effects of moon on earth

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confuseddotcom

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I have been in discussions with friends and was wondering what effect does the moon have on the rotation of the earth on its axis??<br /><br />Thanks <br /><br />BOB.
 
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Boris_Badenov

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Orbit and relationship to Earth <br />Most of the tidal effects seen on the Earth are caused by the Moon's gravitational pull, with the Sun making only a small contribution. Tidal effects result in an increase of the mean Earth-Moon distance of about 3.8 m per century, or 3.8 cm per year.[48] As a result of the conservation of angular momentum, the increasing semimajor axis of the Moon is accompanied by a gradual slowing of the Earth's rotation by about 0.002 seconds per day per century.[49]<br /><br /> <div class="Discussion_UserSignature"> <font color="#993300"><span class="body"><font size="2" color="#3366ff"><div align="center">. </div><div align="center">Never roll in the mud with a pig. You'll both get dirty & the pig likes it.</div></font></span></font> </div>
 
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alokmohan

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Tidal effect is not only in earth moon system.Once you fall in black hole you are infinitely stretched and sqeezed and you become very long and very thin.If you visit a black hle make sure you dont fall in.Dont forget me I am black hole specialist.
 
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willpittenger

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In addition the effect metioned by Boris, the Earth's rotation axis changes less than it would if we had no Moon (think Venus) or only small moons like those that Mars has. <div class="Discussion_UserSignature"> <hr style="margin-top:0.5em;margin-bottom:0.5em" />Will Pittenger<hr style="margin-top:0.5em;margin-bottom:0.5em" />Add this user box to your Wikipedia User Page to show your support for the SDC forums: <div style="margin-left:1em">{{User:Will Pittenger/User Boxes/Space.com Account}}</div> </div>
 
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MeteorWayne

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What does that have to do with the earth-moon system? <br /><br />Answer: Nothing. <div class="Discussion_UserSignature"> <p><font color="#000080"><em><font color="#000000">But the Krell forgot one thing John. Monsters. Monsters from the Id.</font></em> </font></p><p><font color="#000080">I really, really, really, really miss the "first unread post" function</font><font color="#000080"> </font></p> </div>
 
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MeteorWayne

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A large part of the angular momentum of the earth-moon system is contained in the moons motion and mass.<br /><br />The tidal forces of the moon stabalize the axis of rotation of the earth by tugging on the mass closest to it, near the equator. Hence the earth's obliquity (tilt of the axis) only changes by about 2 degrees (from 22.5 to 24.5 degrees); wheras Mars, whose moons have almost no mass allow it to tilt from zero to 60 degrees.<br /><br /> <div class="Discussion_UserSignature"> <p><font color="#000080"><em><font color="#000000">But the Krell forgot one thing John. Monsters. Monsters from the Id.</font></em> </font></p><p><font color="#000080">I really, really, really, really miss the "first unread post" function</font><font color="#000080"> </font></p> </div>
 
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R1

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at a slowing of 0.002 seconds per day per century (0.73 sec./year per century)<br />then the days the dinousaurs saw must have been less than 20 hours? how would I calculate this,<br />since I used 365.25 in my calculator, yet millions of years ago a year also had more days.<br /><br />No big deal, I'm not expecting anyone to spend hours trying to figure this out, unless it's already<br />known how short the days must have been back then, but I wouldn't be surprised if the day and night at the <br />equator were barely over 9 hours long each back then.<br /><br /> <div class="Discussion_UserSignature"> </div>
 
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adrenalynn

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Just doing some off-the-cuff numbers:<br /><br />Middle of the Jurassic was somewhere about 160M years ago, IIRC.<br /><br />160,000,000 * 0.73 = 116,800,000 seconds / 60 / 60 / 24 ~= 1,352days of drift over the course of 160M years.<br /><br />Assuming your given is correct, I calculate:<br /><br />24-((1352 /160000000) *365.2524 *24*60) = 19.556hrs /day in the height of the Jurassic, give or take my rounding errors.<br /><br />I am a bit sleepy, as this is exactly my weakest time of the day, so I'll happily stand corrected. <div class="Discussion_UserSignature"> <p>.</p><p><font size="3">bipartisan</font>  (<span style="color:blue" class="pointer"><span class="pron"><font face="Lucida Sans Unicode" size="2">bī-pär'tĭ-zən, -sən</font></span></span>) [Adj.]  Maintaining the ability to blame republications when your stimulus plan proves to be a devastating failure.</p><p><strong><font color="#ff0000"><font color="#ff0000">IMPE</font><font color="#c0c0c0">ACH</font> <font color="#0000ff"><font color="#c0c0c0">O</font>BAMA</font>!</font></strong></p> </div>
 
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R1

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thanks so much. <br /><br />I wonder what the shorter days affected. Could the rate of aging be different?<br />Nocturnal sleep, and the time available to get food from a daytime food chain were both over<br /> 2 hours shorter each.<br /><br />Alright, well sleep well, and thanks. At least now the earth is slower, so you have plenty of<br />time to sleep today.<br /><br /><br /> <div class="Discussion_UserSignature"> </div>
 
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R1

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maybe most of life back then was herbivorous? or do we know for sure <div class="Discussion_UserSignature"> </div>
 
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willpittenger

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One more thing I thought of: The gravitational center of an overall system (including moons) is called the Barycenter. In the case of the Earth and Moon, that is far closer to the surface of the Earth that with any other planet. This causes the the Moon to literally yank the Earth around. BTW: If Pluto were still a planet, some might call it a double planet. Its barycenter is between Pluto and Charon. <div class="Discussion_UserSignature"> <hr style="margin-top:0.5em;margin-bottom:0.5em" />Will Pittenger<hr style="margin-top:0.5em;margin-bottom:0.5em" />Add this user box to your Wikipedia User Page to show your support for the SDC forums: <div style="margin-left:1em">{{User:Will Pittenger/User Boxes/Space.com Account}}</div> </div>
 
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3488

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Thats correct Adrenalynn,<br /><br />The Jurassic was right in the middle of the reign of the dinosaurs.<br /><br />IIRC, your figures are correct. I had head something similar that the Earth's rotation <br />was around 20 hours back then. <br /><br />You came up with 19 hours, 33 minutes & 36 seconds, so IMO that is pretty close.<br /><br />I've done the same, but going back to the beginning of the Triassic, as the dinosaurs <br />were just starting out.<br /><br />250,000,000 * 0.73 = 182,500,000 seconds / 60 / 60 / 24 ~= 2,112.26 days of drift over the <br />course of 250 Million years<br /><br />24-((2112.26/250000000)*365.2524*24*60)=17.78 Hours.<br /><br />Or 17 Hours, 42 minutes & 48 seconds.<br /><br />Can you double check my maths???<br /><br />Andrew Brown. <div class="Discussion_UserSignature"> <p><font color="#000080">"I suddenly noticed an anomaly to the left of Io, just off the rim of that world. It was extremely large with respect to the overall size of Io and crescent shaped. It seemed unbelievable that something that big had not been visible before".</font> <em><strong><font color="#000000">Linda Morabito </font></strong><font color="#800000">on discovering that the Jupiter moon Io was volcanically active. Friday 9th March 1979.</font></em></p><p><font size="1" color="#000080">http://www.launchphotography.com/</font><br /><br /><font size="1" color="#000080">http://anthmartian.googlepages.com/thisislandearth</font></p><p><font size="1" color="#000080">http://web.me.com/meridianijournal</font></p> </div>
 
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confuseddotcom

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Thanks all for the replies.<br /><br />So, if i have this right, the moon does stop the earth from spinning uncontrolably off its axis?? If so, does this mean the earth could not flourish with life without the moon??<br /><br />BOB.
 
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shadow735

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Without the moon to stablize the earths axis we would not have reoccuring seasons, the earth would wobble around and weather would be chaotic and its current system of heat exchange and ocean currents would be screwed, I am sure life would persist but many species would most likely become extinct.<br />has anyone seen any computer models of the resulting scenerio if the moon were to spin off into space? <div class="Discussion_UserSignature"> </div>
 
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willpittenger

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One more thing: Without tides, many organisms could not reproduce. Finally, many insects find their way around with help from the Moon. <div class="Discussion_UserSignature"> <hr style="margin-top:0.5em;margin-bottom:0.5em" />Will Pittenger<hr style="margin-top:0.5em;margin-bottom:0.5em" />Add this user box to your Wikipedia User Page to show your support for the SDC forums: <div style="margin-left:1em">{{User:Will Pittenger/User Boxes/Space.com Account}}</div> </div>
 
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MeteorWayne

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Well, that's a bit of an overstatement.<br />The seasons would reoccur, but over periods of hundreds of millions of years the "depth" of the seasons would change. For a few hundred million years winter might be longer, darker and colder, and summer longer lighter and hotter. Then for a few hundred million years after that, the seasons might almost go away. That's what Mars goes through. <div class="Discussion_UserSignature"> <p><font color="#000080"><em><font color="#000000">But the Krell forgot one thing John. Monsters. Monsters from the Id.</font></em> </font></p><p><font color="#000080">I really, really, really, really miss the "first unread post" function</font><font color="#000080"> </font></p> </div>
 
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MeteorWayne

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It seems likely that the moon's presence has made conditions more favorable for life to develop and flourish.<br /><br />Not necessary, but it's made it more comfortable for the life that formed. <div class="Discussion_UserSignature"> <p><font color="#000080"><em><font color="#000000">But the Krell forgot one thing John. Monsters. Monsters from the Id.</font></em> </font></p><p><font color="#000080">I really, really, really, really miss the "first unread post" function</font><font color="#000080"> </font></p> </div>
 
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shadow735

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The moon causes the tides and the tides hitting the coast help clense the ocean of toxins and waste, I saw something about that a while back, anyhow without the moon, the earth would most likely be severly wounded, it most probably will not die but all species will be affected, either by extiction, or forced to evolve to the new conditions to survive.<br /><br />there are so many variables that could happen to the earth, that you would make a book about them. <div class="Discussion_UserSignature"> </div>
 
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MeteorWayne

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I actually have on about the moon thing called<br />"What if the Moon Didn't Exist" c 1993 by Neil E Comins.<br />Subtitle is: "Voyages to Earths That Might Have Been"<br /><br />It provided a lot of early thought about the subject over the last decade for me. <div class="Discussion_UserSignature"> <p><font color="#000080"><em><font color="#000000">But the Krell forgot one thing John. Monsters. Monsters from the Id.</font></em> </font></p><p><font color="#000080">I really, really, really, really miss the "first unread post" function</font><font color="#000080"> </font></p> </div>
 
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usn_skwerl

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they had a show on Discovery Science a while back about the moon not existing. pretty interesting. <div class="Discussion_UserSignature"> </div>
 
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usn_skwerl

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I do believe that might have been it. <img src="/images/icons/smile.gif" /><br /><br />it talked about the earth wildly flipping about, that we had a day of about 20 hours in the day of the dinos, and that we're fortunate that we're alive now, as far as the moon is concerned, because the moon's slipping away from us, so total eclipses will be a thing of the past. <div class="Discussion_UserSignature"> </div>
 
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willpittenger

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The show I mentioned did <font color="yellow">NOT</font>include any of the following:<li>Length of the day in the time of the dinosaurs<li>Total eclipses being a thing of the past (not going to happen for at least 5-6 millenia)</li></li> <div class="Discussion_UserSignature"> <hr style="margin-top:0.5em;margin-bottom:0.5em" />Will Pittenger<hr style="margin-top:0.5em;margin-bottom:0.5em" />Add this user box to your Wikipedia User Page to show your support for the SDC forums: <div style="margin-left:1em">{{User:Will Pittenger/User Boxes/Space.com Account}}</div> </div>
 
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symbolite

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We've had this moon for way longer than since the dinosaurs, does that mean days on Earth were once really really short? Like less than 5 hours or something? <div class="Discussion_UserSignature"> </div>
 
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