Your Cosmic Questions Answered (Part 1)

I always wanted to understand women.

Sorry. Couldn't resist.

Can u please tell me, why we see only one side of the moon? I tried so much but couldn't find an easily understabdable answer.

My best guess is that the moon is not perfectly symmetrical around its axis. The near side (the one that we see) is slightly denser than the far side. Because of the tidal forces (gravity) between the earth and the moon, this heavier side of the moon has settled into a position as close the the earth as possible. It's kind of like rolling a marble inside a bowl. Eventually it will come to rest at the bottom, the spot closest to the earth.

Actually the moon may never have had much rotation (other than the approx one revolution per month needed to keep the same side always facing the earth), and may instead have formed under the influence of the earth-moon tidal forces. One current theory is that it was formed by the accretion of the partially molten debris ejected into space by a collision between the earth and another small planet. As the debris (think lava) was coalescing, tidal forces would have favored the denser materials clustering on the near earth side of the blob. In addition the tidal forces would have caused a tidal bulge on the near earth side as well. Now that the moon has solidified, this asymmetry has 'locked' the moon into a position where the same denser side always faces the earth.

It's not so much a density issue, but tidal coupling and the nearly identical periods of the Moon's rotation and revolution in orbit (except for small fluctuations, both are about 27.3 days) cause us to see essentially the same side of the moon. We actually observe about 55% of the entire surface. Hope this is easier to comprehend, but if not, http://www.fearofphysics.com/SunMoon/sunmoon1.html should help visualize it.

You are right that it is tidal coupling, which results in the almost identical orbital and rotational periods. I was merely trying to speculate as to the cause of the tidal coupling, which is why I suggested that the moon's mass is asymmetric with respect to it's axis, giving it a heavy side and a light side. The heavy side would be the one facing the largest local source of gravity, which is us.

If you read Zecharia Sitchin and the Sumerian cosmology (the Earth Chronicles series), the clay tablets tell a story told to us by the 'gods', and was repeated annualy in the spring festival, in a story known as the "Enuma Elish" (In The Beginning")

It says that the planet Earth used to be a much larger planet, mostly water. It had a large moon that was nearly a planet size itself. A "Wanderer" came in from outerspace, and it had 4 moons of its own. (East Wind, West Wind, North Wind, South Wind) which smashed consecutively into the mother planet, and kicked the mother planet and her moon into our current orbit. Most of the water was splashed out to mars, jupiter neptune. This also formed the Hammered Bracelet (asteroid belt) and the comets, and of course, smacked hell with our moon. (craters) The pacific ocean is the healed over scar of the missing half of our planet.

It would seem to follow that the moon, however it was originally formed, has an erratic orbit because of the disturbance to it's orbit 65000 years ago (which terminated the Jurassic period of course)

How did pre-einstein astronomers and physicists think about red shift/ blue shift of light from the stars? how did they explain it, in terms of aether?

I don't think the issue ever came up, because before we had Einstein's theories, we also didn't have any telescope/spectrometer systems around that were sensitive enough for this type of work. By the time Hubble made his discoveries of red and blue shift (remember he never explicitly claimed this meant the universe was expanding), Einstein's main contributions were already well understood.

They didn't know about it. I didn't know about it aether. He He