[LEAPSECS] Lets get REAL about time.

[Rob Seaman]

Gerard Ashton wrote:


> For the smallest time resolution required, we might suppose that at some point in the future there might be a need to account for transmission delay from one part of a computer to another. The smallest location that I can imagine being of interest even in a future computer is the diameter of a hydrogen atom, about 0.1 nm. The time for light to travel this distance is about 3 as, or about 2^-58 s.


There is plenty of prior art to consult here on both the CS side (early Crays already minimized cable runs to mitigate light speed constraints, it is commonplace today) and on the physics side (e.g., Planck units*).  Workflow logistics and systems engineering are still needed to figure out the appropriate trade-offs for whatever purpose.

There is unlikely to be one timekeeping methodology appropriate for all purposes, for instance this amazing video:

	http://web.mit.edu/newsoffice/2011/trillion-fps-camera-1213.html

Rob
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* The Planck length is 25 orders of magnitude smaller than twice the Bohr radius (i.e., the diameter of a hydrogen atom).  The Planck time is 5.391 x 10^-44 s, FWIW.