[time-nuts] Q/noise of Earth as an oscillator

David davidwhess at gmail.com
Fri Jul 29 04:29:27 EDT 2016

On Wed, 27 Jul 2016 15:15:48 -0400, you wrote:

>On 7/27/2016 10:04 AM, time-nuts-request at febo.com wrote:
>> Exciting the Earth with a new frequency (and an adeguate amount of
>> energy) sets a new rotational speed: you cannot retune a (for example)
>> quartz crystal in the same way...
>Sure you can. Spin it at 100 RPM, or 1000, RPM or even 25000  RPM... :)
>Interesting conversation. I tend to agree the earth is not a classic 
>harmonic oscillator. Energy is not exchanged between different storage 
>mechanisms. It's rotational period has no natural harmonic frequency. 
>i.e. rotational period could be anything.
>However I also agree it exhibits characteristics of other items that Q 
>can be calculated for. Rate of slowing, loss of energy per cycle, etc.
>And since the definition of Q is varied and used quite widely, it seems 
>Q is also appropriate here.
>Maybe Earth is a special case since after all it DID give us the second, 
>and we DO set our atomic clocks to IT every 6 to 12 months...
>...now I'll be thinking of this all night...  ...I think Tom is just 
>toying with us now...

Capacitors and inductors have an associated Q while lacking a resonate
frequency except for parasitic elements.  Their Q increases with
frequency up to a point; does that apply to a spinning body?  I guess
it depends on the loss mechanism.

If you used the Earth's rotation as part of a harmonic oscillator,
what would limit the Q?  All the sloshing fluid, physical
displacement, and mechanical hysteresis add up to energy lost per

This seems like one of those fun physics problems where you start with
a bunch of seemingly unrelated pieces of numerical data and calculate
the mass of the Milky Way.

More information about the time-nuts mailing list