Recent content by bdrosd

I believe the original post asks about the emissivity of space, which is probably about 1.0, and a ballpark figure for the temperature of space is about 0 (2.4 kelvin to be a little more precise). You will also need to know the emissivity of the shuttle itself, along with the surface area...

I wonder if lin howt is concerned about the air pressure acting on the sides and top of the book but apparently not on the bottom surface? Of course this is not the case, air can almost always get inbetween the book's bottom surface and the table and thus push upwards with almost exactly the...

I'm hoping some one out there has as conceptual explanation as to the origin of Ferromagnetism. I know the magnetic fields are produced by moving charges and that atoms have moving electrons and hence display paramagnetism. Just a few pure elements have the ability to produce a permanent...

Years ago I was using an electron microscope (transmission type) when I realized that the current of the electron beam was such that electrons were traveling through the sample one at a time. This makes it difficult to explain electron diffraction (which I was observing quite well) since there...

Wet cardboard, that's a good idea. Could you describe the "pattern", were there stripes, or was it linear array of spots? When I did it I was looking for the 6-7 cm spacing and I found it, but I doubt it would have convinced a skeptic

lpfr, I just realized that we traded a few responses a few weeks ago regarding reflections of light from smooth metal surfaces. I was attempting a quantum explanation in terms of photons; you had a classical E/M explanation. It seems to me that both approaches have to work, but if the light...

I'll be waiting for results with bated breath

Well then, your microwave oven would be ideal to check out how well you can detect the antinodes. The spacing should be ~6.5 cm (frequency=2.45 GHz). I cut out a piece of cardboard to fit the inside cavity and then completely covered it with thin slices of American cheese. As I said, I got...

lpfr, I'm not an expert but I believe that they do all have the defecting fan in addition to the rotating table.

Incandescent bulbs are more likely to burn out just as they are turned on, so there is some truth to the recommendation not to flick them on and off more then necessary. However, if you leave the light on long enough, you are guaranteed to burn it out, so you can't go too far in that direction...

Has anyone out there actually tried the kitchen experiment of placing a continuous line of meltable food (i.e. marshmellows/chocholate/cheese etc.) across the bottom of a microwave oven in hopes of finding the antinodes of a standing wave by looking for regions that melt while the rest of the...

Yes, that is what I am suggesting. I have no idea how long that would take. However, it seems to me there is no other way to explain the previous presence of surface water (and therefore an atmoshpere) and the current absence of both. How Mars's magnetic field could have just "quit" is not at...

I didn't say "hold" but rather "preserve". What I ment by that was that the magnetic field protects the atmoshphere from errosion by the particles in the "solar wind" which can impart sufficient kinetic energy to the molecules that they can exceed the escape velocity.

I hope someone can clear up some issues about Mars's atmosphere, specifically: -- Since most evidence indicates that Mars once had surface water, I assume that it must have had a considerably more substantial atmoshpere than it currently has. --- A magnetic field is necessary for the...

"white light" is an expression for light of all visible wavelengths. Light of a single wavelength will have a specific color (to our eye). Light of a single color produces interference patterns. In fact that is usually what you see in textbooks; a pattern of interference fringes due to a laser...