I Gas molecular attraction in the sense of Newton's law

[Bernadette]

TL;DR

Attraction between gas

Hello

What experiment or observation shows that for atoms, molecules or masses of gas, there is attraction in the sense of Newton's law (universal attraction)?

Bernadette

 

[jedishrfu]

Astronomical observations would indicate that the gases in nebulas stay together by gravity. Similarly for the sun composed largely of hydrogen atoms.

 

[Drakkith]

The atmosphere exhibits all the predicted phenomena of gas under the influence of gravity. Density gradient, buoyancy of less dense gases and pockets of warmer air, the escape of hydrogen and helium from the atmosphere but not heavier gases, and more.

For evidence that gases generate gravity themselves and react to this gravity, astronomical phenomena are perfect examples, as jedishrfu pointed out.

 

[vanhees71]

Another example is the theory of stars, which are held together by gravity and hindered to collapse by pressure. For usual stars like our Sun Newtonian theory is sufficient. For, e.g., neutron stars you need general relativity (Tolman-Oppenheimer-Volkoff equation).

 

[Herman Trivilino]

The gravitational force between two molecules is too small to measure using existing technology.