resonant frequency of anything

From: Paul Doherty (
Date: Tue Jan 07 2003 - 12:13:37 PST

Hi Ric

The fundamental resonant frequency (acoustical) of any onject is the
inverse of the time that it takes sound to travel across the object and
back. Or for a deformation wave to travel along the object and back.

The fundamental(lowest) resonant frequency of the earth is 1/54 minutes or
0.3 millihertz.

Was Tesla measuring the electromagnetic resonance of the earth rather than
the acoustic resonance? In that case you would use the travel time for
electromagnetic waves around the earth probably interacting with the plasma.

Paul Doherty

Date: Thu, 19 Dec 2002 10:49:44 -0600
Subject: Resonant Frequency of an Object

I am interested in the formula for finding the resonant frequency of an
object. Like say a mountain top, or a building, something of that nature.
Nikola Tesla determined that the resonant frequency of the earth is 7 Hz.
How did he go about finding that?


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