The Pole/Gravity Curvature!

[liber_scientia]

I know, I know. No such thing exists. It's a question.

I have to give credit to my friend who put forth this idea, and I'm losing my mind trying to prove him wrong.

--

Say we placed a giant iron pole on the Earth. Pretend it was big enough to match the scale shown in the picture.

 

http://img386.imageshack.us/my.php?image=mindnumbingcurvaturend2.jpg

 

What would happen to the pole?

 

The gray lines in the pictures represent the pull of gravity. So, I believe that the pole would be bent to match the curvature of the earth.

 

Now imagine that the same iron pole was placed miles above the Earth, and that the pole was longer than the circumference of the Earth.

 

If the distance from the center of the Earth to the pole created a radius for a circle with a circumference equal to the length of the pole, then the pole would likely create a ring around the Earth.

 

BUUTT!!111!1oneoneone!112

1. The Earth is not a perfect sphere.

2. Earth's gravity is not perfectly uniform.

 

This means that the pole, if distanced from the Earth, would not create a perfect ring.

However, I theorize that it would warp to match the gravitational field of the Earth. If observed carefully, this would effectively map the gravitational field of the Earth.

 

 

Tangent: Complete

[Klaynos]

I doubt the pull of gravity would be strong enough to overcome the strength of a metal poll that much. But I fail to see how, it'd stay in a stable position for long enough to curve or why it would curve to create a ring instead of just a horseshoe shape or something similar...

[D H]

If the pole were made of some unstretchable, incompressible, unbreakable, and unbendable material (unobtanium in short), the Earth would undergo significant harm, but nothing much of interest would happens to this pole. Suppose, on the other hand, the pole is a thin, malleable wire. This, I think, is closer to what the OP is referring than the rigid unobtanium rod.

 

What is going to make the wire wrap itself around the Earth? There are a lot of different cases to study here. I'll pick a few. Suppose the wire pops into existence as a perfectly straight wire

• with a north-south orientation, justing touching the Earth at the equator, and zero inertial velocity with respect to the center of the Earth. Ignoring atmospheric effects, the wire will quickly hit a snag on the Earth (Mount Chimborazo, for instance). The middle of the wire will now be moving at 1674 km/hr. That will put a lot of tension on the wire. Even if the wire doesn't break, it certainly won't form a great circle. The wire start forming a horseshoe shape curving off to the west from the contact point.
  
• with a north-south orientation, justing touching the Earth at the equator, and an inertial velocity 1674 km/hr due east (at the contact point). with respect to the center of the Earth. A point on the wire away from the contact point will be moving faster than the corresponding point on the Earth directly underneath the point in question. The wire start forming a horseshoe shape curving off to the east from the contact point.
  
• with an east-west orientation, justing touching the Earth at the equator. Again the velocity of the wire will effect the outcome. If the wire has zero inertial velocity, it will double up on itself once it hits a snag. There will be some doubling-up even if the wire is moving 1674 km/hr due east.

 

The wire above the earth is a bit more interesting. A rhetorical question: What is going to make the wire wrap itself into a circle, as opposed to simply falling to the Earth? Answer: Nothing.

 

Suppose instead of an initially straight wire we have a very large spool of wire in a circular orbit around the Earth. We'll connect one end of the wire to a vehicle with thrusters. We'll use some kind of forced motion to make this vehicle move a tiny bit faster (or slower) than orbital velocity (but stay along the orbital path) and unspool the wire. Eventually our vehicle will rejoin the spool. At this point in time, we'll splice the free end of the wire to the wire coming out of the spool. Voila! We have a wire circling the Earth! The wire won't come crashing to Earth -- immediately, that is. The ring is unstable. See http://eprints.gla.ac.uk/38/01/JIBS_C_McInnes_56_308.pdf for example.