Jump to content

swansont

Moderators
  • Posts

    54099
  • Joined

  • Last visited

  • Days Won

    302

Everything posted by swansont

  1. The charge is going to be relative, since you are moving charges from one to the other. With the device by itself, you couldn't get them both to have + charges, or both have - charges. One plate or shell is going to be +, while the other will be - .
  2. Sure. You would have to do work to do the separation.
  3. Well, if you believe that we are descended from Adam and Eve, with a genetic bottleneck at Noah and his family, I would offer the HLA gene as an example. Humans have 59 alleles of this gene. The maximum you can get from two people is 4, so some mutatin' must have happened!
  4. Don't even have to go that far. The results of chemistry aren't random. Take two parts H and one part O, add a spark, and you don't get a random distribution of molecules. You get H2O. Second, it is impossible to prove anything of this sort by statistics. The probability of a past event occurring is 1. If it were otherwise, it would be trivial to prove that any given person was never born, because of all the unlikely events that occur in their ancestors' lives. --- I wonder if the original poster is one of the people who lie about science and know it's a lie, or one of the people who perpetuate the lie because they didn't have the intellectual honesty to check if the information was correct.
  5. Deleted. I've forgotten too much Chemistry.
  6. There are an infinite number of energy levels. But only one would be occupied at any given time, by a neutral atom.
  7. swansont

    Meters

    It's quite easy to say that. As pulkit said, we had already defined the meter. There is a tremendous amount of politics involved in defining standards, in part because there is a tremendous amount of commerce involved in standards. Changing a standard involves retooling machinery and recertifying traceable standards. To suggest a change for a trivial reason such as making c a round number would get you laughed out of the room of whatever BIPM committee is involved. When the meter definition was changed, the length didn't. New odometers weren't required in cars. The cm3 still represented a gram of water at a given T and P. Just the official (and best) way of defining the length was changed. Same thing with the second's definition. We didn't all have to go out and buy new clocks (unless you worked in a national standards lab, perhaps) when the definition was changed to an atomic standard.
  8. Because c is constant. It all follows from that, and the concept of simultanaeity.
  9. swansont

    Air

    To be more precise' date=' it's N[sub']2[/sub] that's more or less inert, due to the triple bond - there are few reactions that would release energy. Nitrogen compounds are important for many reactions, but AFAIK N2 is the product, not a reactant.
  10. swansont

    Air

    Go SCUBA diving and don't decompress and I think you might change your assessment of "no effect on us"
  11. "Around 600" is a rough estimate. 583 specifies the wavelength to better than 0.2%.
  12. Random events won't have a causal link. "Dice don't have memory" is one way of saying it. The fact that many people think that they do, and other misunderstandings about probability, are why casinos are money-makers.
  13. It's the smallest anything could be and be explained by currently understood physics.
  14. Take a physics class. I'm done.
  15. Neutrinos are not affected by the magnetosphere.
  16. If a nucleus has a 50% chance of decaying in 3 seconds, then the other 50% probability requires infinite time. The half-life is 3 seconds.
  17. "But in these systems the laser switches the magnetic medium by warming it." So it's not that the magnetism is affected by light, it's that it's affected by temperature. The laser just allows for very localized heating.
  18. Yes, you can do it. The dielectric constant of a vacuum is 1. Capacitance is inversely related to separation distance.
  19. Immaterial. It only matters that energy is required.
  20. swansont

    Meters

    Because that represents the speed of light. Once the decision was made to use c as the reference instead of a bar of iridium-platinum, they defined in terms of the best measurement of c, and then defined the value. It is true that the oringinal meter was defined to make the distance from equator to pole equal to 10,000 km. But they incorrectly accounted for the oblateness of the earth, so that ended up being incorrect. The wavelength, and then c definitions were adopted because the meter could be determined more accurately and precisely, just as the definition of the second was shifted to an atomic definition from being some fraction of the earth's rotation under some set of conditions. You also have the advantage that anybody with sufficient technology can realize the standard themselves, without having to go to Paris to compare with the world standard, or have the BIPM manufacture a new one for you.
×
×
  • 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.