A science question

I think that calling IR radiation "heat" is sort of incorrect.Heat is a measure of the velocity of the molecules of a material. It is a form of energy. If that is a definition of heat then IR radiation is not heat. If heat is energy in the electromagnetic spectrum then I don't see why radio and gama radiation isn't "heat" too.We call a lamp that radiates in the IR (or mostly in the IR) a "heat" lamp because that is how we sense it. The IR radiation transfers energy to our skin which produces a sensation of heat.My conclusion would be that IR radiation is not "heat" but then I think we might be using heat in too careless and colloquial a way.

This statement is simply wrong. The reason you don't feel them as "heat" are two fold (I believe). One is that the intensity of the remote control is very very low. If it put out the several 10's of watts that a bathroom "heat" lamp put out you would feel it so some degree. Also the different wave lengths of EM radiation react differently with your skin. Some are poor at transmitting the energy they carry and so will not be experienced as much as heat (or not at all). Gamma radiation will, in a lot of lower intensites not be experienced at all as most will pass through you. Some radio waves will definitly be experienced as heat. There was a suggestion that by using the right wavelengths it would be possible to heat a home by making each room into a large microwave. As long as they didn't penetrate too deeply they could warm you without warming the air and so be very efficient. I think they would have a major PR problem though (however good the science behind it) .So a wide range of different wavelengths will allow an energy transfer. That will raise the kenetic energy of the skin and be experienced as heat. Some wavelengths will be inefficient some not.There is no "heat" energy. Heat is a manifestation of the kenetic energy of the atoms of materials. It is colloquially called "heat energy" for that reason.

As a pretty good rule of thumb: always go with Sylas's posts. If they are different from mine 99/100 it is mine that is wrong.This message has been edited by NosyNed, 03-07-2005 02:35 AM

I think you may have most of it now. But I'm not going to comment without more reading and thought.Heck, I thought I knew something about this (I do have a degree in physics -- but it is past it's best before date). It is clear that there were things I didn't understand right.That is something I like about here. A chance to learn.This message has been edited by NosyNed, 03-07-2005 20:21 AM