On Sun, Oct 12, 2014 at 11:43 PM, David Roberson <dlrober...@aol.com> wrote:
> I refer to the opposite effect in this case Harry. In other words, can > the color appear to be too dark in the visual region to our eyes compared > to the emission of thermal energy in the IR. > > Are there surfaces that are very poor emitters of energy in the visual > region that behave more like a black body in the infrared region? This is > more of a question instead of a statement since it seems like that might be > happening in this special case. The light emitted does not have a color > that matches what is expected to be seen from a surface of a broad band > black body. I wonder if anyone on the list has seen materials with that > characteristic. > > If you consider the behavior of a RF radio transmitter, you will > understand the jest of my question. In that case, the amount of power at > its transmission frequency, being narrow band and so low in Hertz, would > indicate a black body that was at an enormous temperature if the complete > spectrum were available as expected. But we know that it does not > represent a true black body since it is narrow band. Can anything of a > similar nature exist at other frequency ranges such as IR? > > The blackbody would still have a low temperature if the distribution peeked at radio wave lengths which are much longer than light waves. See how the temperature peek of a blackbody declines as wavelength increases: http://voyager.egglescliffe.org.uk/physics/astronomy/blackbody/Image21b.gif You are struggling to find an explanation which is consistent with the claim of excess energy and with the 2nd law of thermodynamics (heat flows from a hotter region to a cooler region). Can it be done? You can disregard what I am about to say since I am not expert in these matters but I think a choice has to be made. Either there is no excess energy or the 2nd law has broken down in this system. Harry
