What would the gravitational effects of the moon play on life four hundred million years ago?
469805
Not much.  The moon was not significantly that much closer to the Earth only 400 million years ago.  As such, while the tides would have been slightly higher and lower, there would not have been enough of a difference to make anything different for life.\n\nIn short four hundred million years ago the gravitational effects of the moon played the exact same roll they do today.
5176
It would take something very huge to alter the moons position..chances are that something that huge would destroy earth as well..but ..for now...the moon ..is getting further away from us.. at a rate of approx. 4 inches ..a year.
443155
First off, the rotation around it's axis speeds up. \nThe faster the speed, the more "rugby like" a sphere apears . \nThe moon would be orbiting it in a more eleptical orbit\nIts own orbit perhaps would be altered and become more eliptical. A more eliptical orbit results in us getting out of the "life zone" thus ending life on the planet throughout the course of several years... \n\nhmm... HOWEVER, if it was a Vertical Rugby ball then its the total opposite, for it would be rotating around the two pointy sides rather than the flat ones.  Interesting, I'm going to start making models !
1101666
It depends on how large the impactor was and how fast it was moving. A large impact would make a new and very large crater on the moon. A couple days later we would have a great meteor shower display here on earth as pieces impacted our atmosphere.\n\nIf it was large enough to shatter the moon you could end up with several large pieces orbiting separately. Again, it depends on the size and speed of the impactor. If you broke it up sufficiently, you could form a ring.\n\nThat brings us back to what would then happen on earth. The obvious answer is the tides would be much smaller. We would still have tides, but they would be: (1) Caused by the Sun and therefore smaller. (2) They would come at roughly the same time each day.\n\nThis would affect a good deal of the marine life that depends on the tidal changes.\n\nLighting would also change. Reproductive behaviors in a number of animals are goverened by the moon's cycle. It is not known how much the moon's absence would change this.\n\nThe days would not grow longer as someone suggested. The opposite is true as the friction overcome in producing the tides takes energy. That energy is coming out of the earth's rotation and the moon's orbiting around the earth. The moon is slowly moving farther away and the earth is slowing down so the days are getting longer. Of course, this is an extremely slow process and you are not going to notice any change. The moon's absence would mean it wouldn't take place.\n\nEarthquakes would not be affected. They are caused by plate tectonics, which is independent of the moon.\n\nIf you are interested in the moon, try\nhttp://groups.yahoo.com/group/lunar-obse...\n\nHope this helps\n\nChuck
422733
yes it would affect the earth because it would disrupt our tides and all of our weather would either become very extreme or nonexistent also we wouldn't have a moon for any one else to visit and then we wouldn't be able to go to anywhere but the earth .
52820
The gravitational pull on the moon is 1/6 that on Earth.  Note that on the Moon only your Weight (Pulling force of planet,etc) changes and not your Mass (Measure of amount of matter in an object).  So if your Mass is 100lb (approx 45kg) on Earth, it would still be 100lb on the Moon.  \nHowever your Weight changes from being 450N (450 newtons using the equation Weight = Mass x gravitational field strength on earth which is taken as 10N/kg) on Earth to 75.2N on the moon (1/6 that on Earth where g = 1.67N/kg)
229254
Around 3.5 billion years ago
855641
a long time ago, when the moon wasnt so big
802553
The real answer is that we would almost certainly not have evolved without the moon; experts give these main reasons \n\nThe stability of the earth's rotational axis---it always remains nearly 23 degrees---is due partly to the Moon's presence; without it, the Earth's axis would wobble much more violently, so that seasons would be far more severe. [This wobble would occur over thousands to hundreds of thousands of years, but that might have been enough to affect evolution dramatically.] We could even from time to time orbit on our backs like the planet Uranus!\n\nThe length of the day might have been much shorter.\n\nThere would be greatly reduced ocean tides or tidal reaches so that the development of much of marine life, and certainly the development of Amphibian and the settlement of Dry Land, would have been greatly affected, perhaps prevented.\n\nAs for the present, our civilization might find it hard to adapt to a sudden withdrawal of the Moon, but could learn to cope with a slow drifting away---which is in fact occurring at a rate of about 3 cm/year. \n\n\nThat is the "short" answer, but if you want more information, this website explains in detail, but in easy terms how the moon and earth interact and so you can conclude further for yourself what the planet would be like without it.\n\nhttp://www.astronomytoday.com/astronomy/earthmoon.html
63349
Yes, Earth's rotation gradually slows down due mainly to tidal friction caused by the gravity of (mainly) the Moon (since it's very close) and the Sun (since it's very massive). It was as low as 10 hours 3 to 4 billions of years ago.
1026743
4 500 000 000 years, given or taken a few.
295462
Anything with mass has gravity - the bigger the mass the bigger the gravity.  The moon which is quite small compared to earth has much less gravity - look at the footage of the sapcewalks.  Larger planets such as Jupiter or Saturn have much higher gravity - probably so much so that you'd be crushed under your own weight.\n\nThe moon's gravity affects the earth (most noticably in the tides) and to a much lesser extent the other bodies in the solar system affects the earth.
410440
Assuming life on earth still existed and that water\ncould still be found (not all frozen), the tides \nwould be smaller, because the Moon influences the\ntides about 90% but the other 10% influence comes\nfrom the Sun's gravitational force... That's why\nthe tides are higher at New Moon and Full Moon, \nbecause both the Moon and Sun are pulling along\nthe same line, whereas at first quarter and last\nquarter Moon, the tides are relatively lower, \nsince the Sun and Moon's gravitation somewhat\ncancells each other out
650556
First the ocean tides would lessen by about 66% since the Moon effects the gravity of earth.  The sun causes the other portion of tides, so tiedds would continue, just a lesser amount.  After about 1,000 years the season would change because the moon keeps the earth's rotation axis and the plane of the orbit of earth within a narrow range.  That range would widen and there would be a more significant difference in the climate between summer and winter.  Many animals use the sequence of the moon for their life cycles (laying of eggs of the turtle, for instance).  So, these animals' life cycles would change, possibly causing extinction.  Additionally the moon provides nighttime light which many animals depend on for hunting as well as farmers depend on for harvesting.
1150339
It'd depend more on what forced the moon out of it's typical orbit.  If something slowed the moon then the moon would gradually fall to earth be a relatively smooth landing  probably destroying a lot of disruption where it lands and over most of the planet not to mention throwing off the equal libream of our axis causing the to rotate and wobble in random patterns until balanced again.  If it was forced very quickly it could shatter the planet, the planet would most likely pull back together but you could kiss all life goodbye, except very resilient bacteria. Refer to Mimas a moon that orbits around Saturn, also referred to as the death star moon.  Hope I helped
709333
The moon's gravity causes tides, which is not quite the same thing. A "tidal wave," or tsunami, is caused by an earthquake.\nBecause distance is an central factor in gravity, the part of the global ocean that is closest to the moon at any given moment will bulge outward ever so slightly toward the moon. On the opposite side of the earth, the water farthest away from the moon will bulge in the opposite direction, being less influenced by that same gravity. Those two regions will then experience high tide. Halfway between them will be the two areas of low tide.\nAs the earth rotates, each part of the surface eventually passes through each of these gravitational regions, thus experiencing two high tides and two low tides each day.\nThe sun has some influence on tides as well, but its distance from the earth lessens its impact. However, when the sun, moon and earth are in alignment, the combined forces result in unusually high and low tidal patterns.
318949
Depends on what period during the Precambrian.  \n\nVery early in the Precambrian, the atmosphere would have been unbreathable.  It also would have been unsurvivably hot.\n\nLater, it would have poured rain constantly for about a million years or so just after the Earth cooled enough for water vapour to become liquid water, hit the hot Earth and get vapourized again.\n\nBut after live began to evolve, and photosynthesis created the oxygen atmosphere we know and love today, it probably would have been quite nice to visit.\n\nAs long as you weren't there on one of the occasions when a giant asteroid hit the Earth (about every 100 million or so), or during one of the period ice ages (one ice age about 800 million years ago appears to have covered the entire planet in ice - although eccentricities in the Earth's orbit may have created a rotating seasonal hole of open water near the Equator).\n\nThe biggest dangers would have been boredom and starvation.\n\nOn land there would be no life at all for several hundred million years at least.  Not even lichen or moss.  No plants, no insects, nothing.  Same with the oceans.  Maybe a few mats of floating algae and some squiggly worms in the mud.  Nothing else, not even a crab or jellyfish.  Certainly nothing that could eat you.\n\nBecause there was no life on land, the soils would have been very very poor in organic content.  Any plants you brought with you would have difficulty growing unless you brought plenty of fertilizer and nutrients, so I hope you brought lots of Twinkies.\n\nSome of the scenery would no doubt be spectacular.  Huge expanses of open terrain without a single plant, bird or bug to make a peep.\n\nSo a very nice to place to visit, but you wouldn't want to live there.