On Mon, May 27, 2013 at 5:22 PM, Harry Veeder <hveeder...@gmail.com> wrote:
> > > On Mon, May 27, 2013 at 5:44 PM, Joshua Cude <joshua.c...@gmail.com>wrote: > >> >> But we have no idea what the emissivity of the paint used in the December >> test was, nor whether it was wavelength dependent. There may be a paint >> for which an assumption of emissivity of 1 greatly overestimates the power. >> A few measurements could have excluded this possibility. >> >> > > > This book > > _Absorption and Scattering of Light by Small Particles_ > > says for a body to have an emissivity > 1 it can't be much bigger than the > wavelength it radiates. > I'm not suggesting emissivity greater than 1. I'm suggesting we don't know how the correction for a limited wavelength range goes for low emissivity (this could be answered with a bit of effort, or by an expert in the area), and more importantly, we don't know if the surface has a wavelength dependent emissivity, in which case, an assumption of unity could err on either side of the true value of the power depending on the particular dependence.
