Can you collimate a diffuse source of light?

[NeoPTLD]

I really don't see why you can't by using combinations of different mirrors and lenses, but something that I found on the newsgroups says:

"In thermodynamics there is
entropy that cannot be violated and in optics diffuse light cannot
be collimated. "

Ok, so lets say reflectors and lenses are 100% efficient. Is it possible to collimiate a four foot, 3,000 lumen fluorsecent lamp source into a focused beam like a 3,000 search light if there's no limitation on the size of the optics?

 

[iamaelephant]

This would not violate thermodynamics. The entropy would still have a net increase through various other sources, such as the heat generated in the glass among other things. I can't think of any reason why diffuse lighting could not be collimated, but maybe someone here might have a better understanding. The way I see it, this would not violate thermodynamics any more than a focussing lense would.