So on Earth an oxygen bubble in water that rises rather quickly is propelled by what force?

#### spooly74

This thread can be for science questions we laymen might have regarding science.

First question:

In the vacuum of space that would be encountered in an Earth orbit would:

a. a water bubble or oxygen bubble (gas bubble) move in an undirected way without evident force?
b. a water bubble or oxygen bubble (gas bubble) move in a direction evident as though it had force propelling it?
If it's in Earth orbit it would have a force acting on it, Gravity. How long it stays in orbit depends on its speed.

So on Earth an oxygen bubble in water that rises rather quickly is propelled by what force?
Air is lighter than water.

#### Buddy

Thanks Naked shorts. So on Earth an oxygen bubble in water that rises rather quickly is propelled by what force?
If I understand your question correctly........ the answer is buoyancy as explained by Archimedes Principle, which is in summary caused by the differential pressure forces (due to the water) at the top and bottom of the bubble.

#### It's Snake Pliskin

If it's in Earth orbit it would have a force acting on it, Gravity. How long it stays in orbit depends on its speed.

Air is lighter than water.
Thanks Spooly. Is there gravity in the vacuum of space?

For example:

An air bubble comes from the helmet of a cosmonaught as he is doing a space walk. Would that bubble explode? or move because of the gravity force of the Earth due to being in orbit?

And more importantly what would become of that cosmonaught?

If I understand your question correctly........ the answer is buoyancy as explained by Archimedes Principle, which is in summary caused by the differential pressure forces (due to the water) at the top and bottom of the bubble.
Thanks Buddy.

#### Naked shorts

Thanks Naked shorts. So on Earth an oxygen bubble in water that rises rather quickly is propelled by what force?
Gravity.

#### Naked shorts

Thanks skyquake. So a gas bubble would burst or a water bubble would burst or both? Wouldn't the water bubble just float like in the video posted aboove by jonojsp? Thanks jono.
The bubble of liquid water would turn into a gas if exposed to the vacuum of space. This is because there is no pressure forcing the molecules together.

#### It's Snake Pliskin

The bubble of liquid water would turn into a gas if exposed to the vacuum of space. This is because there is no pressure forcing the molecules together.

#### Buddy

Thanks Spooly. Is there gravity in the vacuum of space?
Aah, gravity. It's everywhere, it's everywhere!

An air bubble comes from the helmet of a cosmonaught as he is doing a space walk. Would that bubble explode? or move because of the gravity force of the Earth due to being in orbit?
It wouldn't really "explode", more like disperse into the vacuum of space. The "air" is subject to exactly the same gravitational forces as the guy with the helmet.

And more importantly what would become of that cosmonaught?
Gotta watch those peskie Russian cosmonauts. If the "air bubble" is under significant pressure, the Ruskie might find himself going backwards at a significant rate of travel. Newton's laws and all that.

#### happytown

Is there gravity in the vacuum of space?
galaxies 'collide' and merge courtesy of gravity, eg NGC 5257 & NGC 5258 (currently in the early stages of a cosmic meet 'n greet)

cheers

#### Gillie

The bubble of liquid water would turn into a gas if exposed to the vacuum of space. This is because there is no pressure forcing the molecules together.
Would've thought that the bubble of liquid water would freeze before it had time to turn into gas and escape into the vacuum of space, as long as there were no sunlight, hence there is a force holding the molecular chains together. The real temperature in space is about 3 °K (-270 °C or three degrees Celsius above Absolute Zero). Absolute zero is the temperature in outer space without any sunlight. In sunlight the temperature can rise to 120 °C/ 250 °F (So typically the liquid water bubble would be turned gaseous). There are still molecules in space just very few of them.

#### skyQuake

Would've thought that the bubble of liquid water would freeze before it had time to turn into gas and escape into the vacuum of space, as long as there were no sunlight. The real temperature in space is about 3 °K (-270 °C or three degrees Celsius above Absolute Zero). Absolute zero is the temperature in outer space without any sunlight. In sunlight the temperature can rise to 120 °C/ 250 °F (So typically the liquid water bubble would be turned gaseous). There are still molecules in space just very few of them.
A ball of ice exploding?

Depends how the ball of water got up there in the first place.
Hollywood has imprinted too much floating globs of water in space stereotype

#### Gillie

A ball of ice exploding?

Depends how the ball of water got up there in the first place.
Hollywood has imprinted too much floating globs of water in space stereotype
Well, if you think of it, comets are exploding balls of dirt and ice. The coma and tail of the comet is the ice evaporating into space when heated by the sun on it's approach.

#### jono1887

How about a new question... if you were to travel at the speed of light, is it possible to travel back in time?

#### Gillie

How about a new question... if you were to travel at the speed of light, is it possible to travel back in time?
Not according to relativity.

#### skyQuake

Well, if you think of it, comets are exploding balls of dirt and ice. The coma and tail of the comet is the ice evaporating into space when heated by the sun on it's approach.
Yup, that water was already attracted to the comet by gravity and was already frozen.

However if you magically get a 'ball' of water into space, would it freeze first or dissipate or explode?