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The moon's tidal lock affected the growth of science


People who speculate about the growth of cultures have wondered if our moon (which is unusually large compared to the host planet, at least based on the limited set of planets we can see) played a big role in our societies. Did it make us more aware of the sky than people who evolved on a moonless world would be, or a world with a small moon? Did the tides have an unusual affect on us beyond ordinary solar tides?

One thought did occur to me recently. The moon's rotation period is tidally locked, meaning the moon rotates at the same period with which it revolves around the Earth, and so it always presents the same face to the Earth. From our viewpoint, it does not appear to rotate at all.

Because of that, and because it's big enough to see with the naked eye, the features of the moon were fixed and visible to all generations of humans. We created the concept of "the man in the moon."

If the moon did have a visible rotation (ie. it was not tidally locked) it would be obvious to us. It would be obvious, in particular, that it is a sphere, and not a disk pinned to the sky as it appears to be.

So ancient astronomers would have seen the moon was a sphere and probably would have figured out much earlier that the sun, the other planets, and most importantly of all, the Earth itself, were a sphere. Perhaps more importantly, it would even be obvious to the common person. And what might that have done for the evolution of our technology and society?


It can be (and was) deduced from the earth's shadow on the moon that the earth was round, likewise the moon. Try this little experiment with a lightbulb, a basketball, and a volleyball. Rotate the volleyball around the basketball and make note of the waxing/waning of the basketball's shadow on the volleyball. Now replace the volleyball with a paper plate. Notice anything different about the shadow?

I believe that the flat earth theory was just a passing phase of human culture during the 15th century. Most people (especially mariners) knew the earth was round...just look at the horizon over the's curved.

You posit an interesting question, but not one from which the growth in science can be deduced either way. In addition to the phenomena of eclipses mentioned above, the moon has a small amount of wiggle called Libration (see that is sufficient to reveal that the moon is not a simple disc pinned to the sky. I conjecture that science equally well could have been stimulated by knowledge that the moon is locked, but not COMPLETELY locked. What's up with that? In other words, the question can be posed both ways. In the final analysis, I would allow that the presence of the moon is indeed highly important, in many ways, to development of both human intelligence and imagination, but more -- that the presence of the moon has been absolutely essential to stabilizing earth's tilt, making highly evolved life possible on earth in the first place. No moon, no one to wonder what a moon could have done.

you are a very funny person!

Its only influence was curiousity and a source of idolatry

Yes, the first comment is correct, everyone knew the earth was a sphere and the renaissance people did tend to paint a bad picture of those from the middle ages.

Another easy way the Ancients could have used to know the Earth was round is that the Sun rises later as you move west. If the Earth was flat, the Sun would rise at the same time everywhere.

or had many clues. But ordinary people did not travel distances like that, or have clocks that would tell them the sun was rising later. Ancient Greeks and Egyptians even measured the diameter of the earth.

However, a spinning ball in the sky would have kept the ordinary people very aware of the concept of a sphere.

there is no such thing as man walking on the moon! nice cut and paste job and nice wind blowing on the moon. NO WIND ON THE MOON!

just thought that i would inform you about a question that has been on my mind for a long time. what would you do if someone you knew fell off a chair, went to the wrong train station and dropped their ice-cream on the tram all in the one day? these people need help just like man on the moon!

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