Teflon talk 7535

Ken Davey

You need to take a walk through the Hirschhorn museum to see the "Black Hole" that's a hemisphere with such a low albedo that you can't focus your eyes on it. In normal, bright museum light, it's the blackest thing I've ever seen. Or, rather, not seen.

With a good definition of "rough" that includes certain characteristics. A wavy mirror and a flat mirror will have virtually no difference in their energy performance. It's not until the irregularities begin to force reflection to another part of the surface that any increase in energy absorption occurs.

That's guesswork. There are certainly surface irregularities, but the necessary physical condition for your thesis to obtain is for the valleys and hills to be jagged and capable of trapping light for many bounces before exiting. Being non-specular, reflections from the dull side merely demonstrate that there are many angles of incidence-reflectance at work, but they don't necessarily imply an appreciable difference in energy absorption.

Dealing with light, the energy is trivial. Dealing with heat scales up the quanbreasties a good bit. The buttumption of "imperfections" capable of trapping heat or light is guesswork.

This is in the realm of laboratory micro-measurements, not kitchens. The energy delta between the two sides will be meaninglessly small in practical application. I'd be interested to see some hard numbers about this. My own experience with foil in restaurant use doesn't bear it out.

Here;'s a funny "Ask a scientist" site I just found:

Scientists disagreeing with each other. Wonderful.

As I'm seeing it, the conversation is about heat transfer-reflectivity in aluminum foil.

Pastorio