I understand that the moon is slowly drifting away from the earth.  That means in our past, the moon was closer to the earth.  Thus, it's gravity would have a greater impact on the earth.  Going back four hundred million years, what impact would that have on say the tides, currents, life and evolution?
212868
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.
311657
Undoubtedly our moon has been impacted by asteroids and other objects that otherwise would have struck Earth. If the moon wasn't there, then it follows that we might be struck more frequently.
49911
A broad answer is that all life will either adapt to these changes to survive or face death and/or extinction.\n\nThe earth has always changed and will continue to change. Many of these changes can be caused (and stopped) by man..for example reducing pollution that could be contributing to global warming. Most changes, however, are due to forces outside our control or contribution. \n\nClimate changes aren't necessarily under our control or prevention. There is a complication. The Earth's orbit is very close to being a perfect circle, but not quite. It is somewhat elliptical, which means that the distance between the Earth and the Sun varies over the course of the year. This effect is too weak to cause the seasons, but it might have some influence over their severity.\n\nThere is another important cycle that has the potential to affect the Earth's climate; it is a 41,000-year variation in obliquity, the tilt of the Earth's axis. The obliquity varies by only a few degrees back and forth, and the current value of 23.4° is near the middle of the range. However, in respect to climates on the earth, the obliquity variation has the potential to have a fairly direct effect on seasonal extremes. After all, it is the obliquity that causes our seasons in the first place - if the Earth's axis were perpendicular to its orbital plane, there would be no seasons at all.\n\nAnother factor is our moon. Our moon has a huge influence on our life here on earth on many levels, yet it is slowly moving away from us. It also is a factor of keeping the tilt of the earth's axis from taking bigger variations than it does now. As it moves farther away, the "wobble" will likely become much larger and the changes in climate on a much larger and more frequent time frame.\n\nWhen one takes into account the possibility of asteroid impacts, the immediate and long-term effects caused by plate tectonics, and many MANY more changes in our earth that are beyond human control, we see that human-influenced global warming is only a small piece of a very large changing earth puzzle. (I mention this not to say that global warming isn't a very important topic to teach, but to stress that the other causes of climate changes should be taught as well. Most school-aged children tend to think if we simply address the burning of fossil fuels there will be no climate changes on earth.)\n\nThe changes I have mentioned here are earth/space science topics. Many other changes occur on earth that are usually covered in life science classes. Hope this at least gives you some ideas to explore and research further.
554429
Nice idea.... but there is a BIG hole in your theory:\n\nThe moon broke off from the earth somewhere between 3.5 and 4.5 billion years ago.... i.e. the Hadean... the more specific name for the earlier Precambrian.\n\nPangaea didn't even begin moving together until 1.1 billion years ago, and wasn't together as one continent until about 500 million years ago.... during the Permian.\n\nOh... and tectonic plate movement is a result of thermal flows in the mantle.\n\nPangaea has nothing to do with the moon, sorry to say.
220043
Neat Question!!!!\n\nHere's your answer:\n\nIf the Moon disappeared then the tides would reduce in strength by about two thirds. There would still be tides, because the Sun causes tides, too (see the Conjunctions Page). \n\nThe Moon keeps the angle between the rotation axis of the Earth and the plane of the orbit of the Earth within a fairly narrow range, so that the strength of the seasons cannot differ too much from its current value. If the Moon disappeared, then the inclination of the rotation axis of the Earth would vary much more over periods of thousands of years and could get much further away from the upright position, with corresponding greater differences between summer and winter, and hence with great influence on the climate, such as Mars has experienced (without any large moon). See http://adsabs.harvard.edu/cgi-bin/nph-bib_query?bibcode=1993Natur.361..615L, http://adsabs.harvard.edu/cgi-bin/nph-bib_query?bibcode=2002A%26A...384..689E and http://arxiv.org/abs/astro-ph/0112399 (for http://adsabs.harvard.edu/cgi-bin/nph-bib_query?bibcode=2001EM%26P...85...61B). \n\nI've heard of kinds of animals that synchronize some rhythms of their lives with the phases of the Moon, and the sudden disappearance of the Moon could cause trouble for them. I believe I've heard of some kinds of turtles that come to lay their eggs on the beach at a certain Full Moon, and that the nightlife of deer and similar animals takes the phase of the Moon into account. In any case, fishermen and hunters seem to take the phase of the Moon into account, but perhaps that is because they would like to be able to see something at night. I am not a biologist, fisherman, or hunter, so I do not know the details of this. \n\nIt is highly unlikely that the Moon will just disappear. Only the very close passage of a celestial object of the size of a planet could wrench the Moon from the grip of the Earth's gravity, and such an event could also change the orbit of the Earth itself markedly, so then the disappearance of the Moon might not be the most important thing. Calculations of the future of the orbits of the planets show that such an event will not happen during the coming thousands of millions of years (at least not with one of the other planets of our Solar System as the disturbing object). See http://adsabs.harvard.edu/cgi-bin/nph-bib_query?bibcode=2002MNRAS.336..483I and http://adsabs.harvard.edu/cgi-bin/nph-bib_query?bibcode=1996CeMDA..64..115L.
131595
Early speculation proposed that the Moon broke off from the Earth's crust due to centrifugal force, leaving an ocean basin (presumed to be the Pacific) behind as a scar. This concept requires too great an initial spin of the Earth and the presumption of a Pacific origin is not compatible with the geological standard model, the theory of plate tectonics. Others speculated the Moon formed elsewhere and was captured into its orbit. Two of the other theories include the coformation or condensation theory and the impact theory, which speculates that the Moon formed from the debris that resulted from a collision between the early Earth and a planetesimal.\n\nThe coformation or condensation hypothesis posits that the Earth and the Moon formed together at about the same time from the primordial accretion disk, the Moon forming from material surrounding the coalescing proto-Earth, similar to the way the planets formed around the Sun. Some suggest that this hypothesis fails to adequately explain the depletion of iron in the Moon.\n\nRecently, the giant impact hypothesis has been considered a more viable scientific theory for the moon's origin than the coformation or condensation theory. The Giant Impact theory holds that the Moon formed from the ejecta resulting from a collision between a very early, semi-molten Earth and a planet-like object the size of Mars, which has been referred to as Theia or Orpheus. The material ejected from this impact would have gathered in orbit around Earth and formed the Moon. This hypothesis is bolstered by two main observations: First, the composition of the Moon resembles that of Earth's crust, whereas it has relatively few heavy elements that would have been present if it formed by itself out of the same material from which Earth formed. Second, through radiometric dating, it has been determined that the Moon's crust formed between 20 and 30 million years after that of Earth, despite its smallness and associated larger loss of internal heat.\n\nThe geological epochs of the Moon are defined based on the dating of various significant impact events in the Moon's history. Analysis of craters and Moon rocks show that there was a late heavy bombardment by asteroids around the period 4.0 to 3.8 billion years ago.\n\nTidal forces deformed the once molten Moon into an ellipsoid, with the major axis pointed towards Earth.\n\nIn 2005, a team of scientists from Germany, the United Kingdom, and Switzerland measured the Moon's age at 4.527 ± 0.010 billion years, which would imply that it was formed only 30–50 million years after the origin of the solar system.[4]
458997
While you do assume a perfectly circular orbit and zero drag force, your phrasing of the question does *not* rule out tidal effects. \n\nThis depends on the planet's oblateness, known as its "J2 moment".  Most planets are not perfect spheres, but slightly squashed along the axis of planetary rotation.  If the planet is oblate and its rotation axis is tipped to the axis of the object's orbit, then there will be tidal forces as the object experiences a net torque between the near and far sides of the planet.  Combined with lag from material stresses, there can be a transfer of rotational momentum...remember, the moon used to be much closer to the Earth and Earth rotated much more quickly a few billion years ago.\n\nIn general, this effect causes orbits which are prograde (orbit direction same as planetary rotation direction) to slowly migrate outwards, and retrograde orbits (orbit direction opposite to planetary rotation) to migrate inwards.  This is one theory for the creation of Saturn's rings: that a retrograde moon drifted inwards until it was ripped apart from increasing tidal stresses.
420065
First off, a total melting of the ice caps would raise the oceans on the order of 10's of feet.  80% of the world's population would be displaced, including everyone in the cities of Boston, New York, Los Angeles, San Francisco, San Diego, not to mention London, Paris, Rome, Bombay, Tokyo...  Plus the ocean AND air currents that bring warm water/air to Europe and moist air to the American heartland would disappear, creating complete havoc with the world's climate.  These are not fantasy predictions or dreams of alarmists.  These predictions are based on hard facts, and it is a real problem.  Just having a "gut" feeling that "it won't be that bad" is not only unscientific, not only idiotic, but exactly the attitude that will destroy us.  (BTW, you're 100% correct - 20,000 years ago our ancestors packed up their tepee and moved 10 miles inland.  You don't pack up New York.  Life will survive, there's no indication our civilization will.)\n\nSecond, none of this will affect the moon/Earth relationship.  First, the net center of gravity will not move at all, so the gravitational forces experienced by the moon will no change.  Second, the total mass of the ocean is insignificant compared to the total mass of the Earth. (Remember, about 100 miles under the crust starts the outer core of molten rock and iron.  There is literally 100,000 times the volume of the oceans in molten rock in the outer core.  The inner core is bigger than the moon and made up of solid iron and heavier metals).  The evaporation of the oceans would not do anything to the moon/Earth relationship.\n\nThird, the forces that created the moon still hold far more influence over both the Earth and the Moon that oceans or anything like that.  The moon is getting further and further from us, at the rate of about 1.5 inches a year.  Not only that, while the Earth's gravity has caused the moon to be tidally locked with the Earth, the same is happening in reverse, just much more slowly (due to the Earth being extremely massive).  There will be a day in the future where the Earth is tidally locked with the moon.  At that point, billions of years in the future, the moon will always be in a fixed point in the sky.  The moon will have slowed the Earth so that we have an approximately 40 day "day".  And the moon will be about 50 times further away from us than it is now.\n\nIt is possible that some day in the future, the moon will move to one of Earth's Lagrangian points, and the be "stolen" by the sun.  At that point the moon will become a new "planet", or the orbit will become destabilized and, believe it or not, come crashing back to Earth in a great cycle of formation and destruction.  Long before that, however, the sun will probably swallow both of us up.
98027
Predictions suggest that the range will increase until the Earth and Moon become double synchronised, that is, both are tidally locked to one another. The Earth-Moon distance would then be about 550000km. This won't occur for something like 50 billion years. Before then, though, our Sun will have died, and both the Earth and Moon almost certainly won't even exist.\n\nThis website for answer confirmation and more info  -->http://www.madsci.org/posts/archives/apr2002/1020171327.As.r.html\n\nGod is spelled B-I-G B-A-N-G\nPBrax@netscape.com
58251
Actually only about 2/3 of the tides are from the moon's gravity, and about 1/3 are from the sun's gravity. \n\nThe reason there are about 2 high tides per day, is that the gravity field produced by the sun and the moon is not constant. The farther away from the moon you are, the less the gravity is. So water close to the moon gets pulled away from the earth (the force on the earth is less since the earth is farther away) and it gets pulled up in a pile we call a high tide. On the other side of the earth, the earth is pulled away from the water (since the earth is closer to the moon than the water on that side of the earth), leaving a pile of water on the far side of the earth, which is the other high tide. \n\nIn between these two piles of water, there are places where the water is not getting piled up. We say those places are experiencing a low tide. \n\nIt gets much more complicated than this of course. There are tides in the ground and in the atmosphere, in lakes and in rivers etc. There are places where there is one high tide a day or 3 or more or even no high tides per day (because of the response of the local area to the tidal forcing; governed by the bottom topography, coastline shape, etc). \n\nThere are high tides that are extra high because the sun and the moon line up (spring tides) and high tides that are not so high because the sun and the moon are at right angles, not working together (neap tides). There are ultra high tides when the moon is especially close (proxigean spring tides). There are effects of the other planets like Jupiter   and Mars in the tides. And so on.
548429
not likely- no matter how many humans populate the planet, we make up  a very small fraction of the total mass of the earth,which is the same as it always was, since very little material has been removed from the earth since it was formed. The tsunami didn't affect the earth's orbit, it affected the rotation of the earth around its axis(sped it up by about one-billionth of a mile per hour) but didn't change the speed at which we travel around the sun(orbit) at all.no matter how we redistribute material around the planet we only change the weight distribution of the planet by a very,very small fraction so the effect will be unnoticable. the effect on this planet from human activity of any kind is much smaller than we think- greenhouse gas levels were far higher during the age of the dinosaurs than they are now (and humans didn't exist then). the amount of iron and other minerals we have taken out of the ground accounts for about onemillionth of a percent of the total amount still there. from out in space, you can't look at the earth and see anything that would suggest we live here, except the Great Wall of China and the light from our cities at night, so how great of an impact do we really have?
313946
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.
475287
Ur additional information is correct. The moon's gravity is what causes Earth's oceans to form tides (moon's gravity vs earth's gravity). Since our bodies are composed of 80% water and a human's brain is submerged in (biological) liquids, we are affected just as well.
33834
googled to find this:\n\n"The Moon, at first, will recede further and further from the Earth, but the two bodies will continue to orbit about their common centre of gravity. Around 600,000,000 years from now, the Moon will be too far away for total eclipses to occur.\n\nHowever, this process won't continue indefinitely - as Mike Sawicki points out in his Myths About Tides and Gravity:\n\nOnce the Earth becomes tidally locked with the Moon, the solar tides will tend to slow the Earth’s rotation even more, so the day will be longer than the month and the Moon will rise in the West and set in the East. The water spheroid generated by the Sun will cause the high tide to appear earlier than the time of highest moon ... Then the tidal force of Earth on the Moon will pull the Moon into a lower orbit and eventually inside the Roche limit (18500 km), whereupon the Moon will disintegrate producing a ring round the Earth."\n\nWhatever happens, we won't be around to know!
654637
Well, if there were a zodiac sign for people born "in the house of MOON," I'd put my money on that one.\n\nThe moon has an affect on tides, and so could physically have an impact on organisms on earth (unlike constellations light-years away) and I've heard people who work in psych wards say that things get busy around the full moon.
131279
No, the apparent "phase" of the moon is relative to where you are on earth at a particular time and the moon's position in relation to the earth and the sun, it does not effect the earth's rotation.  That being said the moon has had an impact on the earth's rotation, and we can assume that it continues to exert the same gravitational forces it has through antiquity.  This isn't exactly true because the moon's orbit is actually getting larger at a rate of about 3.8 centimeters per year (negligible change)*. \n\nAs to stretching these facts to assume that it might affect the space-time continuum ever so slightly I have read several scholarly articles dealing with gravitational forces and their affect on time. Of all of these Stephen Hawking's were the easiest for me to understand and the most interesting to read.  You might want to check out his books "A Brief History of Time" and "The Universe in a Nutshell", both should be available at your local library.  Whether gravity exerted by the moon is strong enough to influence time on earth or not I’m not sure but I would assume so.  If I remember correctly the closer you are to a center of gravity the faster time passes relative to someone farther away.  The visible phases of the moon would still have nothing to do with the affect on time however.  \n\nThat was an interesting question, I hope my answer was of some use to you!\n\nRegards,\n\nArmus\n*thanks for correcting me on the orbital change Answer Guy.
133124
We would stay in essentially the same orbit around the sun and gravity on earth's surface would remain normal.\nTides would be solar-only, about 1/2 to 1/3 what we have now. (Lunar-only tide amplitude is about twice solar-only tide.) This change would cause a major adjustment to shore life and possibly to birds that travel extensively over ocean waters but would not be disastrous to land-dwellers. Loss of night-time illumination would affect nocturnal animals somewhat, but they do without moonlight for several days per month as it is. Bottom line, not a major threat.