The moon?

[andrea81]

Why do we only see one side of the moon? And why don't we ever get to see the dark side from earth?

[emeritus]

Because the moon is in Synchronous Rotation with the Earth.

The Moon makes one rotation every 29.5 days. That happens to also be the time it takes for the Moon to complete one revolution around the Earth so we only see one side.

[Loosehead]

The moon is tidally locked so as described above it takes exctly the ame time to rotate as it does to orbit. So obviously we cannot see the "Dark side", which isn't actually dark anyway.

[andrea81]

Cheers, think I get it!

[WaldoMcFroog]

There is no dark side of the moon really. Matter of fact it's all dark...

[andrea81]

Waldo -

you can't make a comment like that without explaining. I'm a converted blonde and that just confuses me!

[Loosehead]

Waldo means the moon emits no light of it's own. I was saying that the sun shines on all of the moon as it rotates so the "dark side" is not actually unlit!

[johnlambert]

How do you know what waldo means Loosehead?

[andrea81]

Yes but one bit is light and one bit is dark and it's always the same bits that are dark or light! So we never get to see the bit that is always dark!!!!!

[dundurn]

Another factor to take into account is that the moon wobbles a bit (I think the technical term is libration, but don't shoot me) as a result we do see a bit more than 50%, sometimes a peek round the RHS and later a glimpse around the LHS.

[Loosehead]

No Andrea, the same bit faces us but when the moon is new or partial, as in a crescent then a bit of what you think of the "dark Side" is in fact lit by the sun but we cannot see it. visuallise the Moon orbiting the earth and the whole lot being lit by the sun then when the sun passes between the earth and the sun then the moon is lit on the far side, a good example of this is during an eclipse.

I know what waldo means john because it's a common "trick" question, ie "how much light does the moon give off?"

I'm sure Waldo will verify in a mo!

[johnlambert]

The light is reflected from the sun Looseheid sooo in my opinion, it does give off light.
In my opinion lol

[andrea81]

Well I think the moon is made of cheese... so there!

[fo3nix]

Imagine you're stood still in a room. You're the Earth.

Now get someone else to stand a few feet away from you, facing you. Get them to walk round you, while always facing you.

Because they're always facing you as they walk round you (more in a crab-like way, perhaps), their dark side is their back. The same goes for the Moon.

If you notice though, as they walk round you, they do rotate once as they have rotated around you. This can be easily seen if they hold a stick out in front of them, perpendicular from the middle of their chest. Because they're always facing you, the stick will always be pointing to you. But if you look at the stick as a bird would from above, you'll see that as they walk completely once around you, the stick rotates too (because they do).

Make sense?

[andrea81]

Oh my gosh, my head hurts! Well I think I can imagine that i'm turnign just as the moon goes around us, but I just just find it fascanating how the moon turning and us turnign woudn't result in being a bit off timing so we start seeing the dark side at some pint!

[WaldoMcFroog]

Zacsmaster is correct - it's the final soundbite at the end of 'Elcipse' on 'Dark Side of the Moon' by Pink Floyd. I know it was facetious, but it seemed apposite!

Since it's such as classic, I thought more people would know it.

[Loosehead]

It's Tidally locked, the tidalforces of both bodies pull them to each other, no deviation is possible unless there is gargantguan force of some sort, it's like an adult swinging a small child around, the child and adult balance each other so that neither can deviate, the centre of gravity adjusts according to the relative mass, so in effect the adult actually wobbles a little too, but they still face each other.

[andrea81]

Pink Floyd - what do you mean about that - my hubby loves them and I just don't get what relevence there is about my question. Please explain so I don't feel stupid ; - )

[Loosehead]

There's a Floyd Album called "Dark side of the Moon"

[Reverandfunk]

But have we really been to the moon??........