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Astron
Hello everyone.
As far as I see there are many well-educated people here so it's the best place to submit the question which bothers me.
[sensored, I'm not allowed to post liks here ]
and I cannot get a simple thing about this technology. Very simple thing - a cargo has its speed 0 m/s at the Earth's surface, and a satellite at GEO has speed at least 8000 000 m/s. At the end point (GEO) cargo would have the same speed as the satellite. Question: where the cargo gets energy to speed up? I see only one answer: it will slow down the Earth and the satellite. Regarding the Earth I think it is massive enough to do not notice any possible slow down from the cargo. Regarding the satellite - it could be slowed down significantly if the cargo has a big mass. So the satellite will lose its speed and the whole idea is wrong.
Am I right? I want to believe in such a perfect idea as Space Elevator but it must have some tricks to be a working thing.
Could anyone here explain me where Space Elevator gets energy to speed up a cargo?
Thanks in advance and excuse me for poor English
AlphaNumeric
The angular momentum increase of any cargo will be 'stolen' from the Earth itself via the torque due to the elevator itself. The satellite won't lose velocity because it too is being accelerated along by the Earth, via the elevator.

There are design issues with how much torque can be applied via the elevator and how much this will cause it to bend and how strong it will need to be but this is all stuff that has been considered. The payload moves up the elevator so slowly (relative to it's length) that the variation in speed of the satellite and the bending of the elevator would be small enough to be within structure safety limits.
kaneda
There are many problems with such an elevator. While there might be a material strong enough to stand up for untold miles under it's own weight, it then has to lift up other substantial weights. A slow process as AN points out so it would get very little use.

While a very thin line would have almost no wind resistance, a cargo would and high up, the jet stream is very fast (upto 400 miles per hour). There is also the problem of ever lower temperatures (at plane cruising height it is -70.C) which can affect lines and make them brittle, so useless. There is also the point that the line would probably be a great earth for electricity with a continual high current flowing to it's anchor point. It may be better as a free source of energy rather than a way of lifting things into orbit cheaply.
Corvidae
QUOTE
A slow process as AN points out so it would get very little use.

Bring the cost of launching material down to \$10/lb instead of \$100/lb and it will get a LOT of use, regardless of taking a couple days to reach the top.

It will generate some power as well, but nothing spectacular. The idea to run a wire up to the ionosphere is about a century old. It's a nice source of continuous power, just at a fairly low voltage/amperage. It should be enough to power some warning/running lights on a space elevator, but doubtful it would be helpful in lifting the cargo.

As for the cable material, the real problem is weight. We could build it out of steel cable if we wanted to...If I remember right it'd take a cable about a mile wide, tapering down to a 1/4" at the base. Structurally it could support the weight of the cable. Economically it's complete insanity to launch that much steel, and no one wants to even begin to think what happens if it falls down. Point to point, the stresses on the cable can be managed easily enough. Unless we discover some miracle material it's going to end up being a tapering ribbon/cable set up. It's just finding a material that can do it and be in some realistic weight class.

I'm still waiting to see some alloy nanotubes myself. The straight carbon tubes are a pain to mass produce, and they don't attach well to anything for making ropes/cables. They're making progress with them, but I'm betting someone else comes along with a better material.
Mr. Robin Parsons
And you are going to get across the thermosphere with it's beyond 1000 C temperature How?

Astron Post the link and remove the > http://www < blue part from the address...it should work.
kaneda
Carbon fibre is very conductive and the line is going right through the area where all lightning comes from. The line will become a very live wire as it is a direct line to earth, far better than just air.

There is a massive cost in setting this up (besides R&D) and it is VERY limited in what weight it can lift up. What is it going to lift? Endless bits and pieces?
Corvidae
QUOTE (Mr. Robin Parsons+Oct 24 2007, 06:12 PM)
And you are going to get across the thermosphere with it's beyond 1000 C temperature How?

Re-read the link you posted and you'll notice that the thermosphere is incredibly thin. Micro meteors are a bigger danger than anything the thermosphere is going to do.

Again, it's not really an engineering or environmental problem. We know how to build something strong enough. The problem is cost and weight. What's the point of trying to build something that will cost more than the planetary economy? It's fairly certain to fail. So they have to find something they can get into orbit cheaper, and maintain more easily.

Oh and Kaneda, it's not certain, but many think that the constant power drain caused by the cable would prevent lightning strikes from forming. And either way, the cable can be pulled up in case of a storm. The counter weight on the elevator means it wouldn't take much thrust to move the cable up and down the small amount it would take to dodge a storm.

Also the counterweight would partially determine the maximum loading on the cable. It should be able to lift 1-2 tons of cargo at a time (not including pod weight). I've seen much larger estimates, but they also involved massive duplication on the cables. Running 16 or 32 cables might even be the way to go for more capacity, but I think it'll really depend on the cost of the cables.
Astron
Thanks AlphaNumeric, you gave the answer I was looking for. I was really curious about the source of the torque for the cargo.

Here is the link where I saw the article, nothing's special there, I'm just trying to find out if removing of >h_t_t_p_:_/_/_w_w_w < works ".nature.com/news/2007/071019/full/news.2007.180.html"

Thanks!

Mr. Robin Parsons
QUOTE (Corvidae+Oct 25 2007, 09:52 AM)
Re-read the link you posted and you'll notice that the thermosphere is incredibly thin.  Micro meteors are a bigger danger than anything the thermosphere is going to do.
Yes and the energies at work there develop High temperatures....Quite high....

That starts all sorts of engineering problems, all sorts....

Do you know why the Space shuttle has 'heat proof' tiles?

QUOTE (Corvidae+Oct 25 2007, 09:52 AM)
Again, it's not really an engineering or environmental problem. We know how to build something strong enough.
So said the people who built the Titanic.....

Wouldn't it be simpler simply to have an anti-gravity or gravity Empowered to flight craft-ship-shuttle?

Edit

Astron when you remove the Http you still need to use the [Url={Insert address here} ]Insert name here[/url ] 'tags' for it to link.

(I) copy-pasted that link and it is a subscription site, ergo we (a generality) have no access to it....
Grumpy
Mr. Robin Parsons

QUOTE
Do you know why the Space shuttle has 'heat proof' tiles?

The real question is, do you???

The ceramic/ablative tiles on the shuttle are there to resist the high temperatures of reentry, when the SPEED of the shuttle through the air generates high temps, not because of some "thermosphere". When an object enters the atmosphere at anything like 24,000 mph(mach 25+), it is the friction with the air that generates heat. The air is so thin at the heights where it's temperature starts to get dangerous that the total amount of thermal energy transfered is very low.

As to the generating capacity of tethers, look into the shuttle experiments with a reel of conductor. Before they had unreeled a 1/4 of the length they took into space, the amperage got so high it burned the cable in two. If you troll a cable from a spacecraft the magnetic field of the Earth generates large amounts of power, any space elevator that is conductive all the way to ground level would be like a continuous lightning bolt. In any case, properly controlled, it would generate more than enough power to power itself. With maglev technology the elevator cars could do thousands of mph once above the atmosphere and could even accelerate all the way to the end and achieve speeds a significant portion of light speed, making travel to the outer solar system cheap and easy. Maybe even sending probes to the nearest stars in one persons lifetime.

IMHO the space elevator will finally free man from the gravity well that is now our prison. It should be a goal for every government on Earth.

Grumpy
Mr. Robin Parsons
QUOTE (Grumpy+Oct 25 2007, 11:44 AM)
The ceramic/ablative tiles on the shuttle are there to resist the high temperatures of reentry, when the SPEED of the shuttle through the air generates high temps, not because of some "thermosphere". When an object enters the atmosphere at anything like 24,000 mph(mach 25+), it is the friction with the air that generates heat. The air is so thin at the heights where it's temperature starts to get dangerous that the total amount of thermal energy transfered is very low.
So that is why some of them Glow? is it? Speed through an atmosphere does generate temperature, but as you admit, it is very thin 'air' up there, yet it still generates enough heat for the need of heat resistant tiles...sounds to me a bit like your argument is a little bit self defeating...

QUOTE (Grumpy+Oct 25 2007, 11:44 AM)
As to the generating capacity of tethers, look into the shuttle experiments with a reel of conductor. Before they had unreeled a 1/4 of the length they took into space, the amperage got so high it burned the cable in two. If you troll a cable from a spacecraft the magnetic field of the Earth generates large amounts of power, any space elevator that is conductive all the way to ground level would be like a continuous lightning bolt. In any case, properly controlled, it would generate more than enough power to power itself. With maglev technology the elevator cars could do thousands of mph once above the atmosphere and could even accelerate all the way to the end and achieve speeds a significant portion of light speed, making travel to the outer solar system cheap and easy. Maybe even sending probes to the nearest stars in one persons lifetime.
Sounds a bit like a Very Long 'Rail Gun' but what happens when there is a Storm on the planets face - and lightening?

QUOTE (Grumpy+Oct 25 2007, 11:44 AM)
IMHO the space elevator will finally free man from the gravity well that is now our prison. It should be a goal for every government on Earth.
Gravitationally empowered flight would probably be easier and way cheaper to engineer.

QUOTE (Grumpy+Oct 25 2007, 11:44 AM)
Grumpy
No Doubt.
QUOTE (Grumpy+Oct 25 2007, 11:44 AM)
In any case, properly controlled, it would generate more than enough power to power itself. With maglev technology the elevator cars could do thousands of mph once above the atmosphere and could even accelerate all the way to the end and achieve speeds a significant portion of light speed, making travel to the outer solar system cheap and easy. Maybe even sending probes to the nearest stars in one persons lifetime.

Grumpy,

How can something as short as a space elevator (relatively speaking) generate speeds that are a significant portion of light speed?

Rough calculation:

If you accelerated something up the elevator at a constant acceleration of 100 gs (yikes) for 1 minute you would need an elevator that went up ~ 1,000 miles but you would still only be going less than 0.0002 the speed of light.

Now its true that this (0.0002 of c) is ~ 120,000 MPH and as such is near the fastest manmade object (Helios) but still.....

Am I missing something?

Arthur

N O M
QUOTE (Mr. Robin Parsons+Oct 26 2007, 04:29 AM)
Gravitationally empowered flight would probably be easier and way cheaper to engineer.

It already works, it's called falling.

Corvidae
QUOTE (Mr. Robin Parsons+Oct 25 2007, 04:29 PM)
So that is why some of them Glow? is it?

The heat generated by our spacecraft is caused by compressing the air in front of them. A stationary cable/ribbon or tether doesn't have that problem. Thermal transfer would be slower than the thermal conductive rate of the cable.
QUOTE
Sounds a bit like a Very Long 'Rail Gun' but what happens when there is a Storm on the planets face - and lightening?

Any space elevator system will use a counterweight on the top. Meaning the entire thing takes very little to move. In case of storm, raise the cable along with anything on it. After the storm, drop it back down and re-attach.
QUOTE (->
 QUOTE Sounds a bit like a Very Long 'Rail Gun' but what happens when there is a Storm on the planets face - and lightening?

Any space elevator system will use a counterweight on the top. Meaning the entire thing takes very little to move. In case of storm, raise the cable along with anything on it. After the storm, drop it back down and re-attach.
Gravitationally empowered flight would probably be easier and way cheaper to engineer.

Star Trek transporters would be even easier, and slightly more likely at this point. Rather than wait a few centuries for someone to figure that out, I think I'll go with the elevator design that only uses the known laws of physics right now.
Grumpy

A space elevator(Beanstalk) would be on the equator and stretch beyond geosynchronous height (Above 24,000 miles) with a counterweight at about 32,000 miles(if I remember my scifi correctly). If you accelerated your space probe at 100 gs for 32,000 miles, how fast would it be going at the end??? And some designs call for 62,000 mile lengths(those without massive tether counterweights), what speed then???

Corvidae

QUOTE
Any space elevator system will use a counterweight on the top. Meaning the entire thing takes very little to move. In case of storm, raise the cable along with anything on it. After the storm, drop it back down and re-attach.

This would not be possible, the design depends on great tension between the Earth and the part of the tether beyond geosynchronous orbit to stay upright. A better idea would be to find a high mountain right on the equator(or very close) to anchor the bottom to. Then it would be above the danger zone.

The anchorage of the completed elevator would not be a single strand, rather a tube of billions of individual strands in a tube formation(something like a cooling tower, only much bigger). construction would start with a single cable carried down from orbit, but then continue like a spider builds a tubular web. Who knows, we may develop huge "Space spiders"(biological or mechanical, or a combo of the two) that extrude single molecule strands of carbon nano-tube as they climb the previous cable and travel all the way from one end to the other, making each strand a single molecule of enormous strength. This tube form could eventually even be sealed and the atmosphere removed from the interior for launching high speed payloads while passengers and other lower speed cargo travel along the outside of the tube. Normal Earth weather would have no effect on this structure, though efforts would have to be made to clean up the space junk we have already accumulated and any large pieces of stray meteorites. The tether could also be swayed sideways to miss such debris.

Science fiction??? Not any more!!! We already have the technology to do this in the next one hundred years, we just need the will and the effort to do so.

Grumpy
Mr. Robin Parsons
So first, the space shuttle, when it generated Amperage using a tethered wire, it did so by passing through the Magnetosphere, as it (the shuttle) travels at a different rate of speed then the planet below it....your space elevator is attached to the planet and travels with it as does the Earths magnetosphere, so your not getting drag though it, you are traveling with it.

Second, the laws a of physics are rather simple. although the space shuttle appears to be experiencing Zero Gravity, that is due entirely to it's forwards velocity....your Elevator has NO forwards velocity relative to the planet hence the 95% of gravities Force that is Found at 200 mile up (The Height that the Shuttle flies at ~ 320 kilometer) will effectively result in your assembly pieces being reduced in weight by 5%, or 100 Kilos on the surface will be 95 Kilos at that height.....NOT zero, not even close to it, and it is summing into all of the weight below it to CRUSH whatever tries to support it at the Bottom - as will everything else loaded on top of it until you can escape completely the earth's gravitational effect.

Your counterweight idea works only if you can get your counterweight out of the Earths own gravitational Field...Not likely to happen as you need reduce the field effect to Less then ZERO......Gm/r^2 < 0

Bye Bye Elevator.
QUOTE (Grumpy+Oct 26 2007, 12:21 PM)

A space elevator(Beanstalk) would be on the equator and stretch beyond geosynchronous height (Above 24,000 miles) with a counterweight at about 32,000 miles(if I remember my scifi correctly). If you accelerated your space probe at 100 gs for 32,000 miles, how fast would it be going at the end??? And some designs call for 62,000 mile lengths(those without massive tether counterweights), what speed then???

It boggles the mind to imagine we could build such a 62,000 mile long cable, but assuming we could, and you lifted an object at 980 m/s^2, at the end of your cable it would be going 274 miles per second.

While 274 miles per second is a blistering pace (nearly 1 million miles per hour), it is still not even close to 1% of the speed of light.

Also, without a large counterweight, (I calculate centripetal acceleration equal to only 0.56 meter/second^2 at the end of a 62,000 mile cable) how would an object of any significant mass continue to accelerate itself as it neared the end of the cable?

Arthur
Grumpy

QUOTE
It boggles the mind to imagine we could build such a 62,000 mile long cable, but assuming we could, and you lifted an object at 980 m/s^2, at the end of your cable it would be going 274 miles per second.

While 274 miles per second is a blistering pace (nearly 1 million miles per hour), it is still not even close to 1% of the speed of light.

Also, without a large counterweight, (I calculate centripetal acceleration equal to only 0.56 meter/second^2 at the end of a 62,000 mile cable) how would an object of any significant mass continue to accelerate itself as it neared the end of the cable?

"A Journey of 1000 miles begins with one step". Yes, the Beanpole would be a stupendously big project, requiring decades to begin, but it is doable, given only the will.

Most designs use an asteroid as a counterweight at about 32,000 miles. As Mr. Robin Parsons seems not to have a clue of that which he speaks about, at ~24,000 miles the orbit of a satellite is directly above the same spot on the equator, called geostationary. Anywhere above that and the satellite travels slower in a free orbit, anywhere below that and it must travel faster to remain in orbit. By being attached to one spot on Earth anything above 24,000 miles exerts a tension on the cable. I'll take you at your word on the amount of centripetal force at 62,000 miles, but your figure seems too low. But then, I am not a rocket scientist. But those who are Rocket Scientists say it is doable.

As to continuing acceleration to the end, magnetic levitation and linear acceleration. And a thousand Gs gets you above 1 %. We already have electronics that can survive that(Artillery shells). 10,000 Gs gets you 15% or so of light speed, also conceivable. And for interplanetary trips a couple of Gs gets you well on your way to Mars, etc. along with a Lithium6+Lithium6 fusion drive(see Bussard fusion drive) at one G there and back. We may not see it, but those in the future can probably plan on it. The Solar System is ours for the taking, the nearest stars are reachable and we may even be able to populate the rest of this galaxy, given a few million years.

http://en.wikipedia.org/wiki/Space_elevator

An interesting, if a little dated article+several good references.

Grumpy
Mr. Robin Parsons
QUOTE (Grumpy+Oct 26 2007, 06:26 PM)
Most designs use an asteroid as a counterweight at about 32,000 miles. As Mr. Robin Parsons seems not to have a clue of that which he speaks about, at ~24,000 miles the orbit of a satellite is directly above the same spot on the equator, called geostationary. Anywhere above that and the satellite travels slower in a free orbit, anywhere below that and it must travel faster to remain in orbit.
So something Above 24000 mi is going to go slower so, unless you get it to match speed with the geo-point it is going to cause a drag on it, and that drag will pull it down as there is no force to project it away.

A counterweight large enough will be attracted by the earth's gravity and the drag effect that will induce curvature into the tether...bringing it down.
Sapo
Centripetal acceleration, dolt.
roam

I'm seeing people harping about the raising and lowering of the cable during a storm, but what about centrifugal force. If the cable is released from the earth wouldn't the counterweight fly off?

The pod would also be buffeted by radiation and space debris (remember the crater in the space shuttle window from a fleck of paint) to properly shield the pod would drastically increase the weight of the pod, increasing the tension of the cable, and so on and so forth

Mr. Robin Parsons
QUOTE (Sapo+Oct 26 2007, 09:13 PM)
Centripetal acceleration, dolt.

Oh so the planet is going to drag this thing up to speed?? from above the planned path of flight?? or from below it??

Try thinking......the acceleration will not be as Perpendicular to (As from) the planets face, not if you are counting on Centripetal acceleration.....Sap 0
Mr. Robin Parsons
And someone mentioned 62,000 miles out, that is roughly half way to the moon so it's (The Moon's) gravitational affectations upon your counterweight are going to snap (Tension stress) that 'string', possibly generating a HUGE electrical Discharge that trails down from it as it flies off into space....

P.S. (I) have balanced a thirty to forty Pound car wheel Assembly with a 0.25 Oz weight...any addition to the earth's gravitational Profile - is a permanent one - that acts over a Long period of time and Will eventually, sooner or later, affect the planets Path through space...you have no right to change that, Nor to Risk Changing that!
kaneda
It would be incredibly difficult to run out such a line, especially with it moving at so many different speeds and stationary on the ground. I don't think it would be possible.

Could we use helium balloons to lift something high enough to a floating base from where a rail gun could shoot it into orbit since it is above much of the atmosphere so would hopefully survive friction intact?
Grumpy
Mr. Robin Parsons

You know very little and, evidently, you understand even less.

kaneda

The first tether would be built in geostationary orbit. Then it would be let down from there as the counterweight was used to control that descent. Once the first cable was anchored the rest would be constructed by "spiders" climbing up and then down the first cable, trailing single molecule strands from the ground to the end and back. Such spiders would probably be a permanent fixture as repairs would be needed throughout the life of the Beanstalk. As the construction continued, the single strand would grow into a tubular "barrel" of mono-molecular carbon fiber. That way, any punctures and broken strands would not affect the entire structure and repairs could be made.

Lithium, the lightest metal, and also the most abundant on Earth, makes both a good radiation shield and, one day, an excellent fusion fuel(little to no radiation), it can also be the primary structural component of a spacecraft(we don't use it much here on Earth because it is EXTREMELY reactive)and can store HUGE amounts of electrical power/weight. In vacuum, with no atmosphere to react with, it would be nearly ideal.

Grumpy
El_Machinae
I'd recommend purchasing a book on the Space Elevator. The reading is really good, and it's a good way of learning some physics, too.

Plus, it gives the authors (who're likely trying to be entrepreneurs in this field) some moral support. They're putting their sweat and tears into this thing that very well could change humanity's destiny.

\$20 or so isn't such a bad way of helping out.

Corvidae
QUOTE (kaneda+Oct 27 2007, 02:04 PM)
It would be incredibly difficult to run out such a line, especially with it moving at so many different speeds and stationary on the ground. I don't think it would be possible.

Technically, it's floating above a stationary point on the surface. The stresses on the elevator have to be considered from the point of it being a pair of connected satellites. The original mathematics for the set up didn't include lowering the bottom satellite all the way to the surface. Their idea was simply to use the pair of satellites to move cargo from low to high earth orbit.

It was quickly figured out that getting into an orbit that would allow connecting to the lower satellite would take a lot of fuel and in the end, wouldn't save much. Later on it was found that, it didn't matter how low the lower satellite was, the set up would still work.

So when you look at a space elevator, the point where it is connecting to the ground is actually the lower point of a satellite that is orbiting in geostationary orbit. With enough fine tuning it could be connected to the ground with a strip of duct tape, since the part at ground level is actually just floating there anyway. (More likely we'll need a fairly strong contact point, since we're not that good yet.)

That's why we can't build a space elevator from the ground up. The bottom of the elevator is actually supported from the top(Well, a central point around 22,500km up). And as difficult as making a tether is, it would be far more difficult to create a base foundation capable of supporting it, or controlling any kind of lifting system that wasn't in orbit itself.

Parsons - Try balancing every tire on the planet simultaneously with that same .25oz weight. There are serious orders of magnitude between balancing a tire and balancing the planet. And 62,000km is less than 20% of the way to the moon, nowhere near half. I'd be more worried about hitting the other satellites in geostationary when putting the elevator up, than with overbalancing the planet or tidal forces caused by the moon.

I forget who mentioned it, but the reason they're looking at using a floating platform instead of a mountain top is because there are no significant mountain tops on the equator. Going north or south of the equator to reach one ends up being more difficult than going the last 3 to 5 miles to sea level. They also took into account regional security. A space elevator in a war zone is a really big problem that no one wants to risk.
Mr. Robin Parsons
Lets see, in the real world when the planet spins on it's axis the Tether is going to go from sunlight to shadow, and back again, every day, thus it will be experiencing heating and cooling effects as a result of the nearly 400 C difference in temperature between night side and daylight side.

If you get One micrometer of expansive or contracting effect in a length of one meter of your tether then you will get a meter per kilometer, and a Kilometer per 1000 kilometers or 40 KILOMETERS of thermal contraction (or expansion) @ the 40,0000 kilometers of length that's getting you to geo-stationary......and all of that is occurring at a differentiated rate along the tether as it passes from light to dark.

Couple that to the Solar wind effect upon your counterweight such that, every time it enters into the sunlit side it is being pushed back, till it hits the Zenith of High noon where it will be being pressed-pushed directly towards the Earth by the Solar wind, followed by a period of acceleration that will maintain a higher speed longer then the slowing effect simply because it will go speeding into the Night time side absent of other effect, hence we have an slight accelerating addition on every orbit inducing a harmonic in the planes orbit.

Follow that with the other reality that if you are going out 62,000 mile you have gone past the limits of the Magnetosphere such that the far end of your said conductive line will not be charged, until such time as the equinoxes where it will then have to pass through the magnetosphere's Tail (as formed by the Solar Wind) suddenly Charging your entire Tether - end to end - every night for a period around each of the equinoxes....

Major engineering challenges, really major, never-mind the induction of a new Planetary rotational harmonic simply due to the above orbital variances will re-direct the planet from it's path after enough repetitions....

BYE BYE Elevator!
Mr. Robin Parsons
QUOTE (Corvidae+Oct 27 2007, 02:27 PM)
(SNIP) - Try balancing every tire on the planet simultaneously with that same .25oz weight.  There are serious orders of magnitude between balancing a tire and balancing the planet.  And 62,000km is less than 20% of the way to the moon, nowhere near half. (SNoP)  I'd be more worried about hitting the other satellites in geostationary when putting the elevator up, than with overbalancing the planet or tidal forces caused by the moon.
The ratio of weight to effect on the tire is 2560:1

QUOTE (Grumpy+Oct 26 2007, 12:21 PM)
(SNIP) A space elevator(Beanstalk) would be on the equator and stretch beyond geosynchronous height (Above 24,000 miles) with a counterweight at about 32,000 miles(if I remember my scifi correctly). If you accelerated your space probe at 100 gs for 32,000 miles, how fast would it be going at the end??? And some designs call for 62,000 mile lengths(those without massive tether counterweights), what speed then??? (SNoP)
The moon is roughly 125,000 MILES away ....half of that is...?
QUOTE (Mr. Robin Parsons+Oct 28 2007, 07:32 AM)
The moon is roughly 125,000 MILES away ....half of that is...?

Greatest distance of Moon from Earth = 252,586 miles

Shortest distance of Moon from Earth = 221,331 miles

Arthur
Grumpy
Mr. Robin Parsons

As Ben Franklin said, "It is better to remain silent and be thought a fool, than to speak and remove all doubt."

Wise words.

Grumpy
Mr. Robin Parsons
QUOTE (adoucette+Oct 28 2007, 07:46 AM)
Greatest distance of Moon from Earth  = 252,586 miles Shortest distance of Moon from Earth  = 221,331 miles
Ooooops thanks....IIRC.....(Where's the smilie for embarrassed)

Is that why your are going to stop talking - now - Grumpy? (I)' m not going to - as one error - does not - a strong intellect - Break!
kaneda
Grumpy. I don't know what the wear and tear would be on this but a break anywhere in the line could be a bit of a disaster as it would be a nightmare job to replace it. Would the line be "in stages" to make something like this easier to do?
Mr. Robin Parsons
QUOTE (kaneda+Oct 28 2007, 08:52 AM)
Grumpy. I don't know what the wear and tear would be on this but a break anywhere in the line could be a bit of a disaster as it would be a nightmare job to replace it. Would the line be "in stages" to make something like this easier to do?
Given the 24,000 mile to Geostationary - a break in it at 20,000 miles - would be disastrous - as the 20,000 Miles of Wire(?) came crashing down across the planets face, the end piece only reaching it's terminal velocity near the very end of it's descent and developing an enormity of accumulated acceleration (Force) at that point...
Grumpy
Mr. Robin Parsons

I've yet to see a post you have made where it seemed you knew what you were talking about, on any subject, in any thread. So "a strong intellect"??? Not so much.

kaneda

QUOTE
Grumpy. I don't know what the wear and tear would be on this but a break anywhere in the line could be a bit of a disaster as it would be a nightmare job to replace it. Would the line be "in stages" to make something like this easier to do?

Thus the need for a tubular, massively redundant, structure and the continuous adding of fiber throughout the life of the structure. Also, self destruct charges could cut the cable at safe points to limit it's impact in case of failure. Any breaks below 24,000 miles would reenter the atmosphere(at least the lower parts) on the first orbit, above that point it would be in a stable orbit(at least for a while). Carbon fibers would burn up easily so the only dangerous parts would be the first thousand miles or so. If the base was water based close to the west coast of the Americas, or in Panama, that would fall into the Pacific Ocean.

Most of the materials and technology to start construction exist today. It might take 100 years to build a complete tower, but it would become useful in less than ten. We could actually see one started in our lifetimes, some say within 10-15 years.

Grumpy
Mr. Robin Parsons
Grumpy that is because it requires intellect to recognize intellect, obviously what your problem (actually) is...... can't recognize what you don't have....
Charles Lee Ray
Ignore the feverish bleating urinal head Grumpy .... be better than he.
Mr. Robin Parsons
First time (I) have every seen someone advise that their advise - be ignored and tell that the listener will be better than they for following it....Oye what a Futz!
kaneda
Grumpy. Such a project would need a serious amount of time and effort, but most of all, money. I think it would have to be an international project. The difficulty would be financing a working model to show it was feasible. Maybe the first stage (a thousand miles?) coming down from space?
Grumpy
kaneda

QUOTE
Grumpy. Such a project would need a serious amount of time and effort, but most of all, money. I think it would have to be an international project. The difficulty would be financing a working model to show it was feasible. Maybe the first stage (a thousand miles?) coming down from space?

Yes, it will take a worldwide effort and lots of money, but this is all encompassed by the word "will".

And, unfortunately, it is not a project which can be done piecemill. It's like trying to pull a climber from the bottom of a 1000 ft cliff, it does you no good to throw down the first hundred feet of rope, you must have all 1000+ feet before you can effectively do it.

The other thing that will be necessary is a permanent presence in space and on the moon(the most efficient source for the materials). The tether will have to be constructed in orbit(maybe at the Lagrange point between the Earth and moon). Firing packets of material by linear accelerator from the surface of the moon so they arrive at low speed at this point is tricky but doable. Solar power to manufacture the cable is unlimited this far away from the shadow of Earth(preprepared materials made on the moon would help) and it could then be moved to geostationary orbit and lowered in a controlled fashion from there. The main thing we need to develop is the ability to create mono-molecular strands of carbon fiber or Bucky tube thousands of miles long. Shorter pieces have already been fabricated and tested, they are the strongest materials ever made and have already demonstrated the required tensile strength.(160 kpa, steel is about 20 kpa)A cord of this stuff no thicker than a lead for a mechanical pencil(0.5 mm) could easily pick up your car!!!

Grumpy
EMPulse
Wouldn't the cable snap from its own weight? the longer the cable gets in the gravitational field, would it be heavier to its own length weight?
Grumpy
EMPulse

QUOTE
Wouldn't the cable snap from its own weight? the longer the cable gets in the gravitational field, would it be heavier to its own length weight?

The tether would be tapered in cross section (of it's wall) according to the exact stress level for that height.

The thinnest(in wall thickness) at the bottom, where it attached to the Earth, thickest some 20,000 miles above that, thinner as it neared 24,000 miles and pretty much the same thickness to the counterweight(at about 32,000 miles) or tapering smaller all the way to 64,000 miles(a counterweight would not be needed at that length). The inside diameter of the finished elevator would be the same all of that length(think of a gun barrel,a very big one).

Grumpy
Sapo
Fascinating. I'd always thought the car would ride the outside, like a monorail. I suppose it'd be easier to lay up all that fiber from the outside, though?
N O M
Given the time it would take for a car to go the length of the elevator, there would probably be several cars on the cable at a time. This would also require seperate rails (barrels?) for up and down.
Grumpy
N O M

QUOTE
Given the time it would take for a car to go the length of the elevator, there would probably be several cars on the cable at a time. This would also require seperate rails (barrels?) for up and down.

For a while at least all traffic would be one way, up. Atmospheric reentry is much more cost effective for all downward traffic. It's easy to get down, hard to get up. The completed beanstalk would probably cover a football field and have many tracks and could spare one for personell transfer, but cargo would just fall down to it's destination shuttle style, but the starter kit is much smaller(single strands) and have one way traffic for the first few decades at least, mostly the "Spiders" that drag the mono molecular strands from the ground up the cable to the end. Once a tubular structure is established the spiders keep up the job, making it more and more redundant and more capable of absorbing damage long enough for the spiders to repair it, and capable of lifting heavier and heavier loads and using mag lev technology to launch payloads out to the outer solar system.

Grumpy
N O M
Fair enough. Except, couldn't the breaking energy from downward traffic be used to help accelerate the upward traffic? I suppose power need not be a problem since all you would need to do is include plenty of solar panels, so maybe it isn't needed. It might still be safer to use downward cars in the elevator than using shuttles.

You suggest "spiders" dragging the monomolecular cables up from the ground. Wouldn't it be easier to grow these in orbit? They could be fed down the tether directly as they are grown. I don't think dragging these cables up the outside wouild be ideal either. The wind resistance on these fine threads would be enourmous. If one fell off the elecator, it would be very dangerous. I'd suggest the growing layer below a toughened skin, rather like the bark of a tree.
Mr. Robin Parsons
QUOTE (Grumpy+Oct 29 2007, 02:09 PM)
(SNIP) The main thing we need to develop is the ability to create mono-molecular strands of carbon fiber or Bucky tube thousands of miles long. (SNoP)
And the WIKI page Adoucette linked said by 2010...three years, do you figure it will get done by then?
visual
actually we don't need materials that tough... it can even be done with the artificially produced diamonds that we can make already.
it is just hell of expensive.
http://www.thespacereview.com/article/916/1

and no, it surely won't be ready in 2010 - but the contest's purpose is just to promote the idea and to show it is feasible - for this i think the deadline they gave themselves is adequate.
Astron
Great! I did not think I'll get so much interesting information about the matter. It seems here is the best place to read about these things.
I want to say why I was interested in a power source to speed up cargo in a Space Elevator. One of my friends told me once that it is possible to build a huge magnet, place it on South or North Pole of the Earth and use power of magnetic field of the Earth to lift this huge magnet up to any height. It would be possible to lift it up but the problem is not to lift it up, problem is to speed it up.
But in case of using counterweight by an Elevator it seems that it is a different story.
Corvidae
QUOTE (Astron+Oct 30 2007, 03:39 PM)
One of my friends told me once that it is possible to build a huge magnet, place it on South or North Pole of the Earth and use power of magnetic field of the Earth to lift this huge magnet up to any height.

Unfortunately the mass of any magnet large enough would be too large to lift. The problem with using the earths magnetic field is that while it's very powerful, it's also dispersed across a huge amount of space.

It's the same reason we don't put coils in orbit to harvest energy for satellites. The size and weight of the coil needed to get a useful amount of power, far outweighs the amount of energy it would take to put the coil up there.

Even a space elevator will need solar panels at the top and a power plant of some sort at the bottom. Seeing as they're planning a floating platform, a free floating wave generator will probably be the most efficient.
Grumpy
http://www.spaceelevator.com/docs/acclarke.092079.se.1.html

Sir Arthur C. Clarkes 1981 lecture on the space elevator.

N O M

QUOTE
You suggest "spiders" dragging the monomolecular cables up from the ground.

The ideal solution would be a bioengineered spider that could manufacture, spin and attach a fiber as it climbed the first cables(which would be manufactured in space), that could survive the vacuum of space, or it's equivalent mechanical device. Not only for the initial building, but for repairs and maintenance. Carbon is easily handled by biological organisms, and it could carry both oxygen and raw materials for the strand in the form of solid carbon dioxide(dry ice), and be refueled(or fed) once it gets out of the atmosphere. Whatever, a great deal of "Bootstrapping" would be required.

Grumpy
I'd think the first (or first few) cables would be manufactured on earth, launched into space and then dropped down.

Then, climbers could cart more earth manufactured cables up to the space platform.

The low weight of each individual strand shouldn't make that an issue.

I have yet to see a detailed description of a viable method for powering the climbers however.

Arthur
N O M
The only problem I see with the spiders, is that the amount of mass they would be adding to the cable wouldl be miniscule. One long molecule per spider per trip. That would take either a lot of spiders or a lot of time.

That and the possiblility of these spiders going rogue. Monomolecular webs would be a tad dangerous.
The climber size could increase with each trip.

Arthur
N O M
I doubt we'll be able to bioengineer anything to survive in vacuum within the next century. Miniature robots would do the job adequately. By the time we are ready to build a space elevator, we will be quite proficient at making robots for space applications since it will be mostly robots doing the hard work on the moon.
Grumpy
Nom

Each "spider" could be capable of several thousand individual strands, perhaps sewn into a matrix as spiders do silk. Drag line silk is one of natures strongest fibers, carbon monomolecular spider web could be extremely strong. And quite dangerous in the wrong hands(It would make a hell of a good blade capable of cutting almost anything)

Adoucette, you are correct that may be possible.

Grumpy
N O M
QUOTE (Grumpy+Oct 31 2007, 10:58 AM)
carbon monomolecular spider web could be extremely strong. And quite dangerous in the wrong hands(It would make a hell of a good blade capable of cutting almost anything)

That's what I thought. It would be invisible too. you wouldn't want the wind blowing a few spiders off dragging the line behind them.
Mr. Robin Parsons
And any tug on the planet, especially a regular or a timed one, would - over time - change it's (the planets) course through space.

That makes it horribly unsafe to even try.
visual
QUOTE (Mr. Robin Parsons+Oct 31 2007, 12:27 PM)
And any tug on the planet, especially a regular or a timed one, would - over time - change it's (the planets) course through space.

That makes it horribly unsafe to even try.

this is ridiculous. by the same logic, we better not move around too far to avoid changing the planet rotation...

and i am sure you realize it - the momentum of our planet is orders of magnitude greater than any change we could cause; also once we start regular use of the beanstalk in both directions, our own changes will be negating themselves.
Mr. Robin Parsons
QUOTE (visual+Oct 31 2007, 08:49 AM)
this is ridiculous. by the same logic, we better not move around too far to avoid changing the planet rotation...
And how would that affect the planets motion??

QUOTE (visual+Oct 31 2007, 08:49 AM)
and i am sure you realize it - the momentum of our planet is orders of magnitude greater than any change we could cause; also once we start regular use of the beanstalk in both directions, our own changes will be negating themselves.
Place a stone at the entrance-way to your house, rub it five times every-time you enter or leave, in a year or two you will have rubbed off a smooth surface to what otherwise appears as an impervious surface.

Get a wire out into space, tug on it regularly and the motions and energy will not disappear, but will eventually result in an induced motion.

One Quarter of the way to the moon means the moon's gravity will be affecting either the wire, or the Counterweight, or both - as it passes in front of it and especially when it passes behind the earth on the opposite side of where the counterweight or wire is.

Very difficult to maintain that orbit (Geosynchronous) over time, when a weight (Wire) is attached to your satellite - descending down to the earth's surface.

How much does this wire weigh? and what volume of space does it take up as per transporting it into space in the first place? Current cost of lift is what?? \$10,000.00 per kilo?? @ 10 grams per meter it weighs in at 10 Kilos per kilometer so 40,000 kilometers weighs in at 400,000 kilos...can you do the rest of the math?
visual
each time we launch a payload even in a traditional way, it still alters the planet's momentum, same as the case with the beanstalk would be. if you don't have a problem with normal rockets, you should stay quiet in this case too.
the insignificant changes that we can cause are so... well... insignificant, that even magnified millions of times they still won't matter.

QUOTE (Mr. Robin Parsons+Oct 31 2007, 01:49 PM)
And how would that affect the planets motion??

if you can't see how, redo your physics course. simple preservation of momentum (angular in this case).
but what i'm saying is, in general it can't, as it is balanced in every direction. make all people only walk west and there would be an effect on earth's rotation - though so insignificant that it can be ignored.

QUOTE
Place a stone at the entrance-way to your house, rub it five times every-time you enter or leave, in a year or two you will have rubbed off a smooth surface to what otherwise appears as an impervious surface.

a correct analogy would be one where you rub off material from it when you enter, and stick on more material to it when you leave
and i wonder what part of "orders of magnitude greater" did you not understand? your "year or two" will in this case need to be a number of years with double-digit exponent...

QUOTE (->
 QUOTE Place a stone at the entrance-way to your house, rub it five times every-time you enter or leave, in a year or two you will have rubbed off a smooth surface to what otherwise appears as an impervious surface.

a correct analogy would be one where you rub off material from it when you enter, and stick on more material to it when you leave
and i wonder what part of "orders of magnitude greater" did you not understand? your "year or two" will in this case need to be a number of years with double-digit exponent...

Get a wire out into space, tug on it regularly and the motions and energy will not disappear, but will eventually result in an induced motion.

and if you tug on it equally in both directions overall?

QUOTE
One Quarter of the way to the moon means the moon's gravity will be affecting either the wire, or the Counterweight, or both - as it passes in front of it and especially when it passes behind the earth on the opposite side of where the counterweight or wire is.

if you bothered to calculate how insignificant the effect would be compared to the centrifugal force that acts on it, you'd see this is so absurd that it hurts...

QUOTE (->
 QUOTE One Quarter of the way to the moon means the moon's gravity will be affecting either the wire, or the Counterweight, or both - as it passes in front of it and especially when it passes behind the earth on the opposite side of where the counterweight or wire is.

if you bothered to calculate how insignificant the effect would be compared to the centrifugal force that acts on it, you'd see this is so absurd that it hurts...

Very difficult to maintain that orbit (Geosynchronous) over time, when a weight (Wire) is attached to your satellite - descending down to the earth's surface.

but it will not be just down - both down and up, in such a way that the forces are balanced out.

QUOTE
How much does this wire weigh? and what volume of space does it take up as per transporting it into space in the first place? Current cost of lift is what?? \$10,000.00 per kilo?? @ 10 grams per meter it weighs in at 10 Kilos per kilometer so 40,000 kilometers weighs in at 400,000 kilos...can you do the rest of the math?

the ISS already weighs more than half that, and upon completion will be almost 20% above it. people have done the math already, only you haven't.

really, go read a website ot two about the topic, they usually have a good faq section that already has most of these sceptic questions answered...
QUOTE (Mr. Robin Parsons+Oct 31 2007, 09:49 AM)

How much does this wire weigh? and what volume of space does it take up as per transporting it into space in the first place? Current cost of lift is what?? \$10,000.00 per kilo?? @ 10 grams per meter it weighs in at 10 Kilos per kilometer so 40,000 kilometers weighs in at 400,000 kilos...can you do the rest of the math?

I think they are expecting the first strands to be more on the order of 1 gram per meter.

Still the launch costs would equal nearly half a billion dollars per initial strand.

Which, I guess, is precisely why people are seriously looking at the problems and at the potential cost/benefits inherent in building a space elevator.

As you point out, at \$10,000 per kg to Geo orbit there is LOTS of financial incentive to find cheaper means of getting there.

Arthur
Mr. Robin Parsons
QUOTE (adoucette+Oct 31 2007, 11:55 AM)
I think they are expecting the first strands to be more on the order of 1 gram per meter.Still the launch costs would equal nearly half a billion dollars per initial strand.Which, I guess, is precisely why people are seriously looking at the problems and at the potential cost/benefits inherent in building a space elevator. As you point out, at \$10,000 per kg to Geo orbit there is LOTS of financial incentive to find cheaper means of getting there. Arthur
That figure is not for geo orbit - that is for regular 200 mile up orbit - geo orbit will cost more as it is farther.

Shuttle launching is not a regularly timed event, certainly not a DAILY one that will induce extra motion into-onto the planets orbit....as for orders of magnitude greater, (I) can stand beside a fully loaded supertanker and lean on it, it will move........ (I) do not weigh anywheres near what the repetitive tugging effect results add to.....
Trippy
I guess we better stop using VEEGA pr VVEGA orbits, just to keep Robin happy.

Although I must admit, some of the points that he raises are completely ridiculous.

3 elevators, equally spaced, anchored to something in Geostationary orbit.

Keep the loads balance POOF no more concerns about moving the Earth out of it's orbit.
QUOTE (Mr. Robin Parsons+Oct 31 2007, 01:38 PM)
That figure is not for geo orbit - that is for regular 200 mile up orbit - geo orbit will cost more as it is farther.

I assumed you knew the launch had to be to Geo orbit so I just used your figures.

The actual 2000 average cost per Kg to Geo was \$26,000.

Which would make the cost to launch the initial strands about a Billion \$ a piece.

(who knows how much the strands themselves will cost?)

To put this in perspective, the Cassini mission was about \$3.5 billion.

Arthur
Grumpy
Mr. Robin Parsons

Even if(and that is a HUGE if) the beanstalk had a measurable effect, do you think those of the future are not at least as smart as you are??? There are many problems that will have to be dealt with in the construction and maintenance of a beanstalk. None seem insurmountable, even given the technology available today. And those a few decades from now are projected to have doubled the available knowledge several times as compared to now. And launch costs go from 10,000\$ a kilo to nearly nothing(in comparison) once the Beanstalk becomes useful. Even to launch payloads at higher than Earth escape velocity, much less get them to Earth orbit.

Imagine a ring built around the Equator on Earth, somewhat outside the geostationary orbit(for some "Gravity") and Beanstalks connecting this structure to points all around the globe(like a spoked bicycle wheel with the Earth as the Hub, and the rim as the ring). This ring could be miles(lets say 10) in widthX180,000 miles or so in diameter. That would be 1,800,000 square miles of living area, easily accessed from the Earth, with ~ 1/4 G, unlimited power, and easy launch to the outer solar system(maglev around the rim until you are at the proper speed and direction, then let go), cargo could be caught by the reverse method. Slag from the moon(or the asteroid belt) could provide radiation shielding and raw materials(even oil, if we still need it), daylight schedules would be very similar to Earth, plants could be grown there. Larry Niven's Ring World indeed. The above could also be constructed around a propulsion module(on a smaller scale) as an interstellar space ship, or as a habitat for living anywhere in the solar system. The Cosmos is then OURS.

Grumpy
visual
QUOTE (Mr. Robin Parsons+Oct 31 2007, 05:38 PM)
That figure is not for geo orbit - that is for regular 200 mile up orbit - geo orbit will cost more as it is farther.

the difference between cost to leo and gso is about a factor of two only. not all that world-changing.

QUOTE
Shuttle launching is not a regularly timed event, certainly not a DAILY one that will induce extra motion into-onto the planets orbit....

but it can become such... we certainly do want to accomplish that eventually
doing it with the beanstalk will end up cheaper than conventional rockets... why would you call that a bad thing?
and initially we won't be using the beanstalk for much more than we are using shuttles now, anyway.

QUOTE (->
 QUOTE Shuttle launching is not a regularly timed event, certainly not a DAILY one that will induce extra motion into-onto the planets orbit....

but it can become such... we certainly do want to accomplish that eventually
doing it with the beanstalk will end up cheaper than conventional rockets... why would you call that a bad thing?
and initially we won't be using the beanstalk for much more than we are using shuttles now, anyway.

as for orders of magnitude greater, (I) can stand beside a fully loaded supertanker and lean on it, it will move........    (I) do not weigh anywheres near what the repetitive tugging effect results add to.....

i don't think it's a relevant comparison at all, and i am really sceptical about your claim that you'd have any noticeable effect on that supertanker but i'll go along with that...
your mass is in the order of 10^2, a supertanker is in the order of 10^9, the difference factor is just 10^7. still much smaller than the factor between earth mass 10^24 and what we might possibly launch to space any time soon - say 100 000 times the weight of the beanstalk itself, over many centuries, or 10^10 - difference factor of 10^14

and again i remind you that our "tugging" will be in both directions, so will neutralize itself.

don't misunderstand me here, i don't deny that the effect you describe does exist - i only want to point out to you how ridiculous it is to call it "dangerous"... or even "noticeable" at this point.
i hope you won't persist with such absurd claims.
N O M
So parsons is worried about us affecting the Earth's orbit? Just how much stuff is he expecting us to take into space?

It won't matter how much we use it, there will be far more mass coming back down to Earth compared to what is going up. Once we get lunar mining and manufacturing going well, it will also be much cheaper to send bulk items from the moon into Earth orbit than up the beanpole, regardless of how cheap a beanpole will make getting stuff to orbit.
Mr. Robin Parsons
Two directional tugging?? neutralizing itself ....How? your in a sort of buoyancy in space with great inertial movements impressed upon that....

We Pass through the Leonid's meteorites every year, that might press-push your counterweight off of geosynchronous and into a higher orbit relative to the poles.....change of inclination-tilt anyone?? and the coupled 'Season' Changes....

Three balanced? how do the three balance out the Moons affectations?? (worse)
visual
i am getting tired...
QUOTE (Mr. Robin Parsons+Nov 2 2007, 01:08 AM)
Two directional tugging?? neutralizing itself ....How? your in a sort of buoyancy in space with great inertial movements impressed upon that....

lets make it clear, are we still talking about the effect space travel will have on earth's motion in the long term? because this is what i was referring to.
my point was that payloads will both be launched and arrive back to earth, and in many different directions, so the net effect on the momentum of the earth will not grow linearly with time.

or are you talking about the stability of the elevator itself now?

QUOTE
We Pass through the Leonid's meteorites every year, that might press-push your counterweight off of geosynchronous and into a higher orbit relative to the poles.....

oh yeah, just like it affects all the other artificial satellites that we have launched, right...

QUOTE (->
 QUOTE We Pass through the Leonid's meteorites every year, that might press-push your counterweight off of geosynchronous and into a higher orbit relative to the poles.....

oh yeah, just like it affects all the other artificial satellites that we have launched, right...

change of inclination-tilt anyone?? and the coupled 'Season' Changes....

Three balanced? how do the three balance out the Moons affectations?? (worse)

under-stand anyone?? whole sentences use...
42 balanced. will not reply to you anymore?? (better)
Mr. Robin Parsons
QUOTE (visual+Nov 2 2007, 09:08 AM)
(SNIP) oh yeah, just like it affects all the other artificial satellites that we have launched, right... (SNoP)
No - Actually the ones currently in geo stationary orbit....(Best!)
Corvidae
So according to Robin here, the weight of a satellite in orbit around the planet (yes in orbit, regardless that it touches the ground) is going to alter the orbit of the planet more than the movement of all the oceans and tectonic plates sliding around with every rotation as well?

I think humans have a problem conceptualizing energy density and large orders of magnitude difference. From people wanting to use a generator powered by an electric motor for free energy, to the people thinking the earths magnetic field is going to fly them around the planet. To simply not grasping how pathetically insignificant our little planet in our tiny galaxy in our backwater of the universe really is. No matter how important it may actually be to those of us stuck living here.

I wonder if there's a way to test other primates abilities to judge the same relationships. Along the same way they studied the monkeysphere theory.

In any case, Robin, tie a shoe lace to your car and measure the difference in gas milage while randomly picking up 2 to 4 people weighing at least 150lbs each. The amount of change in the earths rotation from a space elevator will be negligible. We'll be worrying about the moon coming back down before we have to worry about any changes in our orbit due to an elevator.
Sapo
QUOTE (Corvidae+Nov 2 2007, 03:13 PM)
So according to Robin here, the weight of a satellite in orbit around the planet (yes in orbit, regardless that it touches the ground) is going to alter the orbit of the planet more than the movement of all the oceans and tectonic plates sliding around with every rotation as well?

(...some snipped...)

I wonder if there's a way to test other primates abilities to judge the same relationships. Along the same way they studied the monkeysphere theory.

In any case, Robin, tie a shoe lace to your car and measure the difference in gas milage while randomly picking up 2 to 4 people weighing at least 150lbs each. The amount of change in the earths rotation from a space elevator will be negligible. We'll be worrying about the moon coming back down before we have to worry about any changes in our orbit due to an elevator.

You give Robin credit for being a primate? Nice guy!
Mr. Robin Parsons
QUOTE (Corvidae+Nov 2 2007, 04:13 PM)
In any case, Robin, tie a shoe lace to your car and measure the difference in gas milage while randomly picking up 2 to 4 people weighing at least 150lbs each.  The amount of change in the earths rotation from a space elevator will be negligible.  We'll be worrying about the moon coming back down before we have to worry about any changes in our orbit due to an elevator.
Ahhh but it is there, and that is the danger! even a Tiny - Small amount could change the planets pathway irrevocably - and - it gains amplification over time.
G'day folks.
I agree with the majority opinion/trend hereabouts. The space elevator is our way to the solar system and thence to the stars. It may not happen in my day but, bejeebuz, if the hominids of near future don't do it, then our descendants will have to hang their heads in shame. But it will be done, because it is just such a reasonable and feasible thing to do!

QUOTE (Grumpy+Oct 30 2007, 06:31 AM)
N O M
For a while at least all traffic would be one way, up. Atmospheric reentry is much more cost effective for all downward traffic. It's easy to get down, hard to get up. The completed beanstalk would probably cover a football field and have many tracks and could spare one for personell transfer, but cargo would just fall down to it's destination shuttle style, but the starter kit is much smaller(single strands) and have one way traffic for the first few decades at least, mostly the "Spiders" that drag the mono molecular strands from the ground up the cable to the end.

Grumpy

I don't want to be picky here but I think that something far more ambitious is possible. But I also think that this evolution into space has to be accompanied by a balancing development back here on Earth.

The fact is, most people on the planet are never going to go into space. Just like most people never leave their own country, never mind migrate round the world like my family did. Migrating, for us, turned out to be a good thing to do because the weather in Oz is much better than UK, but the same is not likely to be said of space weather.

If we do things right however, everyone on the planet stands to gain from the increased knowledge and the potential for peaceful unity that a broad and ambitious global project could bring.

As far as I can see we need a project to increase the standard of living of everybody on the planet by about the local equivalent of US\$2000, as that \$2000 was valued in the year 2000. This CAN be done sustainably [see my 4th axiom for reassurance] and this will give a far more secure economic base for the size of project that is entailed in this vision for a space elevator.

So maybe a single tube or ribbon like thing may be what we start with but I'm thinking that, further on, a series of continuous belts will be able to provide up and down traffic at a couple of hundred kilometres per hour.

QUOTE
Once a tubular structure is established the spiders keep up the job, making it more and more redundant and more capable of absorbing damage long enough for the spiders to repair it, and capable of lifting heavier and heavier loads and using mag lev technology to launch payloads out to the outer solar system.

I'm thinking that tubular and tapered cables will provide fail-safe suspension for the rest of the system which will involve a series of continuous belts, which obviously can't be tapered, with each to be looped over a big wheel at its top end. Presumably all but the bottom one could be looped around the next wheel down. The ribbon/belts shouldn't get tangled because the Coriolis effect would keep them well apart.

Power for the transport would come from the very large geostationary satellite, nuclear powered probably [see the Adams Atomic Engine web site for a candidate].

Manufacture of all the big parts would probably need to happen on [or IN] the moon, but manufacture of the vast number of small parts, and pieces of machine tools etc, may need to be done on Earth. Getting many metal parts up to geostationary or Lunar orbit can be accomplished by accelerating them up a vacuum tube using electromagnetism/linear induction.

Such a launch tube, at least 20 km long, aimed up at about 45 deg, would need to be at the equator, and would be suspended within/supported by a dome/cone/pyramid shaped bubble filled with de-oxygenated air at whatever pressure was needed.

It's all possible!

Mr. Robin Parsons
Move the earth?

QUOTE (Grumpy+Oct 26 2007, 12:21 PM)
This would not be possible, the design depends on great tension between the Earth and the part of the tether beyond geosynchronous orbit to stay upright.

QUOTE (AlphaNumeric+)
The angular momentum increase of any cargo will be [B]'stolen' from the Earth itself [/B]via the torque due to the elevator itself. The satellite won't lose velocity because it too is being accelerated along by the Earth, via the elevator.
Also known as drag....

Hence two separate advocates of it BOTH recognize the effect (Pull or drag) it WILL have upon the Earth.....however minor it may appear, it is a cumulative affectation hence it will cause changes to the earth's trajectory through space...that is Un-acceptable as consequence.

Grumpy
Mr. Robin Parsons

QUOTE
Hence two separate advocates of it BOTH recognize the effect (Pull or drag) it WILL have upon the Earth.....however minor it may appear, it is a cumulative affectation hence it will cause changes to the earth's trajectory through space...that is Un-acceptable as consequence.

The cumulative effects would not even be measurable, and would only work to slow the Earths rotation by a few seconds over thousands of years, it would have no effect whatsoever on the orbit of the Earth/moon system. It's as silly a worry as it would be to worry about rising sealevel due to all the boats we put in the water!!!

Grumpy
Mr. Robin Parsons
QUOTE (Grumpy+Nov 3 2007, 11:16 AM)
The cumulative effects would not even be measurable,
That is a Lie.

QUOTE (Grumpy+Nov 3 2007, 11:16 AM)
and would only work to slow the Earths rotation by a few seconds over thousands of years, it would have no effect whatsoever on the orbit of the Earth/moon system. It's as silly a worry as it would be to worry about rising sealevel due to all the boats we put in the water!!! Grumpy
Sending it off course would be so much simpler and require less energy....and what do you base the 'slowing it down' upon rather than the potential of 'speeding it up'?

Trippy
And again, we come back to the point that all we have to do to quell some of the... Notions being promulgated on this thread is operate more then one so that these effects all cancel out.
Grumpy
Let's all pause breathless while Genius Boy...Mr. Robin Parsons...explains how slowing down the rotational speed of the Earth would affect it's orbit. Take all the time you need Genius Boy, go ahead and just try to back up this...seriously flawed claim(Hint, the orbit IS ENTIRELY SEPARATE from the rotational speed, and the rotational speed is the only thing the space elevator can affect). The Earth has survived going from a less than 10 hour day to the present 24 hour one in the last 4.5 billion years, I'm pretty sure it will survive going from a 24 hour day to a 24.1 hour day over the next couple of thousand years.

QUOTE

Yeah, like your worry about the effect a space elevator would have is silly, that was the point. The Earth's spin is naturally slowing down, always has been, nothing we could do will appreciably slow it further or speed it up(at least not in the next few thousand years). Your objection is noted, but rejected as a serious concern, and is certainly not a reason to not build a space elevator. Talk about nit picking, this is picking the nit's nits.

Grumpy
Mr. Robin Parsons
QUOTE (Grumpy+Nov 3 2007, 08:04 PM)
(SNIP) Let's all pause breathless while Genius Boy...Mr. Robin Parsons...explains how slowing down the rotational speed of the Earth would affect it's orbit. Take all the time you need Genius Boy, go ahead and just try to back up this...seriously flawed claim(Hint, the orbit IS ENTIRELY SEPARATE from the rotational speed, and the rotational speed is the only thing the space elevator can affect). (SNoP)
What was that that Archimedes said?? Oh Yes "Give me a big enough Lever And (I) will move the Earth"...

Try your persistent Tug strategy makes the Earth act as a (One) New System gravitationally (respective of the (your) Far Flung attached counterweight) thusly affecting effectively the positioning of the Center of Gravity within the Planet's core...that will have resultant effects and would induce a wobble into the planets rotation - ergo Flightpath-ORBIT through space...no mention of speeding it up or slowing it down...but that Leonid's mention does propose the opportunity to change the Planets Tilt as the Meteoroids would come at your tether and weight at an angle thusly in contacting the surfaces of (Exerting force upon) either of them, it would be pressing-pushing them off of the equatorial line of rotation....and they 'tug back' on the planet - buoyant in space

QUOTE (Grumpy+Nov 3 2007, 08:04 PM)
(SNIP) Talk about nit picking, this is picking the nit's nits. Grumpy  (SNoP)
Glad to be of service in removing your Nits! The Cheque is in the Mail??

Mr. Robin Parsons
BTW Grumpy you would have to be about the only persons on the planet who thinks that you can take something (Like a gear) that is - on it's on (spin) a Balanced system, add a weight to the outside of it, attached to it by a long cable, spin that assembly and NOT get any harmonic distortion in the spinning - compared to what that original system had....

Yikes!!

Change it's speed? not as likely, but induce a distorting harmonic into it's rotation about it's own axis....all to easy....and Dangerous!

Trippy
QUOTE (Mr. Robin Parsons+Nov 5 2007, 05:29 AM)
BTW Grumpy you would have to be about the only persons on the planet who thinks that you can take something (Like a gear) that is - on it's on (spin) a Balanced system, add a weight to the outside of it, attached to it by a long cable, spin that assembly and NOT get any harmonic distortion in the spinning - compared to what that original system had....

Yikes!!

Change it's speed? not as likely, but induce a distorting harmonic into it's rotation about it's own axis....all to easy....and Dangerous!

ONce again you mental midget, this effect can be cancled out by operating more then one elevator.

(Assuming that it's likely to be significant in the first place).
Grumpy
Mr. Robin Parsons

QUOTE

Yes, quite a bit, in fact. But it's pretty evident you know nothing, about anything.

The effect of a few thousand tons of the space elevator WILL NOT AFFECT THE EARTH ENOUGH TO EVEN MEASURE. No real wobble, no careening out of orbit, no appreciable slowing of the Earth's rotation, NOTHING. Dangerous, hardly(at least not for THAT reason). It would be the equivalent of not putting up a windmill because you're afraid it will stop the wind from blowing. The Earth would not even notice the difference.

Grumpy
Mr. Robin Parsons
QUOTE (Grumpy+Nov 4 2007, 02:17 PM)
The effect of a few thousand tons of the space elevator WILL NOT AFFECT THE EARTH ENOUGH TO EVEN MEASURE. No real wobble, no careening out of orbit, no appreciable slowing of the Earth's rotation, NOTHING. Dangerous, hardly(at least not for THAT reason).
Anywheres from 24,000 mile out to 62,000 miles out ......Know anything about conservation of angular momentum?? Apparently not.

No real wobble, you mean it would be a Fake one??
Grumpy
Mr. Robin Parsons

QUOTE
Anywheres from 24,000 mile out to 62,000 miles out ......Know anything about conservation of angular momentum?? Apparently not.

No real wobble, you mean it would be a Fake one??

No wobble at all. It would be as if you put a single strand of spider silk out from the edge of a truck tire(in vacuum, of course)and, actually the spider silk would be orders of magnitude more dense than would the space elevator, in comparison to the mass of the Earth, that is how trivial your objection is. And how dismal your understanding of scale is.

In addition, the SE would be mostly self supporting, with the tension dwindling as it approached the Earth. It would be as if it were a satellite that let a string down, the net effect would be all but non-existent.

Grumpy
Mr. Robin Parsons
QUOTE (Grumpy+Nov 5 2007, 07:12 AM)
No wobble at all. It would be as if you put a single strand of spider silk out from the edge of a truck tire(in vacuum, of course)and, actually the spider silk would be orders of magnitude more dense than would the space elevator, in comparison to the mass of the Earth, that is how trivial your objection is. And how dismal your understanding of scale is.
Three times the earth's diameter strung out into space with a counter weight at it's end...do the same thing with that truck tire - a counterweight and a Spider's Silk String to attach the weight three times the diameters distance out from the edge of the Truck wheel and you WILL OFF BALANCE IT.

meBigGuy
QUOTE
Three times the earth's diameter strung out into space with a counter weight at it's end...do the same thing with that truck tire - a counterweight and a Spider's Silk String to attach the weight three times the diameters distance out from the edge of the Truck wheel and you WILL OFF BALANCE IT.

Lets see --- the earth weighs 5.9736×10^24 kg

Lets say the tire weighs 100kg (heavy tire) and we add a 1/100 gram weight ( a pretty small weight, less than a pebble caught in a tread)

lets scale that to the earth - 100,000 grams to 1 grams = a 10^5 ratio

so if we stick a 6x10^19 kg asteroid on the cable. it would be equivilent.

The biggest known asteroid is 1 ceres at about 1 x10^21 kg. So that is a bit large (100x).

A 1.2 Km asteroid weighs about 10^12 Kg. That would be like attaching a .000001 gram weight to the tire.

Not a large effect, in my mind.

A ball of lead 82 Km in diameter would weigh about 1 X 10^19 Kg (11.3 g/cm^3) which would be like a .0016 gram weight on your 100Kg tire. (I know, it is attached at the length of a long spider web, but still, it isn;t going to have an effect. Especially if you scale the rotational velocities (I'll leave that to you to work out if you are so inclined, or are able)

I may have made a math error (way past bed time) , but you get the idea.

If we could take all the neutrons out, then it would be weightless and .... Oh, .... nevermind.
Mr. Robin Parsons
QUOTE (meBigGuy+Nov 5 2007, 09:52 AM)
Lets see --- the earth weighs 5.9736×10^24 kg Lets say the tire weighs 100kg (heavy tire) and we add a 1/100 gram weight ( a pretty small weight, less than a pebble caught in a tread) lets scale that to the earth - 100,000 grams to 1 grams = a 10^5 ratio so if we stick a 6x10^19 kg asteroid on the cable. it would be equivilent. The biggest known asteroid is 1 ceres at about 1 x10^21 kg.  So that is a bit large (100x). A 1.2 Km asteroid weighs about 10^12 Kg.  That would be like attaching a .000001 gram weight to the tire. Not a large effect, in my mind. A ball of lead 82 Km in diameter would weigh about 1 X 10^19 Kg (11.3 g/cm^3) which would be like a .0016 gram weight on your 100Kg tire. (I know, it is attached at the length of a long spider web, but still, it isn;t going to have an effect.  Especially if you scale the rotational velocities (I'll leave that to you to work out if you are so inclined, or are able)
So you seem to think that if you attach this tiny weight on the face of the surface of the tire, and then (A truck tire is roughly two + feet across) attach it to a weightless cable that is SIX feet long it will still act the same way...it won't - it will induce a wobble lots faster at Six Feet from the face of the surface then if attached to the surface. NOTE it is exactly the SAME WEIGHT!

QUOTE (meBigGuy+Nov 5 2007, 09:52 AM)
If we could take all the neutrons out, then it would be weightless and .... Oh, ....  nevermind.
and the remnant Proton's energy, since like charges repel, would EXPLODE MASSIVELY
Grumpy
Mr. Robin Parsons

You just don't seem to get anything. Even if the SE weighted a THOUSAND times as much as it will need to, it still would not make a difference to the movement of the Earth. By your logic, a flea on the left side of an elephant would cause the elephant to fall over.

Grumpy
Mr. Robin Parsons
QUOTE (Grumpy+Nov 5 2007, 12:11 PM)
You just don't seem to get anything. Even if the SE weighted a THOUSAND times as much as it will need to, it still would not make a difference to the movement of the Earth. By your logic, a flea on the left side of an elephant would cause the elephant to fall over. Grumpy

So Grumpy in geostationary orbit the object that stays in perpetual orbit over one spot on the planets face does so according to the very same physics governing the space shuttle, ergo it is it's forward velocity that maintains it's position in space as that is the balance against gravities pull that still, at that point, tries to pull it down.

It is following the Curvature of Space according to it's gravitationally generated Profile*....

At 24,000 miles out (Plus 4,000 for the earth's radius) we find the need of maintaining a forwards velocity of 3665.19 Mph in order to remain in a geostationary position.....How to you propose maintaining that speed? as ANY drag (Tug upon the Earth) will slow it down and then the greater effective pull of gravity will drag it down even faster.....

*Look at the image "Lumpy Earth"
Grumpy
Mr. Robin Parsons

QUOTE

At 24,000 miles out (Plus 4,000 for the earth's radius) we find the need of maintaining a forwards velocity of 3665.19 Mph in order to remain in a geostationary position.....How to you propose maintaining that speed?

Geostationary orbit simply means a spacecraft remains stationary over one point on the equator. By balancing the inward and outward sections of the SE from that point the inward side can be let down to the Earths surface as the outward side is let out to balance it. As long as the center of gravity remains at geostationary height, what's the problem???

Grumpy
N O M
parsons, are you familar with the Titius Bode law?

This predicts the ratios of the orbits of the planets. It is largely due to the affect of Jupiter's gravity on the orbit of all other planets. It makes all the planetary orbis fairly stable. So stable, in fact, that the Earth's orbit remains stable even after the collision that created the moon.

Nothing we will ever put into orbit around the Earth will ever affect the orbit enough to make it unstable. Unless you think we could make Jupiter's orbit unstable too.
Sapo
QUOTE (N O M+Nov 5 2007, 05:42 PM)
parsons, are you familar with the Titius Bode law?

(The Parsons Thing) will probably tell us that his efforts in the (Canadian Court) have made it illegal.
Mr. Robin Parsons
QUOTE (Grumpy+Nov 5 2007, 06:36 PM)
Geostationary orbit simply means a spacecraft remains stationary over one point on the equator. By balancing the inward and outward sections of the SE from that point the inward side can be let down to the Earths surface as the outward side is let out to balance it. As long as the center of gravity remains at geostationary height, what's the problem???

As you let it down gravity gains a purchase on it and pulls, it will keep pulling upon it increasing in strength (Weighting) as it descends, and there is no counter-force exerted to counterbalance that as the wire that goes out from it at Geosynch is still subjected to gravity and it too is being pulled down...unless you can maintain the orbital speed THEN with a weight at the end, tension it...then you tug on the Earth itself, do that long enough and it will affect it and it's twenty four thousand year cyclical pathway that corresponds to four different Polar stars - over that time.

N O M you've no proof....
Sapo
QUOTE (Mr. Robin Parsons+Nov 5 2007, 08:14 PM)
..., do that long enough and it will affect it and it's twenty four thousand year cyclical pathway that corresponds to four different Polar stars - over that time.

N O M you've no proof....

Except the accepted science that you blithely deny. I have no 'proof' that you are a mοrοn, except the content of your posts. If you think that hanging a minuscule weight from the planet is going to seriously affect the Milankovich cycles, you should try sleeping in a warmer alley...
Mr. Robin Parsons
QUOTE (Sapo+Nov 5 2007, 09:22 PM)
Except the accepted science that you blithely deny. I have no 'proof' that you are a mοrοn, except the content of your posts. If you think that hanging a minuscule weight from the planet is going to seriously affect the Milankovich cycles, you should try sleeping in a warmer alley...

(I) Sleep in an Emergency shelter.

Affecting those cycles takes very little - so long as it persists enough over a small amount of time - as the planets pathway could easily take a small affectation and disproportionately expand upon it - over time - to the point that way more changes then you seem to expect
Sapo
QUOTE (Mr. Robin Parsons+Nov 5 2007, 09:09 PM)
(I) Sleep in an Emergency shelter.

I suspect that (you) aren't welcome for more than one night, too, if (you) act like this in public.
QUOTE
Affecting those cycles takes very little - so long as it persists enough over a small amount of time - as the planets pathway could easily take a small affectation and disproportionately expand upon it - over time - to the point that way more changes then you seem to expect

The magnitude of your narcissism is becoming apparent, as you 'easily take a small affectation and disproportionately expand upon it'.

Dolt.
N O M
QUOTE (Mr. Robin Parsons+Nov 6 2007, 02:09 PM)
Affecting those cycles takes very little - so long as it persists enough over a small amount of time - as the planets pathway could easily take a small affectation and disproportionately expand upon it - over time - to the point that way more changes then you seem to expect

So you didn't look at the Titius Bode law link?

The Earth formed in a stable orbit, as defined by the Titius Bode law. A rogue planet, probably fired inward by Jupiter (and obviously not in a stable orbit), hit the Earth with enough force to split it into the earth-Moon pair. It's still in the same stable orbit. Proof.
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