General oc/temp questions

When people talk about overclocking it's almost always about lowering the temperature of the cpu. Is that because a cpu runs more stable at lower temperatures, or is it so that you can aford the increasing temperature as you clock the cpu to higher frequences?

Are there any theoretical limits as to how much you can cool your cpu untill it doesn't work because of too low temperatures. Like using a liquid nitrogen cooler instead of a normal cooler. I could imagine some problems like the silisium getting very brittle and it being a semicunductor internal resistance would also start to increase as the temp is lowered.

And finaly does the old trick of submerging the motherboard into an oil bath where you put some big heat sinks onto the components and some propelers to keep the oil moving more that it would by normal convection still work.

There is a point at which more cooling doesn't provide room for higher overclocking. It also becomes far less practical, as you are using a lot more power for overclocking and even more for cooling the processor. You must also have a really good insulator, or else the motherboard will become cool and water vapor from the air will condensate on your board, shorting everything out.

<font color=blue> Blowing things up smells aweful... </font color=blue>