17 Jul 07
Originally posted by sonhouseThe "fullness" of the Moon has zero relation to the gravitational effect it has on the Earth as far as I know. Can you elaborate?
Yeah but when?
One other thing will happen, like Mars, whose tilt can go from almost north south to like east west, that is to say, the north or south pole pointed at the sun. The moon keeps the earth from making major tilts, like ours now at about 23 degrees is about as serious as it can tilt with el luna nearby. Don't forget, tides do more than water. It ...[text shortened]... r on earth. However, here is another sub-puzzle: What will happen to the earth way before that?
18 Jul 07
Originally posted by AThousandYoungDuring a full and new moon the gravitational forces of the moon and the sun work together on the tides to cause spring tides. When the moon is in its quarter phases they oppose each other causing a smaller difference between low and high tide, called neap tides. Spring and neap tides are about 20% higher or lower then average. The Proxigean Spring Tide is a rare, unusually high tide. This very high tide occurs when the moon is both unusually close to the Earth (at its closest perigee, called the proxigee) and in the New Moon phase (when the Moon is between the Sun and the Earth). The proxigean spring tide occurs at most once every 1.5 years.
The "fullness" of the Moon has zero relation to the gravitational effect it has on the Earth as far as I know. Can you elaborate?
18 Jul 07
Originally posted by sonhouseIn about 2 billion years the seas will boil, which will stop the entire process - there won't be any friction. A little while later (another 1.5 to 2 billion years) the sun will become a red giant, but the earths orbit will have increased to around 1.3 AU's (by the same process that's causing the moon to recede from the earth), so it will probably not be absorbed. Shortly after that the Andromeda Galaxy and the Milky Way will collide which will probably be bad news for the orbital stability of the solar system. Depending on the values of various physical quantities to do with the cosmological constant in 20 billion years the universe will expand so rapidly that individual particles will be causally disconnected and nothing will happen after that because everything will be too far away from everything else.
Yeah but when?
One other thing will happen, like Mars, whose tilt can go from almost north south to like east west, that is to say, the north or south pole pointed at the sun. The moon keeps the earth from making major tilts, like ours now at about 23 degrees is about as serious as it can tilt with el luna nearby. Don't forget, tides do more than water. It ...[text shortened]... r on earth. However, here is another sub-puzzle: What will happen to the earth way before that?
29 Jul 07
Originally posted by rlbatezA red giant doesn't have enough gravitational pull to keep itself tight, while a white dwarf has a much larger mass and compresses itself. So the smallish Sol will become a red giant because it doesn't have enough mass to become a white dwarf.
I thought the sun was too small to become a red giant? Shouldn't it just become a white dwarf star due to its relatively small mass??
Also if the galaxys are moving away from each other what would cause the Andromeda galaxy to 'visit' our- milky way- galaxy?
Anyone?😉
29 Jul 07
Originally posted by GastelBut that's only after it's burned off alot of fuel.
A red giant doesn't have enough gravitational pull to keep itself tight, while a white dwarf has a much larger mass and compresses itself. So the smallish Sol will become a red giant because it doesn't have enough mass to become a white dwarf.
That's not going to happen for a few million years at least.
30 Jul 07
Originally posted by rlbatezThe galaxies move away from each other as a whole but llocally some of them can converge. It's like the big bang set everything in motion in an expansive way but if the galaxies are near enough to each other their gravitational attraction can be enough to overcome the general behaviour.
Also if the galaxys are moving away from each other what would cause the Andromeda galaxy to 'visit' our- milky way- galaxy?
Anyone?😉
A very poor analogy: imagine that you're in a mall and a bomb goes off. Naturally people will begin to scatter away but if you were in the mall with your sons or any loved ones you'll almost certainly run towards them to protect them.
Ps: What a crappy analogy 😞
31 Jul 07
Originally posted by znshoYou can read all about tidal locking here:
Presumably, the rate of moving away from the Earth is increasing all the time. Can anyone explain in more detail?
http://en.wikipedia.org/wiki/Tidal_locking
What a red giant and a white dwarf are here:
http://en.wikipedia.org/wiki/Red_giant
http://en.wikipedia.org/wiki/White_dwarf
Various possible fates for the universe (a big crunch is probably ruled out as the expansion of the universe appears to be accelerating):
http://en.wikipedia.org/wiki/Big_crunch
http://en.wikipedia.org/wiki/Big_Freeze
http://en.wikipedia.org/wiki/Big_Rip
And here are some time lines for what has happened and what is expected to happen:
http://en.wikipedia.org/wiki/Graphical_timeline_of_the_Big_Bang
http://en.wikipedia.org/wiki/Graphical_timeline_of_our_universe
http://en.wikipedia.org/wiki/Graphical_timeline_from_Big_Bang_to_Heat_Death