GeologyRocks

Off the top of my head, I'd say that the presence of the Moon influences the tides on the earth, but not much else. Without the Moon, the tides would still be there (because of the gravitational attaction to the sun) but would be a smaller tidal range.

I understand that the formation of the Moon is thought to be due to a large meteor colliding with the Earth early on in planetary development. I think this collision occurred when the Earth was beginning to cool (i.e., before development of life). The results of collision would be axial tilt (causing seasons), etc. (and I think a possibility of crustal differentiation that may have helped plate techtonic).

As for the formation of life, I think that life would have got started and evolved regardless of whether we had a moon or not. Life may not have looked the same without the axial tilt or higher tidal ranges, but it would have still started and evolved. I don't see any reason why this evolution would not eventually produced lifeforms that had a "human"-type intelligence.

That's just my 2 cents (I can believe that the computer folks have gotten rid of the cents symbol from the ASCII code).

Thanks
Canadarocks

Without the moon, life at night on earth would be awful, from a creative point of view. I'm often inspired to write something, whilst sitting under a moonlight night, but if there was no moon, would magnetic fields on earth be affected?

I dont think that the Earths magnetic field would be affected. The moon possibly has a very small magnetic field, but it is nothing in comparison to the Earths.

The Moon has vitually no magnatic field now but did have a field of about 2000nT 3-4 billion years ago (from palaeomagnetic evidence) before its core solidified. This, however, is still peanuts compared with the Earth's 30000-60000nT present day field.

If, however, the theory if a giant impact from the origin for the moon is correct then the impactor's core would be incorporated into the Earth's. The larger core might then have implications for a stronger Earth's magnetic field than would otherwise have been the case (or indeed a completely different style of mantle convection and type of magnetic field). This would possibly influence evolution as the effect of cosmic radiation at ground level might have been greater (but to what extent would be debatable).

p.s. the first paragraph is based on accepted science, the second on a bottle of cabernet sauvignon!

The moon has a stabilising effect on the angle of obliquity of the Earths axis of rotation which helps it remain stable at around 23 degrees. Without it the effects of the Sun's and Jupiters gravity would have cause this angle to vary significantly more than it has. This is demonstated in Venuses obliquity where the planet it thought to have flipped through 177 degrees.
This would have a large impact on the evolution of life but as far as the development of intellegent life is concerned I don't know. Maybe the climate would change to fast for it to evolve or maybe greater intellegence would be required to adapt to it.

The moon also has an indirect effect on the weather but this is mainly due to the tides causing ocean currents to move large volumes of water which influence the atmospheric conditions, but this is only an indirect effect.

if there was no moon, would the speed at which the earth rotates speed up or slow down?

I don't think so. IIRC, the speed of earth's rotation was set when it was formed. I'd think that if the moon's gravity was enough to decelerate the earth's orbit, the two would be in synch by now, and I haven't read anything that has said the rotation has slowed down.

and earth's magnetic field is created by the liquid outer core rotating around the solid, stationary inner core, sort of like a generator. So I don't think the abscence of the moon would affect that either.

how it would have affected life......I'm not sure. certain organisms use the tides in different ways, so their evolution would have been different (or they wouldn't have existed at all). Others use moon light for various things (seeing mainly, I would think, and perhaps something with the phases). and as theape said, it helps stabilize the earth, so the seasons aren't wildly different. so it would be hard to say.

Directly the moon has no effect on the angular velocity of the planet because the only way of slowing it down is by doing work on it and the deinition of work is
Work done = Force X distance moved in the direction of that force
(Isn't A level physics brilliant)
And gravity, the force the moon excerts on the Earth is perpendicular to its rotation so no work can be done.

HOWEVER

The Earth is slowing down very very very slowly as an indirect cause of the moon. This is because the tides, caused mainly by the moon, make large volumes of ocean water to bulge (high tides) on the side of the earth facing towards and away from the moon. Because the orbit of the moon and rotation of the Earth are out of sync the Earth is rotating at a different rate to the bulges of water (tides) so work has to be done to overcome this difference and this work comes from the angular velocity of the Earth.

But don't worry, this slowdown is only about 0.005 seconds per year

Hope everyone understands, if not let me know and I will try and explain it better, or if its a hard question I will run away.

My argument about the core was that in the formation of the Moon the size of the Earth's core increased substantially due to gaining most of a Mars sized body's core. The larger core would convect in a different way to a smaller one with out this happening and therefore the Earth's magnetic field is/has been different to that if there wasn't a Moon.

I concur with James, Devonian corals have growth rings suggesting ~400 days per year showing the slowing in the rotation rate of the Earth

I was reading that the Moon was moving away from the Earth, so in a billion or so years the moon will be so far away that eclipses do not occur.
Its apparently moving away at a rate of 3.82cm per year. Not much, but it is over geological times: Continental drift is about the same.
The value varies according to how much water is in liquid state (physics things explain why). So all you have to do is wait in cryo-storage or something, and then see for your self how it affects life!

When the moon was closer to the planet its gravitational attraction used to raise the surface of the planet by several hundred metres, this would have triggered greater geological actrivity than we have today, such as earthquakes. I do not know the effect this would have on the evolution of life though.

I would have thought that because the moon was closer in the distant past, it did have an effect on evolution, and that path has so far lead to us.
Doesn't say alot for evolution though does it!

Amoon could of split from the earth from an earthquake ? like the biggest ever earthquake.

Dont think so, because the energy needed to push a lump of earth spaceward would have to be stored in the earth, and then released. I haven't heard of lumps of rock being pushed into the sky in an earthquake (not that that means anything ). that is why NASA and space program peoples dont use a massive spring board to push things into space, they have to use good old water making elements (and some not so good chemicals!) to push a rocket skyward!

Good point. The amount of energy that would have to be released from the earth to do this would would have huge ramifications on the orbit of the planet and would probably have resulted in the earth shaking itself to pieces anyway. Also Ape you should now better than to say that evolution has led to us, that suggests a higher purpose rather than a random event. What about all the other species that evoluition has produced up to now, has evolution not led to them as well? It is a bush not a tree!!

I know I said "and that path has so far lead to us.", I was meaning that our ancestry has lead to us. I did not mean that a squirrelÂ’s ancestry has lead to us, no matter how many similarities you see in some people! So I apologise for the misunderstanding that I may have caused. :oops:

Carry on as you are (theape) and you will soon be a Fundamentalist evangelical christian.

God bless you my son. And intelligent design is a scientific principle. And... and ... and... Scientist's doesnÂ’t know anything, and God is everywhere, but every one will go to hell, oh! That contradicts!

Pax Vorbiscum my Children.

I have googled this and cannot find what it means, pax means a period of peace and stability but do not know if it applies here.

It means 'Peace be with you', as in I was just trying to calm your's and the Ape's little spat! Reminds me of when you two were together in class. Although I still have Ape there now! He has a new sparring partner in the form of kelvin though he is not quite the same as you with regards his proficiency in personal comments!! I also thought it would be a nicely ironic religious phrase to use as you two seemed to be getting all theological.

Its a bit more difficult to "spar" with Kelvin. He doesn't own a camplion car, he is quite good at maths, and he doesn't often dig himself into a hole, unlike someone we know!

I was planning to fit in with the miners in the Camborne School of mines here, they like holes in the ground. Unfortunately the renewable energy concensus is that they are some kind of alien race in a parrallel dimesion to that of earth. They live in a miners world that you can only understand if you are one of them.

Will not say more as it is possible thay may read this and I have to live inthe same flat as one of them.

I wouldn't get too sniffy with your Dwarf (re LOTRs) friends as you still need them to extract all that raw material to build all those wonderful new renewable plants in the future. Funny, when you look at it like that renewable energy may not be so clean after all, and the Dwarfs might have got it right!!

The miner who lives in my flat has invited his miner friends around and for a joke they have broken through a door which leads to the toilet cistern in my room and have poured washing up liquid in it so it will froth up next time I flush the toilet. They are very noisy though so I heard them.
They have had peeing contests through the 'second floor' kitchen window before aswell.
They have not gained there campus wide reputaion for no reason.

I heard the same thing. Supposively the moon used to look 15X the size it does now in the sky...that would have been cool to see.

I saw a show on the Science Channel a few weeks ago about this. They said that without the moon, the Earth would slow down significantly, and then it would spin in all different directions randomly( I.E, snowstorms in Africa, and desert in Antartica, etc.)

I thought that the moon was slowing us down anyway? but it is supposed to keep us more stable than a planet without a moon.
In the guiness book of records it says that the longest day ever in history is today, as it is very slightly longer than yesterday.
cant find link on their web page though. :x