[LEAPSECS] Keeping the day constant

Tom Van Baak (lab) tvb at leapsecond.com
Sun Jul 24 06:35:30 EDT 2011


There are two separate issues here, accuracy and stability.

1) To make Earth more accurate and better match the SI second you need a one-time increase in rotation rate. This rate correction is parts in ten to the 8th. Energy goes as the square of rate. See Earth energy here:

This would eliminate the immediate need for leap seconds.

2) To make Earth more stable and better follow the SI second you would need to dynamically increase or decrease the rotational rate to exactly compensate for ever present internal and external perturbations. This is much harder because your energy requirements are now signed and a function of time, with many Fourier components. To appreciate the variations see phase, frequency, and Allan deviation plots of earth:

This would permanently eliminate the need for leap seconds.

3) One final detail while you're doing (1) and (2) above is to slightly offset the frequency over time until the phase error is zero (that is, until DUT1 = 0). At this point you would have a time and rate accurate planet.

The algorithms for these planetary manipulations are the same as those used by a GPSDO (GPS Disciplined Oscillator).


On Jul 23, 2011, at 8:55 PM, Paul Sheer <p at 2038bug.com> wrote:


> For entertainment value, has anyone ever considered

> the amount of power it would consume to keep the

> earths day exactly constant?


> It's certainly a simple calculation. Napkin and pencil anyone?


> -paul


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