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Monuments are monumental. Hence the name "monument".
What if.......
We had a really tall pillar in geosynchronous orbit? It would be so tall that the bottom of the pillar floated 10 feet off the ground, while the top reaches WAAAAAAYYYYY out there into space, utilizing the centripital force
to keep it from touching the ground.
For those who don't know what geosynchronous means, it means that it orbits the earth and stays above the same patch of ground all the time.
And evilmathgenius, it could easily be anchored to the ground. So your mfd is removed. Thank you.
The Audacious Space Elevator
http://science.nasa...2000/ast07sep_1.htm
A very nice page from the NASA web site. [st3f, Oct 05 2004]
Centripetal vs. centrifugal force, (momentum)
http://www.pbs.org/...ecars/petlfugl.html
[RayfordSteele, Oct 05 2004]
[link]
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Centripetal force is actually what would keep it from flying away. Momentum is what keeps satellites from falling to earth.
Anything with its center of mass far out enough to stay in orbit and yet still 10 feet off the ground at the end would be very very large. It would exert a significant gravitational field, block out the sun for some parts of the planet, mess with weather patterns, and possibly destroy all human life. |
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Arghhh! That is what I said! Centripital force is momentum that keeps the water in the bucket when you swing it around. |
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It wouldn't be that catastophic either. It would only be about 10 feet wide. |
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No, centripetal force is not momentum. In the bucket-swinging scenario the centripetal force is you pulling on the bucket and the bucket pushing the water towards the center of the circle. Momentum keeps the water from falling out of the top of the bucket. In orbit centripetal force is the force of gravity on the satellite. Centripetal force always points to the center of a circle, not out of it. Trust me, [DesertFox], I know my physics. I'm an engineer. |
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I second your [m-f-d], [contracts]. Very bad science. |
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//Anything with its center of mass far out enough to stay in orbit and yet still 10 feet off the ground at the end would be very very large. It would exert a significant gravitational field, block out the sun for some parts of the planet, mess with weather patterns, and possibly destroy all human life.// |
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Sounds cool, actually. Just not enough truly destructive mad science out there. |
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I think this might actually work (if it was lighter and
smaller near earth...very small) , but the balance issue
would be horrible. Anyway + |
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Oh, and [contracts]-
I have language I use when talking to other engineers, and I have language I use when talking to non-scientific types. Take a guess at which one I picked and why : ) |
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I don't see any thing wrong with the
science. This is just a space elevator
which doesn't actually touch the
ground. Have a google around for
"space elevator" and, if you like "arthur
c clarke" just to narrow down the results
a bit. |
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Not bad science, just old science. So,
why haven't we built a space elevator
yet? Last I heard, we don't yet have
materials with a high enough strength
to weight ratio. |
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contracts: can you have a rethink on
your MFD? |
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[added link to a nice NASA page about
space elevators] |
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[st3f]- My main problem with this idea is not the sticking up way into space, its the "floating 10 ft. off the ground." I've heard of space elevators, but those would be anchored to something. If he makes this a monument that is anchored to the ground, I'll take back my second to the [m-f-d]. |
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Since there's no vertical force at the
base of a space elevator, the only
reason to anchor it is to overcome shear
forces caused by wind. The most
practical way to overcome these would
probably to anchor the cable (preferably
to a wide base), but I can think of three
other ways of countering them off the
top of my head, none of which involve
the cable touching the ground. |
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I have no problems with your knowledge of physics [evilmathgenius]. But I work in Quality Assurance, and it's ill-advised to use the phrases [trust me] and [I'm an engineer] in the same paragraph. |
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Ha. That also depends on who its being said to. |
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Yep, no bad science here, except that the balance would have to be unbelievably precise. Winds would upset it too much to remain stable. |
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The only reason we haven't built a ground-anchored space elevator yet is that we don't have the materials available. Research has shown that buckytubes are strong enough, but we haven't yet been able to manufacture them in sufficient length or quantity to build a functioning space elevator. In due time, someone will figure out how to economically manufacture usefully long buckytubes, and it will begin a whole new chapter in high-strength composite construction, leading eventually to cheap access to space. |
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Oh, and re: //any more than Earth will orbit the moon//, which body orbits another is merely a convention, usually dictating that the smaller of the two orbits the larger. In physical terms, neither orbits the other, they both orbit their combined center of mass. It just so happens that when the masses are significantly different, the common center winds up fairly close to the center of the larger body. |
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Wind should cause this pillar to tumble or rotate about its center of gravity which is geostationary, causing the structure to turn like an immense windmill. As the ends whip by a large magnet on the ground, they could generate energy to help keep it in orbit. Of course north-south winds might knock it out of its path over the equator. |
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Not bad science. This is very good science. It is a lot like how a space elevator that they are proposing at NASA would work. |
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Only, the space elevator isn't made of a very large very heavy obelisk-like pillar that would never support its own weight, throw the earth's rotation into a oblong elliptical dance, and break into a zillion pieces under the strain. |
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Ahh, but I never said that the pillar was solid or made out of something heavy. It could be made of something really lightweight with some heavy metal objects attached to the outer end. |
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So, then it's not a pillar, it's just a carbon nanotube thread. Which is just PopSci re-hashed. |
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No, I was pointing out that it didn't have to made of solid lead or any other dense substance. |
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The part that is hanging down would have to have a phenomenal strength-to-weight ratio, as you have 36,000 km of material to support. Regardless of how light the material you use is, the bit at the top has a stupendous weight hung off it. |
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Ahh, but carbon nanotubes are very, very strong. |
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They are planning a space elevator made out of this stuff. They wouldn't unless the tensile strength was great enough for the weight problem. |
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No, it doesn't need to be anchored. It can float , because it essentially hanging from orbit. |
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Nor will it exert a notciable gravitational force, that's just silly. |
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//They are planning// Once 36,000km nanotube cables can actually be made, yes. At the moment, we're limited to a few millimetres in length. |
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Yes, but this is a plan, too. As is every idea in the 1/2bakery. |
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Why would this thing have a huge
gravitational effect or destabilise earth's
orbit? How long would it have to be?
And what would its mass be compared
to, say, your average Alp? |
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//The part that is hanging down would have to have a phenomenal strength-to-weight ratio, as you have 36,000 km of material to support. Regardless of how light the material you use is, the bit at the top has a stupendous weight hung off it.// |
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Actually, the zero point would be at the center of mass. Both the part hanging down (moving rotationally slower than the correct orbital velocity at a given altitude = gravity pulls you to a lower orbit) and the part "hanging" up (moving rotationally faster than the correct orbital velocity at a given altitude = centrifigal force pushes you to a higher orbit) will be attempting to pull away from the middle. |
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Have a hypothetical super-strong-material bun + |
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.........picturing this thing coming unmoored from it's geosynchronous location and ponderously sweeping across the countryside. |
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There would be a website and periodic traffic reports, monitoring it's path and progress. |
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"How're the freeways looking, Susan?" |
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"It's really ugly on the 805, Jim. The GSM has everything halted at the merge, and it's backed up all the way to the 8." |
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I'd love to be there when the exact spot the GSM is located goes from 1200 hours to 1200:00:00:01. A box of shadow the size of a breadbox shifts to cover to the horizon. |
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More Excellent. Mexcellent. |
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[normzone], it will stay at the same position. It will also have to be somewhere at the equator. |
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