'Rising tide'

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So, can anyone here explain (in all seriousness), what the direct consequence(s) of there being no moon in our orbit would be. Or maybe even just a link directing me to an article on such a thing.

I ask here because it may be simple enough to explain, if the knowledge were already that common, and could be brought to my attention w/out extensive reading hopefully (not that I would mind reading up on it if that be the case).

Without our rather large moon (it is really another planet) the wobble of the earth around its axis of rotation would be chaotic. This would produce tectonic and climatic effects which would have made the evolution of our species well nigh impossible. We exist as we are because we have our moon to keep the wobbles under control.

ruveyn

depends on how you look at it.

If it suddenly disappeared, yeah, there would be @#$ to pay...

If it was never there, our day would be different, there'd be no tides, and a lot of moon goddesses would be out of work...

Our first landings would have to be on Mars. Heaven knows how fertility cycles would be changed..

I think someone has written a book about what the earth would be like with no moon...if I only could remember the name of it.

I see. Praise the moon!

I guess, lol.

If there were no moon there would be no us.

ruveyn

Say, just for discussions sake, that there could be humanity without the moon. As well as these other changes, agricultural development would have slowed to a halt without the moon to lengthen the day with extra, though pale, light. Furthermore, it is a manner of counting months, which makes crop rotation possible. Also, without a moon in the sky, astronavigation for early sea-going vessels would have been seriously more complicated.

No moon = no difference.

That's assuming no one can point me at a moonless world in a similar orbit to ours, around a similar star, where life similar to ours has NOT evolved.

Well, you can't say that. The loss of tides would certainly have some profound ecological impacts.

Presumably life on such a planet would be shocking different if it could exist, theoretically.

Well... I can say that, as I did.

Other than the obvious direct differences (like no LUNAR tides), you need to show exactly why this planet is substantively different from the other inner planets, say.

I always find it tiresome when people argue from an utterly anthropocentric viewpoint.

We have some simulations for what might happen under different conditions, but here, we have so few practical cases (just the eight planets, basically). People then extrapolate what can or can't be the case elsewhere, based on such a meagre sample.

If anything, the "scientific" view has become more blinkered recently, with an obsession that oxygen dihydride is essential to life.

It doesn't however mean you are correct.
The original poster asked what difference it would make, not what difference it would make on life.
If the moon were to be removed from it's orbit around the earth, changes would happen on earth.


As far as i am aware scientists do not believe water is essential to life. But looking at the universe it is generally believed that the conditions for other substances being used as the main medium for life are hard to reach naturally (they would require many unlikely time-dependant events happening in concurrently and in sequence.) Given the scope of the universe it would be wise to assume that there are life-forms that are not based on water. But if we (using scientific method and probability theory) decide that 99% of lifeforms will be based on water, then we must put 99% of our thinking into lifeforms based on water. It would be illogical to do differently.

This is a water planet ( a rare thing in the solar system). We have a water world because earth is in a temperature zone which permits water to exist in three physical states; solid, liquid and gaseous. Without a moon and liquid water being sloshed about by the solar tides the earth would wobble in a chaotic manner about its axis without the moon to steady it. Angular momentum is conserved in the earth-moon system so that some of the wobbles are taken up by the moon which nutates.

Life as it evolved would have been very different if the climatic conditions produced by chaotic wobbles had prevailed.

We exist as we are, because the moon exists as it is.

ruveyn

In actuality? who knows, no one on this planet.

In theory? The safer bet is to say we wouldnt exist as we do. Humans can adapt, we know we've evolved through ice ages. And other variances in climate conditions. But the minimal wobble of earth on it's axis due to the moon still has kept the climate changes relatively predictable and on a pattern. Without it I think it's safe to assume those patterns would be much larger and a lot less predictable. How much of life as we know it could have evolved through drastic climate changes every few thousands to 10s of thousands of years as opposed to hundreds of thousands to millions of years? And not gradual falls in temperature of a few degrees, but 30 degree differences over short periods?
And our moon sits comfortably far away right now, but all evidence leads to its formation just outside the roche radius, some 20k miles away, not the 230-250k it is now. So it's influence was drastically larger and had a much larger effect on the planet and its development.
Not to mention how much of a catalyst agriculture was to the development of the modern society, and agriculture just doesnt exist without the seasons (though realistically, we're talking totalitarian agriculture which did develop over a very very short period and probably too short to be effected by the rapid climate changes that would be caused with an extreme wobble)

A better question is, since the moon is slowly moving farther away, what will we do when it does no longer have a significant role? Will we, or are we, advanced enough to deal with the consequence. Thought that's a silly question cause it is trumpted by an even better one, who cares? since we probably wont be around that long =P

Water is essential to our kind of life. We are 70 percent water. Without water the kind of life we have on earth, base on RNA and DNA would not exist.

ruveyn

I'd quite like a pointer to somewhere that tells about this "the moon makes us wobble LESS" idea.

With the three body case (Sol/Earth/Moon), we have quite rapid (astronomically speaking) chaotic changes of orbits, etc.

In a simpler two body case (Sol/Jupiter), there is little chaotic going on - they essentially just follow elliptic orbits about their centre of mass.

Do you mind if I chip in? Ruveyn, I'm not sure that planetary formation is taken into account in your argument. Angular momentum would of been conserved in the accretion discs that would of collected to become proto-planets in the early solar system and the current prevalent theory regarding the formation of the moon (supported by the composition of the moon rocks brought back to earth) is that an impact another object with the proto-Earth early on, had ejected enough material into orbit to form the Moon. Also we really don't yet know how common it is to find Earth planets in the habital-zones in other solar systems. On that one I was initially going to cite Gliese 581c as a possible example but I didn't know that later research suggested that isn't case:

http://fr.arxiv.org/abs/0705.3758

Last edited by Jono on 18 Jun 2009, 3:46 pm, edited 1 time in total.