How things would be different on Earth without the Moon
Bernard Foing wrote an article for Astrobiology Magazine about how our Earth, its weather, and its life forms would be different without the influence of the Moon.
Link (Via Daily Grail)The eyesight of many mammals is sensitive to moonlight. The level of adaptation of night vision would be very different without the Moon. Many of these species have evolved in such a way that their night vision could work in even partial lunar illumination, because that’s when they are most active. But they can be more subjected to predators, too, so there is a balance between your ability to see and your ability not to be seen. The Moon has completely changed evolution in that aspect.
Human vision is so sensitive that we are almost able to work by the light of the Milky Way. The full Moon has more light than we need to see at night. For most of our history, we were hunting and fishing or doing agriculture, and we organized our lives by using the Moon. It determined the time for hunting, or the time where we could harvest. That’s why most of our calendars are based on the Moon.
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I'm surprised to see no mention of tidepools, and all the plants and animals adapted to living half the day in the water, and half out of it. Without significant tides, it would seem that the transition to land would be a lot trickier: certainly streams can dry up, but the transition from wet to dry is over a much longer time period.
The world would have a lot less shellfish.
I was always impressed with the improbability that the apparent diameter of our moon is so close to that of our sun. I don't recall precisely which experiments and conclusions they were, but at least one major observation in the history of astronomy was dependent on this coincidence. If nothing else, the realization that such apparently similar sized objects were at considerably different distances was a major development.
Also, to emphasize the last few statements of the linked article, I understand that Aristotle attributed his belief in the roundness of the Earth to the observation of the shadow of the Earth during Lunar Eclipses (although since reading that I've keenly observed such phenonema and have been perplexed at how he could have made out such a distinct curvature of the very fuzzy shadow I always make out).
Galileo's observation of the moon through his telescope was also very key, from a cosmological perspective. He wrote about seeing the imperfections (the rough craters) on a previously thought pearly smooth surface, thus calling into question that everything in the Celestial Sphere was Perfect.
I was always impressed with the improbability that the apparent diameter of our moon is so close to that of our sun. I don't recall precisely which experiments and conclusions they were, but at least one major observation in the history of astronomy was dependent on this coincidence. If nothing else, the realization that such apparently similar sized objects were at considerably different distances was a major development.
Also, to emphasize the last few statements of the linked article, I understand that Aristotle attributed his belief in the roundness of the Earth to the observation of the shadow of the Earth during Lunar Eclipses (although since reading that I've keenly observed such phenonema and have been perplexed at how he could have made out such a distinct curvature of the very fuzzy shadow I always make out).
Galileo's observation of the moon through his telescope was also very key, from a cosmological perspective. He wrote about seeing the imperfections (the rough craters) on a previously thought pearly smooth surface, thus calling into question that everything in the Celestial Sphere was Perfect.
The band I'm in, Half Acre Day, just released a record that has a song on it about this very thing. With all the talk of advertising on the Moon and mining the Moon, my friend wrote a song about it exploding - being from Seattle a line goes "I tried to see it, but the clouds got in the way."
The fact that we are mostly made of water and the moon's pull on liquid is obvious, it's no wonder we are affected by and biologically bound by the moon.
Sure would miss it if we screw it up.
hcvotz: The diameter of the moon and sun differ by a factor of over four hundred! The diameter of the moon is 3,474 kilometers. The diameter of the sun is 1,400,000 kilometers. However, because of their relative differences in distance to us, they appear roughly the same size.
I wonder how the rotation of the moon, such that the same surface always directed at the earth, affected early astronomy. If the moon had a different rotation, they could see it spinning. Then wouldn't early observers have been able to guess that the earth is also round and spinning at a much earlier point in history?
Funny how folks miss that the moon is our shield from some nasty stuff. I think the moon is also why the Earth's core is more stable than Mar's is.
In college I took a course with Neil F. Comins, who wrote "What If the Moon Didn't Exist?", which posited numerous circumstances in which we'd not be able to survive were the moon and our relationship to it altered.
- Chris
Raffy,
The APPARENT diameter means how the disc appears to the human eye from Earth.
But good point about the interesting fact that we see the same side of the moon all the time. That was another fact that intrigued me, insofar that it did probably set some discovery back.
Here's a very entertaining book-ful of such intersting conjectures, not least amongst which is "What if Earth was tilted like Uranus?"
What If the Moon Didn't Exist?
by Neil F. Comins
Harper Collins 1993
ISBN 0-06-016864-1
And for folkie Christine Lavin's take on this issue: http://www.youtube.com/watch?v=YyOyH9u4AdI
There was a great special on the SCIENCE channel (part of Discovery Channels) called IF WE HAD NO MOON (now out on DVD).
The eyes thing is the least our worries - apparently no tides and worse, Earth would violently wobble and spin as we rotated so we would move from pole to equator to another pole, etc ...
The moon is receeding about 2" away from us every year and in about 250,000 years (or so), it would drift so far away, we'd need a replacement moon ...
http://shopping.discovery.com/product-52214.html
Joe, they do mention tide pools.
It's not really an improbability that the moon has the same apparent diameter as the sun but a coincidence that we are alive when it is the same. We just happen to be here to see it as it is as it's orbit gradually expands. Plus the moon's orbit isn't circular so at some points it's further away which results in an annular eclipse (saw one of those at sunset in the 90's, was very cool)
One thing I read said the we won't eventually lose the moon. One day billions of years from now the moon will reach geostationary orbit and will reside over one spot on the earth (the earth will always show the same face to the moon)
i read once that the moon might be responsible for ALL life on earth...the reasoning being that in order for molecules to interact in such a way that proteins form (and then simple life to arise from these) requires a certain number (a very large number) of random molecular interactions. without the moon churning the oceans, this number would be seriously reduced. of course thats if you dont believe in the possiblity of panspermia.
hcovitz, the observation you're thinking of (based on the identical apparent diameter of the moon and sun) is the proof of einstein's relativity, which is generally agreed to be the most dramatic proof in the entire history of science. relativity predicts that matter causes space to curve, generating the force we know as gravity, and that this curvature of space by massive objects (such as the sun) would be observable as a lensing effect, causing objects (such as distant stars) along a line of sight near that massive object to be visibly distorted and moved from their normal positions. when the moon eclipses the sun, it becomes possible to observe stars very close to the suns limb that would otherwise be lost in its glare, and indeed observations during the eclipse of 1919 proved this to be true and stars near the sun were found not to be in their normal spots. (as far as distortion goes, stars are so small compared their distance that their angular diameter is effectively zero, even with the largest telescopes, so they have no shape to distort (there are exceptions however, mainly a small handful of huge red giant stars relatively nearby), but numerous galaxies have been spotted with extreme distortions caused by foreground galaxies, some so extreme that these galaxies appear multiple times in the sky around the forground object...neat, huh?)
I enjoyed this book on the current hypotheses of the formation of the moon.
http://www.danamackenzie.com/books.htm
It also mentions effects of the moon on us humans.
--Kerry
I wonder how different it would be on the moon if humans didn't exist?
I know "The Honeymooners" wouldn't be quite the same...
JBelkin #12: "The Earth would violently wobble and spin as we rotated so we would move from pole to equator to another pole, etc"
Right, so the moon is responsible for stabilizing climate, i.e. for ensuring that the cold places stay cold and the warm places stay warm.
I wonder how fast that would change without the moon. I mean, without the moon, how long would it take for the axis of the earth to move from a currently-polar area to a currently-equatorial area? If it takes millions of years, then such climate change is slow enough for life to migrate and evolve to keep up (there are other climate change forces that act even faster). But if it takes thousands of years, then it could indeed have scrubbed the world clean of life pretty fast. If nothing else it would freeze or dry up any primordial life before it had a chance to swim/crawl away!