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Science

Fine Structure Time Service 13

Posted by michael from the at-the-tone,-the-constant-will-be dept.
bromoseltzer writes: "Know your universe! Our Fine Structure Time Service keeps you in touch with your atomic underpinnings."
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Fine Structure Time Service More

Fine Structure Time Service

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  • How accurate is the estimate?

    Put in an error estimate and it would be more useful.
    • The error bars are indicated on the current NIST datum. Let's put it this way - in 100 million years or so, the model's predictions should be significant using today's measurement error bars.

      It would be better to ask why we are using this functional form - predicting alpha = 0 at t = 20 M yr, for example.

      The answer is, why not?

      - The Happy Physicist

  • I'll admit that I don't know everything about math, physics, and chemistry even though I've studied them all a good deal. But anyone care to explain this constant? Why its significant? What is it used for?

    Just pointing a link to a constant isn't really telling me much.

    • The FSC is a measure of the strength of the electromagnetic interaction, or if you will, the charge on the electron. alpha = e^2/(4 pi hbar c) in Gaussian units (I think... in any case, in the "correct" units :-) As such, alpha (along with the proton and electron masses) determines everything about chemical reactions (binding energies, reaction rates, etc), about the spectroscopic properties of elements (the absorption and emission spectra), about the behavior of semiconductors, the behavior of particle accelerators, etc. It is one of the most important fundamental "constants" in particle physics. And there has been recent data which suggests pursuasively that alpha is in fact NOT constant in time, but has changed since the very early universe.

      • No kidding.

        Shoot I need to get one of these devices next to my bed. Maybe as an add-on module for my alarm clock.

        "Good Morning the time is 09:00 am and the FSC is
        a = 0.00729735253300000002542561784
        a**-1 =137.035999765368605156268595"

        or maybe as a an add-on for my bathroom scale (also talking)

        "jeez your mass/volume ratio is high today, you overcharged mass of electrons"

        --
      • There is strong evidence that the FSC is not a "constant" that has/is changing, but a function. Look for yourself here [mrti-usa.com].
    • anyone care to explain this constant? Why its significant? What is it used for?

      If you follow the links provided on the given page, you'll soon reach here [nist.gov] (claims to be for non-experts).

      • Unfortunately, that site seems to be for non-experts who also understand all kinds of crazy math, of which I don't even know the name.
        • Unfortunately, that site seems to be for non-experts who also understand all kinds of crazy math, of which I don't even know the name.

          As far as I can tell, the Fine Structure Constant can't be explained without recourse to big mathematical things. It's just one of those things that's easier to describe in its effects (as an earlier poster [slashdot.org] has done) than to give an explanation of what it is [treasure-troves.com].

        • Okay, as I am a physicist I can tell you how we handle such cases: Every time I encounter a word/concept which I don't know I just replace it with "gizmo" and read over it. So, e.g. the sentence
          According to quantum electrodynamics (QED), the relativistic quantum field theory of the interaction of charged particles and photons, an electron can emit virtual photons that can then emit virtual electron-positron pairs (e+, e-).
          turns into
          According to gizmo (gizmo), the relativistic gizmo theory of the interaction of charged particles and gizmos, an electron can emit virtual gizmos that can then emit virtual electron-gizmo pairs (e+, e-).
          which is not that bad - you get the key message. Of course, if it reads
          According to gizmo (gizmo), the gizmoic gizmo theory of the gizmoation of gizmoed particles and gizmos, an gizmo can emit gizmoal gizmos that can then gizmo gizmoal gizmo-gizmo pairs (e+, e-).
          you have a problem. In that case, skip the sentence and carry on. If you are lucky it wasn't of key importance for understanding the concept anyway.

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