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How a particle tells time (Holger Mueller et al in *Science*)

  1. Jan 17, 2013 #1


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    Bee Hossenfelder blogged about this. Too beautiful not to share.

    The experiment was done at UC Berkeley

    Precise measurement of Compton frequency of particle

    This was published online 10 January 2013 by Science journal.

    A Clock Directly Linking Time to a Particle's Mass
    Shau-Yu Lan1, Pei-Chen Kuan1, Brian Estey1, Damon English1, Justin M. Brown1, Michael A. Hohensee1, Holger Müller1,2,*

    1Department of Physics, 366 Le Conte Hall MS7300, University of California, Berkeley, CA 94720, USA.
    2Lawrence Berkeley National Laboratory, One Cyclotron Road, Berkeley, CA 94720, USA.
    *To whom correspondence should be addressed. E-mail: hm@berkeley.edu


    Historically, time measurements have been based on oscillation frequencies in systems of particles, from the motion of celestial bodies to atomic transitions. Relativity and quantum mechanics show that even a single particle of mass m determines a Compton frequency ω0 = mc2/ ħ, where c is the speed of light and ħ is the reduced Planck constant. A clock referenced to ω0 would enable high-precision mass measurements and a fundamental definition of the second. We demonstrate such a clock using an optical frequency comb to self-reference a Ramsey-Bordé atom interferometer and synchronize an oscillator at a subharmonic of ω0. This directly demonstrates the connection between time and mass. It allows measurement of microscopic masses with 4 × 10−9 accuracy in the proposed revision to SI units. Together with the Avogadro project, it yields calibrated kilograms.
    Last edited: Jan 17, 2013
  2. jcsd
  3. Jan 17, 2013 #2
    Is this the "intrinsic periodicity" idea of de Brogle suggesting that inside the particle there was a periodic process that was equivalent to a clock? Donatello Dolce has published a few papers on this topic, but I haven't seen it much discussed elsewhere:
    On the intrinsically cyclic nature of space-time in elementary particles
  4. Jan 17, 2013 #3


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    Thank you Marcus, this is really interesting! :smile:The other day I was actually about to try to touch this issue in the thread about emergent time, but I did not feel I had thought I through enough. Very interesting, thanks again! And I think I have to read the paper bohm2 linked to as well! :smile:
  5. Jan 29, 2013 #4
    Yes. It is exactly the same. In all his papers Dolce's ansatz is that elementary particles are reference clocks and the flow of time is "ticked" by the internal clocks of the particles, depending on their kinematics. He interprets quantum mechanics from this "periodic phenomenon".

    Please discuss the idea.

    Last edited: Jan 29, 2013
  6. Jan 31, 2013 #5
    In the paper http://arxiv.org/pdf/1206.1140.pdf the Feynman Path Integral (FPI) is derived from the relativistic "periodic phenomena". Is this surprising?

    "In a cyclic geometry, such as that associated to a “de Broglie periodic phenomenon”, there is an infinite set of possible classical paths with different winding numbers that link every given initial and final configurations. Thus there are many possible classical evolutions of a field from an initial configuration to a final configuration, which can interfere. The [classical] self-interference of a “periodic phenomenon” leads formally to the ordinary FPI"

    Don't be :shy:.
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