Search results

  1. A

    Nanorex mechanical design software

    Nanorex, Inc. is due to release its NanoEngineer-1 software this fall. With this software you will be able to design your own atomically precise mechanical machines. It may be ten to twenty years before we have the capability to actually synthesize such devices on demand, but we can simulate...
  2. A

    The JAL 1628 UFO event

    Ivan, thank-you for maintaining this forum. I watched the" that you find such validation, and explain why you interpret it as such.
  3. A

    UAV/bunker-busting frisbee [Broken] ...and while we're on the subject, I'll just mention that someone recently" Oddjob's hat for $33,600...
  4. A

    Spectacular! 3-D Chalk Drawings

    Check out these 3-D chalk drawings done by Julian Beever [Broken]
  5. A

    Hydrogen 1S-2S transition frequency

    I'm reading some papers on recent measurements of the hydrogen 1S-2S transition frequency, and they report 2466.061 THz (with about nine additional digits of precision :smile:). However, when I calculate this frequency from the "exact fine-structure formula for hydrogen" (using 1S(n=1,j=0) and...
  6. A

    Interactive timeout

    Since yesterday I have lost two posts that I was editing due to interactive timeouts. When I went to save the posts, I was prompted to login, but the posts weren't saved and when I used the back button none of the text that I had typed in was there (only the quoted material from here I have...
  7. A

    20Q: This game is cool Think of an object, and then answer 20 questions about it while the AI software tries to guess what you're thinking of. The software will guess right most of the time. You can also buy a handheld version of this game.
  8. A

    Pregnant for 46 years

    In case anyone is interested, there is a show on the Discovery Health Channel (right now) about a woman who has been pregnant for 46 years.
  9. A

    Giving Thanks

    Thank you Physics Forums staff, administrators, and helpers. Your patience and professionalism is greatly appreciated!
  10. A

    Forensic Reconstruction of Copernicus' Face

    This purports to be a forensic reconstruction of Copernicus' face. Not sure exactly where to post this, but would like to share it with the widest audience possible. [Broken]
  11. A

    Relativity without the aether: pseudoscience?

    Special relativity (SR) SR and Lorentz ether theory (LET) are empirically equivalent systems for interpreting local Lorentz symmetry. These two theories are equally valid, but it is not possible (so far) to demonstrate the truth or falseness of the postulates of either theory over the other by...
  12. A

    Einstein's Clock Synchronization Convention

    Just a friendly reminder, the first postulate of the special theory of relativity, namely that the speed of light c is the same in all inertial frames, only holds true in view of Einstein's clock synchronization convention. There is no experimental basis whatsoever for preferring this convention...
  13. A

    What's in your differential geometry toolbox?

    I saw GRTensorII mentioned here awhile back. What are the most powerful tools out there (which still run on a PC), including user manuals and texts, that you would recommend for working with field equations, curvature tensors, line elements, etc?