Jump to content

mathematic

Senior Members
  • Posts

    1106
  • Joined

  • Last visited

Everything posted by mathematic

  1. mathematic

    Time !

    The physics of short time or short distance (Planck time or Planck distance) is very uncertain.
  2. "According to Einstein, the sum total of all of my motion equals the speed of light." Where did you get that idea?????
  3. The origin of the normal distribution is the Central Limit Theorem. The differential equation happens to be an obvious derivation of the normal density function.
  4. There aren't too many cases to consider. First simplify the problem by looking at 6k rather than 60k. Once you solve it for 6k, just multiply by 10. Between 0 and 199 there are only 3 numbers 2, 20, 22. Between 200 and 1999 there are only 4 numbers 200, 202, 220, 222 (first hit - so the smallest for the original question is 2220). If you want more, just keep on going.
  5. If a coin came up heads 100 times in a row, I would bet on heads for the next flip. Seriously, 100 heads in a row is a strong indication that there is trick somewhere, like a two headed coin.
  6. All the entries in the matrix for T are 1. Does that help?
  7. http://en.wikipedia.org/wiki/Pyrokinesis See above - it looks like it is only fiction.
  8. The periodic table is based on the number of electrons, which equals the number of protons, for that element. Therefore all isotopes of a given element have the same number of protons and differ in the number of neutrons.
  9. mpeg files are videos encoded in a particular way. There are tools to find files when given parts of the name (such as avseq.dat). Try the following: http://www.snapfiles.com/get/everything.html I use it often.
  10. It depends on the composition of the material.
  11. What are "bare particles"? Positrons certainly exist - PET scanners!
  12. An interesting aside is Cerenkov radiation, where particles going close to the speed of light enter a medium, where the speed of light is slower than the particle speed. The particle will give off radiation in a shape that resembles the shock waves off a supersonic aircraft.
  13. The nucleosynthesis occurred for T > 500 MK (NOT <). The cosmic abundance of FREE neutrons is 0.
  14. The earliest date for an astronomical end of life on earth is about one billion years when the sun will be so hot that water on the earth would boil off.
  15. I will go out on a limb and assume that physicists that analyze the big bang aftermath take into account objections you have raised (assuming they are valid). A lot has happened since 1948.
  16. For baryons the general idea is that there are decay processes which are slightly different for anti-matter as compared to matter. These seem to fall in category of CP violation. There are no such processes for electrons or positrons.
  17. Question for Spyman. How does the description you gave (about baryon asymmetry) lead to the excess of electrons?
  18. After the big bang pair production resulted in (among other things) positron-electron pairs. Positrons do not decay, so they can be removed only by annihilation with electrons. Where did the surplus electrons come from?
  19. I believe quantum theory makes it impossible.
×
×
  • Create New...

Important Information

We have placed cookies on your device to help make this website better. You can adjust your cookie settings, otherwise we'll assume you're okay to continue.