# Distribution of Stars in Milky Way and globular cluster analogy

Just a quick (and hopefully simple) question on the distribution of stars in the Milky Way and in globular clusters. I was wondering why it IS NOT possible to describe the distributions of stars in both these systems by analogy to the distribution of air molecules in a room.

Are we talking of the more random motion of air molecules as well as the relatively large number of collisions between air molecules...something which we wouldn't see in a galaxy. I'm assuming also that air molecules do not have the same central gravtational potential...and therefore do not move relative to some fixed point. That is to say, that it is much more random? Any advise on this point would be greatly appreciated.

• @ConradTurner Because the gravitational force between air molecules in a room is of order $10^{40}$ times smaller than the short range electromagnetic forces at typical separations. – Rob Jeffries Oct 6 '15 at 13:22