Almost pfilosophic question

[Yegor]

How we can proove, that molecules and atoms really exist?
As I know in the beginning of 20th century Boltzman commited suicide, because couldn't proove existence of molecules. How we can proove this statement for a kid, for example. Can we solve this problem without Mathematics and diffisult experiments?

[dextercioby]

Ludwig Boltzmann (sic) is said to have commited suicide because nobody accepted his theory of (non)equilibrium statistical mechanics,especially the H (or "ita") theorem,the equation and the consequences.As Josiah Willard Gibbs proved it,everything Boltzmann did was perfectly correct (except the suicide part :tongue2:),even though Henri Poincaré's theorem would invalidate it,even at classical level...

Boltzmann is the first god of theoretical physics.

Daniel.

[Yegor]

Does anybody believe that molecules exist? Are You sure? Why?

[HallsofIvy]

Actually, Albert Einstein was given the Nobel prize for his paper on Brownian Motion (NOT specifically for his papers on relativity that were published the same year) largely becase it gave the first convincing proof that molecules exist.

I might point out that molecules have now been actually photographed, using electron microscopes- that's pretty convincing proof! (Unless, of course, you don't accept that electron microscopes exist!)

[Yegor]

Of course I accept existance of molecules, electron microscopes etc.
Just my Physics lecturer frequently asks us how we can proof this existance. He just want to make us think. I was really surprised that just 100 years ago it wasn't so obviously. We also meant Brownian Motion, and it was single thing he accepted as a proof. May be there is any other simple proof?! May be chemical reactions? Is it realy not very simple question?

[Tom Mattson]

When I encountered internet message boards for the first time, I encountered crackpots for the first time. The first crackpot I met did not believe in the existence of anything below the structure of the atom. Since then, I became interested in accumulating evidentiary statements of the existence of nuclei, electrons, etc..., besides the tracks left in particle accelerators.

Anyway, here's one of the things I turned up:

http://www.newton.dep.anl.gov/newton/askasci/1993/chem/CHEM043.HTM