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Everything posted by swansont

  1. IIRC Compton scattering is consistent with particle behavior.
  2. I think the derivation is geometrical - you know the ray going through a focus is parallel on the other side, and the ray going through the center doesn't bend. You end up with a whole bunch of triangles you can compare. Properly applied geometry gives you the formula.
  3. [massive nitpick]Atomic Weight goes in a superscript or inline. Atomic Number goes in a subscript[/nitpick] U235 or U-235
  4. This summary says it was a five-point scale: 'People logging onto the LaughLab Web site were invited to rate jokes using a "Giggleometer" which had a five-point scale ranging from "not very funny" to "very funny".' I also think it's interesting that they claim: "Bizarrely, computer analysis of the data also showed that jokes containing 103 words were thought to be especially funny. The winning "hunters" joke was 102 words long. (An abbreviated version was told in this story.) Many jokes submitted contained references to animals. Jokes mentioning ducks were considered particularly funny." So wouldn't it stand to reason that if they added the word "duck" (i.e. 'two duck hunters are out in the woods...') that the joke would be much, much funnier?
  5. Whoops! Missed that one. I'm young again...
  6. swansont


    Right. You need to divide the mass by the atomic (or molecular) weight' date=' which gets you the number of moles. And there are 6.02 x 10[sup']23[/sup] per mole (Avogadro's number)
  7. Actually, the "make sure he's dead joke" was tested. "Funniest joke ever" isn't the interpretation I'd give - it was a joke that was most widely recognized as being funny, not the joke that got the biggest guffaw.
  8. 42/M/US I guess that makes me the old man 'round these parts.
  9. OK Tess. Pick these apart. I gave you the first two. There's only about 1900 more to go.
  10. To expand on this: a pinhole forces the light to have a one-to-one mapping of object and image - each point on the object has only one ray that goes through the pinhole and forms the image. So there is no way for multiple rays to focus at different depths or places and cause blurring. It's why you can make a pinhole camera. You just lose a lot of light in doing things this way. This is also why smaller apertures have larger depth-of field.
  11. Here is a link to a CalTech group doing cavity QED. Note the 0.9999984 reflectivity of their mirrors. Photons will bounce more than 2 or 3 times. Here is a Stanford group. Note the link to the "Quantum Dot Turnstile" and one of the refernces: "An efficient source of single photons: a single quantum dot in a micropost microcavity" Hint: "single" isn't referring to its marital status
  12. Given your other responses I have to assume this is sarcasm. Also unable to use Google very well.
  13. A very wealthy man is on his death bed. He calls for his doctor, priest, and lawyer. When the three of them arrive, he says to them: "I know they say you can't take it with you, but I want to try. There are three bags over there. Each has $100,000 in it. I want each of you to take a bag, and at my funeral, throw the bag in my coffin just before they close it." The next day, the man dies. At the funeral, just before the coffin is closed, the three men each drop their bag in the coffin. After the funeral, the three are talking. The priest says, "I feel so terrible, I have to confess: We are building a new church, and the building fund was $10,000 short, so I took that much out of my bag before placing it in the coffin." The doctor says, "I feel bad, too. My hospital is building a new wing, and we are also short on funds. I took $15,000 from my bag to help complete the new wing." The lawyer smugly says, "I can't believe you two! I enclosed a check for the full amount!"
  14. I'll second the mention of astronomy. Lots of amateur input. The universe is a big place, and there always seems to be room for more astronomers, as it were. You could get started soon - there's a transit of Venus on June 8. Hasn't happened since 1882!
  15. Or possibly a slight mangling of the rotating mirror method of calculating c.
  16. Yes, I believe UFOs exist. I don't believe that they are alien visitors.
  17. You might want to read The Man Who Tasted Shapes by Richard E. Cytowic
  18. An ideal solenoid has no field outside of it, so that part of it was incorrect, and thus anything derived from that notion is incorrect. Of course, a real (i.e. non-infinite) solenoid will have a field outside, since the divergence of B is zero - but the field is much stronger inside.
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