# Understanding the effects of gravity on a gas

1. Aug 29, 2010

### striphe

If a gas is enclosed in an insulated container on earth, I understand that at the top of the container there will be less pressure than at the bottom due to gravity.

What I want to know is if the top is colder due to the effects of gravity. If reliable sources could provided it would be appreciated (I can't seem to find any).

2. Aug 29, 2010

### Curl

3. Aug 29, 2010

### striphe

Can you go into it any more than just simply 'no' curl, as to why?

4. Aug 29, 2010

### mikelepore

The kinetic theory of gases describes the atoms or molecules of a confined gas as having a random distribution of the x,y and z components of velocity, and they move in straight lines until they collide with the container walls and bounce off. That description leads to a mixing that would have the population of molecules in any region of the container having the same average kinetic energy as the molecules in any other region of the container.

To produce the difference in pressure between the top and bottom due to gravity, change the reference to motion in straight lines into a reference to motion in parabolas that are very nearly straight lines. This makes the density and pressure slightly less at the top. Whether that causes a slight temperature gradient, I don't remember.

5. Aug 30, 2010

### D H

Staff Emeritus
Wrong. The answer is yes. First off, Wikipedia is not a reliable source, and secondly that wiki article doesn't say anything about the question being asked.

Lots of people go to the mountains in the summer to escape the heat. Think about that for a second.