Recently I have been debating the merits of fillers in Thermal Interface Materials (TIMs) over unfilled TIMs. There seem to be two schools of thought on the matter:

1. An unfilled TIM displaces air in the micro pores between mating surfaces therefore increasing the contact area and therefore bettering the thermal conductivity. Adding a filler to the TIM would increase the separation between the two surfaces and actually decrease the thermal conductivity compared to the unfilled TIM. 

1. Fillers Increase the thermal conductivity because of their own conductive properties and the TIM is just a “support” to hold these particles in a suspension for good application. A TIM with a more thermally conductive filler will be a better TIM than an unfilled TIM because of the good Thermal Properties of the filler.

This problem has been of great interest to me lately as I plan to build a computer and need to choose the best TIM to ensure good heat transfer from the components to the heat sink and am stuck between unfilled or filled TIMS. Does anyone have any incite into TIMs? Can anyone help?

What material has the lowest coefficient of friction? 

someone said that a ball of glass bounces higher than the ball of rubber.is it true?doesn't the glass bal break?

which one carbon fiber/kevlar is a better non conductor, as i have read many site and they dont relly tell you the non conducting qualities of each materials, many thanks.

Not as you see it, but as a cross-section, I mean - how thick is the layer of graphite/carbon? How many atoms thick?

Some have claimed that using a dimmer to slowly turn on or off an incandescent light bulb would (in a practical sense) allow it to last forever. At last check, there's some light bulb in a Northern California fire station that is said to be burning continuously for about a century.

An expert claimed to have some quantum mechanical explanation, but I never did hear it. Can anyone explain this phenomena in English? Has anyone seen a bulb blow out when not being turned on? (I think I've seen one blow out in the middle of usage -- after about ten minutes -- but I can't swear to it.)