1. Standard memberPalynka
    Upward Spiral
    Halfway
    Joined
    02 Aug '04
    Moves
    8702
    16 May '09 10:43
    Originally posted by KazetNagorra
    I don't see the conflict - if you regard a black body at t = 0 and wait for a photon to be emitted at exactly 744 nm it won't happen. The wavelength of an emitted photon will contain an infinite string of random numbers in decimal representation and even though the infinite string of all zeros is not any less likely than any other particular infinite st ...[text shortened]... safe to say a black body will never emit a 744 nm photon (or "almost sure", if you insist).
    The conflict is that adam's statement was perfectly correct and precise.

    Your corrections are therefore out of place and, worse, are more imprecise with the wording.

    It's false to say that events of probability zero won't happen. It's as simple as that. In fact, all future wavelength emissions have probability zero of happening, yet they will happen.
  2. Standard memberadam warlock
    Baby Gauss
    Ceres
    Joined
    14 Oct '06
    Moves
    18375
    16 May '09 15:001 edit
    Originally posted by KazetNagorra
    You don't analyze the case L = 0, since that doesn't allow any EM mode. You start with some finite L, which allows wavenumbers (in 1D, generalization to 3D is straightforward) k = 2*pi*n/L with n integer. Taking the limit of L to infinity allows a continuum integral formulation appropiate for thermodynamics, and allows photons will arbitrarily low energies instead of the lower limit corresponding to k = 2*pi/L in the finite L case.
    Shame on me for writing L=0. But good thing you understand what I meant.

    By the way: wrong answer.

    Read up on probability theory, statistical mechanics, and quantum mechanics. 😉
  3. Germany
    Joined
    27 Oct '08
    Moves
    3118
    16 May '09 15:24
    Originally posted by adam warlock
    Shame on me for writing L=0. But good thing you understand what I meant.

    By the way. wrong answer.

    Read up on probability theory, statistical mechanics, and quantum mechanics. 😉
    I will, for the next five years or so.
  4. Standard memberadam warlock
    Baby Gauss
    Ceres
    Joined
    14 Oct '06
    Moves
    18375
    16 May '09 16:01
    Originally posted by KazetNagorra
    I will, for the next five years or so.
    How long is your degree? Or are you already counting with a future Masters/PhD ?
  5. Germany
    Joined
    27 Oct '08
    Moves
    3118
    16 May '09 17:52
    Originally posted by adam warlock
    How long is your degree? Or are you already counting with a future Masters/PhD ?
    I am currently getting my master's degree and intend to get a PhD position.
  6. Standard memberadam warlock
    Baby Gauss
    Ceres
    Joined
    14 Oct '06
    Moves
    18375
    17 May '09 00:25
    Originally posted by KazetNagorra
    I am currently getting my master's degree and intend to get a PhD position.
    In this case you really need to, at least, study those things.

    I mean if you want to be a PhD in physics and can't even interpret probabilities you really need a lot of catching up to do.
  7. Germany
    Joined
    27 Oct '08
    Moves
    3118
    17 May '09 09:50
    Originally posted by adam warlock
    In this case you really need to, at least, study those things.

    I mean if you want to be a PhD in physics and can't even interpret probabilities you really need a lot of catching up to do.
    Maybe.
  8. Joined
    11 Nov '05
    Moves
    43938
    17 May '09 15:28
    There has been a sub-discussion in this thread about probability zero. On argument states that "events of probability zero may happen". If find this impossible.

    An event that has probability zero cannot happen!

    If p=0 can happen, than anything can happen.
    The probability that the sun is gone and been gone from the time Earth was into being has zero probability. It's there, we see it, we can measure it, th whole life on earth is dependant that it's there. If someone says that even if the probability is zero that it's gone, it might be that the suns is gone, I will object.
    If the probability that the sun is gone tomorrow, is zero, then it will surely be there tomorrow. If it's even the slightest is > zero, then it might be gon tomorrow, but when b=0, and exactly =0, then it will be there tomorrrow too, rely on that.
    If we calculate that the probability of that the sun is gone tomorrow is exactly zero, and it actually isn't there tomorrow, then we have made an error in our calculation.

    Bottom line: An event that has probability zero cannot happen!
  9. Standard memberPalynka
    Upward Spiral
    Halfway
    Joined
    02 Aug '04
    Moves
    8702
    17 May '09 15:38
    Originally posted by FabianFnas
    There has been a sub-discussion in this thread about probability zero. On argument states that "events of probability zero may happen". If find this impossible.

    An event that has probability zero cannot happen!

    If p=0 can happen, than anything can happen.
    The probability that the sun is gone and been gone from the time Earth was into being has zer ...[text shortened]... ror in our calculation.

    Bottom line: An event that has probability zero cannot happen!
    Physicists these days don't seem to understand anything of probability theory.
  10. Standard memberPalynka
    Upward Spiral
    Halfway
    Joined
    02 Aug '04
    Moves
    8702
    17 May '09 15:411 edit
    Let's do a basic exercise, shall we?

    Take a normal distribution, what is the probability that you draw any individual real number x?

    Edit - Let's label this probability P(X=x)
  11. Joined
    11 Nov '05
    Moves
    43938
    17 May '09 16:23
    Originally posted by Palynka
    Let's do a basic exercise, shall we?

    Take a normal distribution, what is the probability that you draw any individual real number x?

    Edit - Let's label this probability P(X=x)
    You tell me, you are arguing your line, you tell me.
  12. Standard memberPalynka
    Upward Spiral
    Halfway
    Joined
    02 Aug '04
    Moves
    8702
    17 May '09 16:33
    Originally posted by FabianFnas
    You tell me, you are arguing your line, you tell me.
    P(X=x) = 0 for all x in the set of all reals. Do you agree, Mr. "Physicist"?
  13. Standard memberPalynka
    Upward Spiral
    Halfway
    Joined
    02 Aug '04
    Moves
    8702
    17 May '09 16:35
    I wonder how long will it take for Fabian to realize he's again wrong and start shrieking about being stalked.
  14. Germany
    Joined
    27 Oct '08
    Moves
    3118
    17 May '09 16:48
    Originally posted by Palynka
    Physicists these days don't seem to understand anything of probability theory.
    Admittedly it's not my field of expertise. They don't teach it much.
  15. Standard memberadam warlock
    Baby Gauss
    Ceres
    Joined
    14 Oct '06
    Moves
    18375
    17 May '09 16:492 edits
    Originally posted by Palynka
    Physicists these days don't seem to understand anything of probability theory.
    😠

    Kazet is a physicist to be and still has enough time to steer away from the dark side of the force.

    Is Fabian a physicist? I predict that event to have a 0 probability. 😉

    But the fact that Kazet, a physics student, has a very weak grasp of probability theory strike me as very odd.
Back to Top

Cookies help us deliver our Services. By using our Services or clicking I agree, you agree to our use of cookies. Learn More.I Agree