# The Naked Scientists Forum

### Author Topic: anchor a big rope to the earth.....  (Read 2970 times)

#### paul.fr

• Guest
##### anchor a big rope to the earth.....
« on: 11/05/2007 01:38:22 »
What would happen if we attached a rope (assume this is possible)to a fixed point on the earth, on the other end was a, lets say 100ton weight.

we sent the weight out into orbit, would the weight spin around the earth like a hammer thrower and hammer (bad analogy) or what? why?

#### another_someone

• Guest
##### anchor a big rope to the earth.....
« Reply #1 on: 11/05/2007 01:58:53 »
Depends totally on the length of the rope, and what speed the weight starts out at.

Very easy experiment - tie one end of the rope to your floor, and another end to 100 ton rope, and raise it 10 feet up - the weight will drop - like a 100 ton weight.

If the rope is long enough to put the 100 ton weight into geostationary orbit, and you are at the equator, and weight is already orbiting at the right speed to maintain geostationary orbit, then the rope will make no difference.  If the weight is orbiting at too slow a speed, then it will drag on the rope, which will lower its altitude, and although it will then pick up speed, it will be at too low an orbit for the speed it is travelling, and so will fall to earth.

If the rope is long enough that it will let the weight out to beyond the range for geostationary orbit, then again, the weight will drag on the rope, but it will now pull it down towards a geostationary orbit, and depending on how much slack it has, it could well just pick up enough speed as it reached the right altitude for geostationary orbit.

All of this assumes you are at the equator.  At any other latitude, I would suspect most scenarios (possibly all) would simply drag the satellite down to earth.

#### paul.fr

• Guest
##### anchor a big rope to the earth.....
« Reply #2 on: 11/05/2007 02:02:22 »

Very easy experiment - tie one end of the rope to your floor, and another end to 100 ton rope, and raise it 10 feet up - the weight will drop - like a 100 ton weight.

I would do but i hurt my back yesterday. So it will not swing around?

#### lyner

• Guest
##### anchor a big rope to the earth.....
« Reply #3 on: 13/05/2007 00:30:43 »
There are some half-serious proposals for a system like this as a method for lifting objects up into low orbit. Once your tether is in place, you could operate a 'lift' system which wouldn't need rockets - which are much less efficient.
The string has to be incredibly strong and light, tho. It would be a navigation hazard for aircraft and other orbiting objects, too.

#### The Naked Scientists Forum

##### anchor a big rope to the earth.....
« Reply #3 on: 13/05/2007 00:30:43 »