Recent content by gmalcolm77

Haven't figured that out yet. Just a dumb old guy interested in science. Please forgive.

Yea, I figured so, otherwise it's energy would eventually be infinite. The MIT quote I believe is a bit misleading. Thanks.

Summary: MIT researchers have created a material that is 10x blacker than any other material ever recorded. The foil captures at least 99.995% of incoming light. Does this mean that there is practically no EM re-radiated?

OK. Great answers, thanks.

How can a black hole evaporate due to Hawking radiation? Aren't they constantly attracting real matter anyway? o_O

Sorry, typo corrected.

OK, so let's get rid of the spaceship since we don't need it anyway. A photon traveling at c undergoes spontaneous parametric down-conversion when it runs into a crystal(not moving) and splits into two new photons. Would the two new photons be seen?

Well, try to think of it this way: It is impossible for me to run a hundred miles an hour, but if I could, would I get to that town 100 miles away in one hour? :cry:

Yes, it is a what if question, but wouldn't an outside observer see a light? ?:)

That's interesting, as Feynman said in QED that "...every phenomenon about light that has been observed in detail can be explained by the theory of quantum electrodynamics." And later he explained that the reverse was not true. That wave theory could not explain some phenomenon that QED...

I find it difficult to conceptualize red shift when thinking of light as a stream of photons. In thinking of it as a wave phenomena, I can see it as a matter of a given energy concentration/area. But why should a photon lose energy as a result of the velocity of the emitter?

What would be seen if the ship is traveling at the speed of light? Just a single flash at the center of the ship?

http://www.nptel.ac.in/courses/122106034/ by Prof. V. Balakrishnan http://www.nptel.ac.in/courses/115104096/ by Prof. Manoj Harbola Thanks for the timely information and I will definitely do one or both of these courses. Malcolm. :biggrin:

:rolleyes: I would like to find a free online course, not too hard. I have minors in math and physics, but have been away for awhile. Maybe something on youtube. If someone knows of a decent course that I could educate myself with I would appreciate any info on it. Thanks in advance...

I thought that the emission control would turn the engine off before there was more than a safe level in the garage. Was it just an urban legend that it is now difficult to kill yourself with a tube from the exhaust pipe? Perhaps I am just gullible. No, I don't think it is that the engine turns...