All ukrm-ers are now US criminals - official

'In the atmosphere, the risk factors of wind and lightning come into
play. The basic mitigation is location. As long as the tether's anchor
remains within two degrees of the equator, it will remain in the quiet
zone between the Earth's Hadley cells, where there is relatively little
violent weather. Remaining storms could be avoided by moving a floating
anchor platform'

D.
--
des
French Biking Vocabulary: http://minilien.fr/a0kg0p

'Kaiser: "Can you prove to me the existence of G-d?"
Bismarck: "The Jews, your Majesty. The Jews"'

 

Unfortunately, based on that premise we'd all be standing at an angle
of 40-odd degrees from the vertical. It kinda forgets about the
effects of gravity, which are clearly much more significant that the
centripedal effect, otherwise we'd all just fly off into space.


--
_______
..'_/_|_\_'. Ace (b.rogers at ifrance.com)
\`\ | /`/ DS#8 BOTAFOT#3 SbS#2 UKRMMA#13 DFV#8 SKA#2 IBB#10
`\\ | //'
`\|/`
`

 

Yes, it'd whirl around the axis of rotation. How's that different to one
at the equator whirling around at a much further point from the axis of
rotation?

 

Upwards?


I knew the answer would be bleeding obvious, but the more I thought about
it, the further away I got.

 

a space elevator would have a large counterweight out beyond
geostationary orbit, so the centripetal effect is more significant
than for a relatively light person standing at ground level.

I can't believe everyone's being so thick today.

I can't believe I've just typed the above sentence.

 

Anywhere else it won't stay up.

 

they point downwards, of course. they've got weights on them.

that is, until the string gets wound all the way around the sphere.

 

heh - yes, good point; bad analogy from me in the first place.

 

One could have hours of fun dropping peas out the skylight to see if you
can score a satellite.

 

where's Simian when we need someone to do the maths?

The thing to bear in mind, is that this is not simply a very tall
building that goes into space.

It is effectively a taught cable, which is kept in tension by the
centripetal force of the counterweight out beyond geostationary orbit
level.

By definition, this force is always perpendicular to the plane of the
rotation of the Earth.

Only at the equator is this force acting in the same direction as you
want the cable to go (i.e. straight up).

Does that help?

 

Orbital speed. An object over the pole doesn't have any and so would
need *lots* of boosting to stay in orbit. An object over the equator
(if it's geostationary) has high orbital speed and this counteracts the
effects of gravity.

Phil

 

shouldn't have put "the plane of" bit, as it could have been
misleading, but happy to help.

 

Orbital speed (conservation of momentum wants to keep the station in a
straight line and because it's at the equator means you have no
sideways vector to worry about). Because it's in the right orbit the
tendancy to be flung outwards is balanced (more or less) by the pull of
the Earths gravity.

Small amounts of fuel are needed to keep the station in the right spot
(to counteract microgravity pulls from the Moon, passing spacecraft and
instabilities in the earth orbit) rather than huge amounts being needed
to fight earths gravity.

Phil

 

It has to have two anchorpoints, one on earth and one in space. The
anchorpoint in space has to be stationary in relation to the
anchorpoint on the ground, and the only possibility then is something
in geostationary orbit. All objects in a geostationary orbit will have
to be over the equator. To make the shortest route between the two
anchorpoints you put the groundanchor on the equator. This has the
added benefit that you only have to overcome angular momentum in two
dimensions and not in three.(if you discount atmospheric deviations)

 

Actually, as the earth isn't properly spherical, the equator is
further from the centre of the earth than any other part of the
planetary surface, thus giving a shorter distance to geostationary
orbit (in addition to, not instead of, wot has been said about
perpendiculars and things)

 

That's a point. Probably have to shoulder Murdoch's finest out of the
way. I unrecall if Clarke's elevator was built on an equatorial mountain
for a bit of a head start, as it were, but it would need to be, really.
--
Dave
GS850x2 XS650 SE6a

"A scone and tea at half past three
Makes the day a little brighter
Keep your cakes and fancy tarts
And stick them up your shiter."

 

Because it's 100,000 km tall, and designed to be supported by tension, not
compression. The tension is provided by rotation around the Earth's axis:
if it was sticking straight up at the Pole, it would be rotating around its
own axis and supporting its own weight. If it was normal to the Earth's
axis, but anchored at the Pole - ie leaving the Earth's surface at a
tangent - there would be 6,381.1 km further to travel up the thing to reach
GEO.

 

So this is a learned behaviour?

 

The average Equatorial radius of the Earth is 6,378.1 km. If you plant the
thing at the Pole instead of the Equator, everything going up and down it
has to go that extra distance to reach GEO. You also have to build that
extra length of structure, at fabulous cost. Why the **** would you want to
do that?

 

He built it on a mountain in Sri Lanka, but "moved" Sri Lanka nearer the
Equator.