"G=EMC^2 Glazier" wrote in message...
...

Painius I find the 3mph rate of spin of Venus most amazing Bert

I could be wrong, Bert, but i have this covered in my
mind by the Sun. Both Venus' and Mercury's rates are
mainly affected by their close relative proximity to the
Sun.

Here's how it pans out...

Mercury is so close to the Sun that one would think it
would be nearer to being "locked in" than Venus is.
And there are some astronomers who believe that
Mercury actually *is* tidal-locked to the Sun, but in a
3:2 lock instead of a 1:1 lock. This just means that
they think the reason that the ratio of the orbital
period to the rotation rate is 3/2 is because of the
highly eccentric orbit of Mercury. And so because of
this, because Mercury's orbit is somewhat elliptical,
then Mercury must be tidally locked to the Sun in a
3:2 lock.

What i think science hasn't caught up with is the
probability that the rotation rates don't just decrease
to the "lock-in" rate and then stay there.

So instead of just decreasing and locking in, what do
you suppose the rotation rates actually do?

In my mind, before the spin rate "locks in", it gets
even slower, decreases to "actual" zero rotation, and
then may begin to increase in the opposite direction.
This increase continues for a time, then begins to slow
down again. It passes through "actual" zero spin rate,
and then begins to increase again until it equals the
"lock-in" rate. Then it continues to increase for awhile
until it reaches a point where it begins to decrease
again.

These "oscillations" of spin rate and direction slowly
dampen out over time until the object actually does
"lock in" to a synchonized orbit. At this point, all that
remains of the "oscillations" are what astronomers
call "librations". The smaller object sort of "rocks" to
and fro, or back and forth, with respect to the larger
body. Our sister planet, Selene (the Moon) does this...

http://en.wikipedia.org/wiki/Lunar_libration

Mercury today rotates with a spin rate of about 58.5
Earth days, and its spin direction is the same as our
Earth. The time it takes for Mercury to make a full
orbit around the Sun is about 88 Earth days. Planet
Mercury spins in a counter-clockwise direction as you
look down on its North pole. Not all that long ago it
was thought that Mercury was tidally-locked to the
Sun, that its rotational period was the same as its
orbital period (88 days). It was a bit of a shock for
astronomers to find out that Mercury does actually
rotate with respect to the Sun.

Venus, as you know, is very different, because the
rotation rate of Venus is 243 Earth days, and Venus
orbits the Sun in about 244.5 Earth days. At first
glance, it seems that Venus is almost exactly tidal-
locked to the Sun. And if Venus were rotating in a
counter-clockwise direction like all the other planets,
then it would be almost exactly tidal-locked. But, the
spin direction is opposite that of Mercury, Earth and
all the other planets. The spin direction is clockwise
as you look down on Venus' North pole.

So my idea is that, while Mercury has probably gone
through one or more cycles of slowing to zero, then
increasing again, and will eventually slow back down
and finally "lock in" to the Sun, Venus must still very
slowly decrease its clockwise spin and then begin a
counter-clockwise direction of spin to eventually
"lock in" to the Sun.

So both planets, Venus and Mercury, are fairly close
to being tidally locked to the Sun. It probably takes
many years to note any change in the spin rates of
Mercury and Venus, but my contention is that if such
a study is ever launched by science, it will be found
that the spin rates of these two are slowly, slowly
changing.

Below is a scale showing different rotation rates in
Earth days for Venus over time...

-200 -250 -300 . . . 0 . . . +300 +250 +200
^ ^
NOW LOCK

As the number of Earth days increases, the actual
rate of rotation of Venus decreases. As you can see,
at present, Venus is rotating at minus 243 days. So
Venus would have to decrease its rate of rotation
down to zero, and then begin to increase spin in the
opposite direction until it reaches plus 225 days (the
same as its orbital period). All i'm saying is that
Venus (or any smaller body) will probably go back
and forth past the "lock" point, carried past the point
each time by the rotational momentum. With each
crossing the spin speed will "flip" closer and closer to
the "lock" point until the body finally "locks in" at the
same rotational speed (in a counter-clockwise
direction) as the orbital period.

Mercury's scale looks like this...

-150 . . . 0 . . . +150 +125 +100 +75 +50 +25
^ ^
LOCK NOW

So Mercury appears a bit closer to being tidally
locked to the Sun than Venus. It only has to slow
down to a spin period of 88 Earth days. The catch
is that this hasn't been studied as far as i know, so
it may be that Mercury has passed through the lock
point and is still increasing its rotational speed. It
might take several years of study to determine
which is the case.

If i'm right, then Venus' spin rate of almost one
complete rotation in a clockwise direction during
one complete revolution around the Sun is not at
all mysterious. It might just mean that Venus is
slowly tidal locking to the Sun, but is presently in
a retrograde spin that changes and will eventually
bring Venus closer and closer to being tidal-locked.

happy days and...
starry starry nights!

--
Indelibly yours,
Paine

P.S. Thank YOU for reading!

P.P.S. Some secret sites (shh)...
http://painellsworth.net
http://savethechildren.org
http://eBook-eDen.secretsgolden.com