Originally posted by Airscrew
Really? so all the cold air that comes in around my front door because I need to replace the weatherstriping is just my imagination....?
Well... yes... because the cold air is not coming in. The warm air is going out. Why? Because air molecules bounce off one another. The more that are bouncing, and the faster they hit one another, the more energy they transfer on impact, creating the sensation of heat.
When a colder air mass (less molecular movement) is close to a warmer air mass (more molecular movement), the molecules move toward the colder air mass, esentially the same as osmosis. They are transferring energy to the most willing receptors in an attempt to equalize energy states. This, in turn, reduces and slows the number of air molecules bouncing off one another in a local area near the conflicting air masses (near your door) making it "feel" cold.
At some point, this effect equalizes, so you only feel the "cold" around the leaky door, but not somewhere further from it.
I think I got all that right. It's been a long time since my engineering physics classes in college though.
Next we'll discuss the actual energy transfer proccess as electrons "jump" orbits around a molecular nucleus (quantum mechanics).