/sci/ - Science & Math

is dat sum gravity op

Solar tidal forces stretched a primordial earth, and we lost a big chunk of ourselves. Also picture is greatly exaggerated to show the relative differences

The moon is on the right side of the earth in that pic. Thus its extending tward that direction. of course tho, any realistic effect of the moon is highly exaggerated in your picture

what the shit is this

>>1634686

Implying that the moon can distort the shape of the earth to any noticeable degree.

What? The moon is more uniformly smooth than a billiard ball.

>>1634704
sigh, dear god, I meant the Earth. Fuck me I'm tired

>>1634712

Exaggerated image to show where the lumpiness is.

>>1634712
no it isn't

The shape is caused by plate tectonics, with the weight made up by the weight of the ocean. If you took out the water, gravity would force the earth into something much more like a sphere.

Tidal forces of the sun have nothing to do with it. The collision that created the moon completely melted the earth, and ever since then the tidal forces from the moon have been about 10x the tidal forces from the sun. And these tidal forces don't reshape the earth significantly, except for the oceans.

The moon's gravity deforms the earth at most 12 inches.

>>1634719
The lowest point is 6.85 miles below sea level. The highest is 5.49 miles above sea level (12.34 miles relief). The Earth's diameter is 7900 miles. That's 1/640 of the diameter of the Earth. So the greatest non-global (ha ha) height change on a billiard ball must be (2.25 in /640) = 0.003515625 inch.
Is this true? lol.

>>1634867
Note that the weight of the tide counteracts much of the Moon's influence, although the torque does increase the strain between land and ocean areas.

An American sat there.

>>1634901
But remember that these deviations from sea-level are not from a SPHERICAL reference, but an OBLATE SPHEROID, which is fat around the equator, because of the earth's spin. So if you had an earth-shaped billiard ball, it would be noticeably non-spherical, especially if you try rolling it.

here, have a gravity map

It's a rock.

When have you ever seen a perfectly spherical rock?

>>1635436
To be a planet, a rock must, among other things, have enough mass to become spherical under its own weight.

>>1634672
over population in india, thats why the ground is sinking

>>1635474

It is spherical but not perfectly spherical.

this is not actually the shape of the earth its the shape of the geoid mapped into this by a satellite called goce here the differences have been exaggerated but look it up

http://en.wikipedia.org/wiki/Gravity_Field_and_Steady-State_Ocean_Circulation_Explorer

>>1635489
The Earth has less imperfections than a billiard ball, but it's an oblate spheroid because of the spinning of the Earth.

>>1635417

Bermuda Triangle and Dragon's Triangle on the opposite side of the Earth