Gravity.

[EFLImpudence]

Not to get too technical -

Everything spins.
That's just how it works.

 

[JBR]

Not to get too technical -

Everything spins.
That's just how it works.

Even water (and everything else) going down the toilet.

 

[conny]

And my head after 4 very large Bacardi & Cokes.

 

[Dextraneous]

The reason for spinning is as simple as you being "pushed" by an HGV while on a motorway, extrapolated.

 

[sooey]

"Anyway, the bottom line is that stars like the Sun spin from the original angular momentum that was there in the solar nebula from which it formed. Not only that, all orbital motion of the planets (including the spin) is due to this orginal angular momentum."

My next question would be why was there a spin in the original solar nebula?

Nothing in space is static. The nebulae will have had a very slow rotation, but as it has collapsed to form the sun and planets this has sped up exactly like a spinning ice skater does as they pull their arms and legs in close.

 

[Mikefromlondon]

i bet the earth is not rotating of its own, but the moon going around it is pulling it about! hence moon takes exactly the same time as one rotation of the earth! thats why we see the same side of the moon and nevr its dark side.

 

[jeds]

It's around the other way. The Moon originally rotated much faster than it now does but the gravity of the Earth slowed it down until it's rotation now exactly matches Earth's rotation.

 

[EFLImpudence]

It doesn't match the earth's rotation.

It matches its own orbit.

 

[Mikefromlondon]

It doesn't match the earth's rotation.

It matches its own orbit.

You could well be right mate, or we wouldn't get moon phases if it followed a certain point on earth and the earth spun in synchronous, there wouldn't be high and low tides either.

 

[ellal]

What if the sun is on a celestial conveyor belt?

 

[JBR]

It doesn't match the earth's rotation.

It matches its own orbit.

That's right. The moon takes about 28 days to orbit the earth, and that's why a complete sequence of phases takes that long.

Incidentally, it may be just a coincidence, but I have a sneaking feeling that menstruation must be influenced by the moon's phases. My first wife comes on every last quarter!

 

[sooey]

What if the sun is on a celestial conveyor belt?

It is...kind of. It goes around the galactic centre at about 500,000 miles an hour and takes about 230 million years for one orbit dragging us along with it.

 

[JBR]

What if the sun is on a celestial conveyor belt?

It is...kind of. It goes around the galactic centre at about 500,000 miles an hour and takes about 230 million years for one orbit dragging us along with it.

I can't wait for it to come round again.

 

[Micilin]

It doesn't match the earth's rotation.

It matches its own orbit.

That's right. The moon takes about 28 days to orbit the earth, and that's why a complete sequence of phases takes that long.

Incidentally, it may be just a coincidence, but I have a sneaking feeling that menstruation must be influenced by the moon's phases. My first wife comes on every last quarter!

That's why it is called 'menstrual' . Same root as 'moon' and 'month'.

Average 28 days, same as moon's lunar cycle

'Lunar' and 'lunatic' have the same root.

Any further connections are at your own risk .

 

[JBR]

It doesn't match the earth's rotation.

It matches its own orbit.

That's right. The moon takes about 28 days to orbit the earth, and that's why a complete sequence of phases takes that long.

Incidentally, it may be just a coincidence, but I have a sneaking feeling that menstruation must be influenced by the moon's phases. My first wife comes on every last quarter!

That's why it is called 'menstrual' . Same root as 'moon' and 'month'.

Average 28 days, same as moon's lunar cycle

'Lunar' and 'lunatic' have the same root.

Any further connections are at your own risk .

Ah, so if the moon flew away she'd stop having periods? That would be nice.