TeaTime wrote:
"Weatherlawyer" wrote in message
oups.com...
First in browsing the astronomy groups I came upon sci.astronomy only
to find it is no longer in use. Or is it just Google no longer posting
to it? How come it went out of fashion, anyone know?
And now to business:
I was trying to find out more about the Chandler Wobble on here "only
to find" no one has mentioned it in several years.
May I take you are all as much in the dark about it as I am?
---
Very interesting topic, Weatherlawyer.
For those unfamiliar: the Chandler Wobble is a phenomenon discovered by
American astronomer
Why so modest?
USAan astronomer Seth Chandler before the turn of the century. It
describes a small irregularity in the Earth's rotation whereby the Earth's
axis 'wobbles' slightly, a bit like that of a spinning top slowing down.
What is this thing with child's tops?
When was the lst time anyone saw one of them?
Is the analogy about the top of the toy or the pointy end? Does the
pointy end move or wobble? I can't remember.
Rather than spinning at a point, the north pole effectively moves in little
spirals of increasing or decreasing size, of a few metres diameter. The
magnitude of the wobble varies, almost stopping at times and becoming more
extreme at others.
Almost stopping as in reaching a "point of dwell" as might be imagined
with the declination of the moon or sun? And observed in reciprocating
engines at top and bottom dead centres under a stroboscope.
Or almost stopping as in:
""Sun, be motionless over GibŽe·on, And, moon, over the low plain
of AiŽja·lon." Accordingly the sun kept motionless, and the moon
did stand still" ?
The Jet Propulsion Lab's Dr Gross issued a statement
some 15 years ago that he believed it was all due to varying pressures at
the bottom of the oceans, caused by changing temperatures, winds and
salinity and resultant currents, etc. ... all very complicated.
And a lot less likely than the unbelievable idea that the moon has the
power to raise enough miniscule particles of water to raise a tide,
without having the same ability to raise it all the way to the moon.
More interesting still is the (unproven) theory that volcanic and seismic
activity is linked to the 6.5 year average cycle of the wobble's maxima and
minima. There is certainly some statistical evidence to suggest that there
is a degree of harmonic regularity to volcanic outbursts and earth/sea
quakes and one may even derive a cyclic period from bunches of peaks on the
graphs, but there is no clear synchronicity with our friendly wobble, even
allowing for lags due to the huge mass of the earth.
The list of unproven theories like that is longer than you might be
expected to believe since no one has really looked at the subject as
far as I know.
Give us endless articles about life on Mars and you can spend as much
time and money developing rockets and satellites and etc...
I wonder what the infrastructure for something like that would cost,
compared to something a lot more useful and even more mundane.
References:
http://www.abc.net.au/science/news/e...ish_153343.htm
http://www.michaelmandeville.com/pol...relations2.htm
Hey, I followed those two Google links too.
I also looked at the
http://hpiers.obspm.fr/ site
Euhau, euhau, euhau! Zose sheez ateuing Fronjemane; zey are not zo
zurrendeure monkayz etr? Non?