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Re: World's noise



I am from Istanbul, Turkey. Listening to a rock is a very good idea for a project work with my 6th graders, I think. I reckon as you suggested we'll need a sensitive microphone, and a tape recorder, with a proper installation. But I don't have any idea how to use fourier analysis for the data to be collected.


BTW, I was reading the article at

http://www.jpl.nasa.gov/releases/2001/heliumwhistle.html

The first sentence nn the 5th paragrah was strange. What is temperature "nearly 1 million times colder than room temperature"?

brian whatcott wrote:
Muhsin, you have probably been following the interesting debate about
ocean tides, and the prolate shape the ocean surfaces would adopt,
if not for the many complicating factors which exist.

You will have read that not only do the gravity and spin and rotation
gradients affect the water, but also the Earth itself.

It is a short step from here to ask, can I actually hear a circadian
rhythm and its second harmonic?

This seems like the kind of adventurous earth physics experiment that
might appeal to young students: the concept is easy to grasp:
if I place a microphone in intimate contact with a deep rock formation
perhaps in a quiet mine, can I capture evidence of an earth tide?

A first step might be a tape recorder setup with a low noise pre amplifier
perhaps. You might well find that the slow grinding of the Earth flex
is not perceptible by this means.
But the next step is to collect a sound sample over a period of many days.
One would not need to sample very frequently, perhaps three times an hour.

There are college physicists who I am sure would help with analyzing
this sort of time series - a fourier analysis of 1024 such samples over a
two week period might be gratifying, to start with.
There is a possibility for a library search for prior work in this area.

Is this a project which might be of interest to your students? Would you
need help with equipment? Where are you located?

Brian W



brian whatcott <inet@intellisys.net> Altus OK
Eureka!

.