Re: VERY OT--political note(please ignore if you think it's too OT)

On 7 Nov, 06:11, Nick Cramer <n_cramerS...@xxxxxxxxxxx> wrote:
"Ozgirl" <are_we_there_...@xxxxxxxxxx> wrote:
Peter C wrote:
On 5 Nov, 18:41, "Michelle C" <bookbug...@xxxxxxxxx> wrote:

I really don't see how people can funtion without knowing where
nations, cities, etc. are located. To me, that's like failing to
understand the Earth circles the sun.

The Earth doesn't circle the Sun - both the Earth and the Sun orbit
the centre of gravity of the Solar System.

Orbit is the correct word  but the earth DOES orbit the sun.

Actually, Ozgirl, Peter is quite correct. Similarly, the Moon doesn't orbit
the Earth. They both orbit the center of mass of the Earth-Moon system.

Spot on Nick. All the bodies in the Solar System orbit the centre of
gravity of the Solar System ( even the Sun ). Since the Sun accounts
for 99% of the mass of the Solar System the centre of gravity of the
Solar System is deep inside the Sun - offset from the centre of the
Sun by several hundred/thousand miles. So bodies like the Earth have
to go the long way round the centre of gravity and that gives rise to
the optical illusion or metaphorical/everyday/poetic explanation that
the Earth is orbiting the Sun.
The Sun just wobbles on its axis as it orbits the centre of gravity of
the Solar System. The wobble isn't really apparent to us but aliens
light years away might be able to detect it and could deduce from the
wobble that the Sun had a retinue of planets.Perhaps that's why the
Roswell chaps turned up :-)
The Moon is too big and too close to be regarded as a satellite of the
Earth, most astronomers now describe the Earth-Moon system as a Double
Planet.
And of course nothing "circles" the Sun - all(?) the orbits are
elliptical, including the Earth's.

.

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