Talk:Space elevator
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TAPER CALCULATION WRONG
i believe the taper calculation between earth and geo is wrong. it is exp [p/s * (4.8*10^7]] this agrees with the taper calculation on Pearsons paper
| Contents |
POV, but don't ask me...
Hmm... looking over the talk page, I can see this is a somewhat controversial article, so quite frankly, I'd rather not get involved, but an anon just added some content that reads like someone's personal POV essay rather than like encyclopedic information, ie: unqualified statements about government motivations, etc.: http://en.wikipedia.org/w/wiki.phtml?title=Space_elevator&curid=29192&diff=0&oldid=0 func(talk) 21:04, 27 Nov 2004 (UTC)
- (Above lgoes to latest edit, but the datestamp and context indicates he is referring to the anon edit of Nov 25: http://en.wikipedia.org/w/index.php?title=Space_elevator&diff=8027958&oldid=7847322 )
- I agree with Func that the anon edit of Nov 25 is POV. It is hardly settled what the roles of governmental, inter-governmental, and private organizations should/would/will be. This is perfunctorily acknowledged a few times, yet there is a clear POV here. In some cases this may have been entirely unintended due to basic assumptions made by anon. Examples (admittedly cherry-picked):
- made possible because of the savings made by governments in accessing space - many industries and organizations stand to benefit, and only mentioning one implies an special importance. It may well work out that way, but it oughtn't be assumed. Is this even relevant?
- At present, only governments are able to spend that sort of money in the space industry - I don't think this can or should be stated as fact. Seems like the Wal-Mart heirs could scrape together US$5B between them, not to mention Gates, Buffett, Allen, M. Dell....I have *zero* interest in resuming the economics debate here, but can we take it as given that all sorts of industries, organizations, and individuals would stand to profit, even indirectly, from low-cost space delivery? This greatly enlarges the pool of potential investors beyond the Forbes list.
- from a political standpoint there is a case to be made that the Space Elevator should be an international effort like the International Space Station with the inevitable rules for use and access - Likewise there is a case to be made that long-term international efforts inevitably fail to accomplish anything (ISS indeed!). While my own POV is no more appropriate here than anon's, it is certainly not less so.
- From the same edit, the mentions of benefits to health care, education, etc. probably should be de-POV'd and moved to the general overview paragraph, and mentioned again in the Economics section. It is also unclear to a layman what is meant. We know why education might be improved or medicines might be cheaper, but this article isn't just for us.
- Other proposed edits to Politics section:
- The frequent references to the US military verges on POV, as those statements are really applicable to any space power -- ongoing US space superiority is hardly guaranteed even as things stand today. One might just as well theorize that the US would *back* a space elevator in order to maintain supremacy. I think the military issue should be stated in as general a manner as is possible.
- The issue of ownership and political control is not new here. Weapons technology, steam power, nuclear power, etc., it's been dealt with many times before, and history shows that once a new technology becomes viable it will be seized by anyone who is sufficiently determined. That point is even made later in the politics section. I consider this an internal contradiction -- perhaps a result of the reorganization(s)?
- There is the notion that opening space to exploration would erode the relevance of national borders anyway. Indeed this is implicit in all of these political issues. Is discussion of a free-market path appropriate here? Or speculation about each space-elevator becoming a wholly separate political entitity? (Remember the Spacing Guild from Dune?) As it stands this is a rather technical article, such speculation may be out of character -- OTOH this *is* the politics section, and such is the nature of the beast. I think the possibilities at least deserve mention.
- I have no wish to dominate with my own POV, just seeking balance. I think some of these changes are clearly justifiable, yet with this many I figure I'll bring it up for discussion first.
- --EllisWyatt 00:58, 20 Jan 2005 (UTC)
- Don't forget that POV is *not* incorrect in Wikipedia (see NPOV). If you have a contrary view and you can back it up with references add your own POV. - Wolfkeeper
To-do
- I have restructured the article a bit. I felt it was awkward before, but there are still some problems.
- Partially as a result of my structural edit mentioned above, the text needs to be improved (e.g. by adding an overview paragraph at the beginning of each section) so the sections fit together better
- In particular, the article seriously needs a good introduction to the design and physics of a space elevator before going into details about the components
- The article is too large, so some text should be moved to specialized articles (as was done with the economics section). This might require additional restructuring to the article. Ideas?
- External links must be separated from references, and all external links need descriptions
- A few diagrams would be nice.
- Fredrik | talk 09:46, 15 Dec 2004 (UTC)
Interesting, by the way: apparently my structural edit got broken into three (check the page history). There must have been some issues with the database, as saving did take a while and I got an error message while previewing. The end result seems correct though. Fredrik | talk 09:50, 15 Dec 2004 (UTC)
I have added one diagram. Did I get the details right? Fredrik | talk 12:31, 15 Dec 2004 (UTC)
- Very nice; looks good. I would be tempted to poke around on various NASA sites looking for a view of Earth from the pole to put in, but that's hardly necessary. Is the diagram to scale? Even the longest cable proposals are only about 20 earth radii long; it might be nice to emphasize the size of the project. --Andrew
Is NIAC corruption relevant?
Wolfkeeper moved some comments about NIAC from the article body into references. While this may be a good decision, I am not fully comfortable with the article's current position towards Bradley. While I intend in no way to question his qualifications, he is currently called "a leading authority on the space elevator concept", which may not be the most accurate statement. Bolonkin gives a detailed description of corruption in NIAC [1] (http://english.pravda.ru/mailbox/22/98/396/14417_NASA.html) and also strongly criticises the report by Edwards and Cassanova, saying that "The 42-page report [which costed taxpayers almost 1 million dollars], half of which is mere illustrations, represents a mere explanation of the idea of the space elevator intended for elementary school pupils." [2] (http://english.pravda.ru/world/20/91/368/14685_.html). I think that this information should be reflected in the article in some form, and our praise for Edwards should be somewhat limited. Paranoid 18:25, 17 Jan 2005 (UTC)
- Well, I think he has done more than this:
- he suggested that it might be built in the near future, as in 10-15 rather 50 years
- he suggested the technique of installing a seed elevator and building it up from the ground
- he suggested ribbon construction techniques, again I've seen that nowhere else
- Still, the beanstalk idea has been around for quite a while, and has been worked on by plenty of people. If you have any information to *add* to the article, go ahead. But try not to delete anything as that violates wikipedia's [NPOV].
- -Wolfkeeper
- First, I don't see why deleting something unneeded would violate NPOV policy. Second, I haven't actually deleted anything from the article, I *added* information. Third, I am not saying Edwards is a fraud. For all I know he might be a genuine space elevator specialist and enthusiast, who has to work within the system, even if that means accepting money on questionable terms.
- Even *if* the guy awarding the prize is corrupt, there's absolutely no evidence in the article to suggest that Edwards is.
- May be it's so. Still, the fact is that the report for which he got a grant from NIAC was criticised for not being very substantial and not worthy of 1 million.
- I disagree. A whole bunch of people now actually think that the Space Elevator can be built in the near future, rather than the far future. And he has come up with a plausible technique and design for doing it. Is that worth $1 million? Who's to say it isn't? He has raised interest in carbon nanotubes, he has very probably created work for material scientists across the globe. There are now yearly conferences on Space Elevators, people are doing conceptual work on what they would look like etc. etc. It seems to me he has created something of value, something worth more than $1 million to all the research scientists.
- It was also asserted that this grant proposal was not approved by a real review panel.
- I think that that would be much more appropriate under the NIAC entry. Why don't you create the NIAC entry and include it?
- It may very well be possible that Edwards is just an opportunist.
- My take on it is that NIAC is intended to pay people with interesting ideas money so that they can push the boundary and see where it leads. It's clear that the ideas will mostly *not* pan out. I've worked on R&D. It's a very difficult thing to work on- the difference between an idea that cannot pan out, and can pan out with some careful thinking is very unpredictable. That's partly why the NIAC award process is 2 part.
- I also think that of the two stages, Edwards first stage was worth more than he was paid, the second stage he'd run out of ideas. Overall, over the two stages, I don't see that he didn't deserve the money, on the contrary, I think he did.
- The NPOV policy suggests that we include Bolonkin's view. I am just trying to determine what would be the best way to do this. Perhaps I didn't state t hat clearly as a question in my previous comment, so I am doing it now. How we should include this information (or why we shouldn't)? Paranoid 09:07, 18 Jan 2005 (UTC)
- IMO Criticisms of NIAC should go on the NIAC page. Criticisms of whether Edwards deserved to get that much money or not; it's probably best to only mention in Space Elevator; this piece is about Space Elevators, not Brad Edwards. I do think though that R&D funding is the kind of thing that is extremely easy to criticise and very, very difficult to do well. Personally, I think that the Space Elevator concept *should* have won the awards.
- Incidentally, I think that the Space Elevator page could do with much more history, particularly including Konstantin Tsiolkovsky, Clark etc. etc.
- I agree that the report would be worth the $1mln even if it turned out both Edwards and Cassanova were frauds and the report was plagiarised from a geocities webpage. The publicity for the space elevator idea is worth the money NIAC paid for it. However, the fact that Edwards was paid 600 thousand for the report doesn't necessarily mean he is a good specialist in this area (especially if the money is awarded in a very questionable way). So why do we call him the "leading authority"? The "most financed scientist"? Sure. But to be a leading authority he needs something more (again, I have nothing against the guy and he may end up being the LA). In the very least it is not justified to call him that. Paranoid 18:42, 18 Jan 2005 (UTC)
some additional ideas
The center of mass of the space elevator must be higher than the geosynchronous orbit, to exploit Earth's angular momentum when the climber goes up. If its center of mass is exactly at the geosynchronous orbit, it becomes unstable as soon as the climber goes up because of Coriolis force.
In addition, it is possible to build a space elevator away from the equator, even near the north or south pole. It is good because we can build it in politically and economically better places such as in the U.S. and we can avoid satellites on the equatorial plane. The weather will be worse than that on the equator, though.
___|___
/ | \
/ | \______
| | | \---------------O counterweight
| | |
| | |
\ | /
\___|___/
|
axis
(Sorry for the poor figure.) The space elevator is stable if it circulates Earth geosynchronously at an orbit where the three forces of centrifugal force, the cable tension, and Earth's gravity cancel. The latter two forces don't have to be perpendicular to the axis, as far as their combined force is perpendicular. This orbit is away from the equatorial plane. - TAKASUGI Shinji 06:56, 9 Mar 2005 (UTC)
Is the "center of mass" really the critical feature? I agree in that it must lie "higher" than geosynchronical orbit, but this results automatically since the crucial concept seems to be the fact that the *sum* of centrifugal force and earth's gravity is zero in any point of the cable. Or am I wrong with this notion? Hochnebel 14:08, 11 Mar 2005 (UTC+1)
if I've understood you correctly... the whole cable is *necessarily* under slightly more tension than the theoretical minimum necessary, so the sums don't quite cancel. And that's because the center of mass is above geo. And if it wasn't, then elevator would lean slightly, pushing the CofM below GEO and then it would actually fall right down to the ground.
- Well, center of gravity, technically. And the altitude of geostationary orbit is the only point along the cable where (F_c + F_g) = 0. Otherwise, you wouldn't need the incredibly strong cable to keep things from falling or flying away. The CG of the cable has to be higher than GEO or you've got no payload capacity; the system needs enough buoyancy to support its maximum load, plus a safety factor.
- —wwoods 16:59, 11 Mar 2005 (UTC)
- No. The center of mass has to be above GEO for the elevator to be stable. Atleast, I'm fairly sure, and see Bertrand Gassende's page at http://www.mit.edu/people/gassend/spaceelevator/center-of-mass/ says the same. The center of gravity can actually be below GEO due to the non linear gravity that the earth and the rotational non-inertial frame of the Earth. WolfKeeper
- I wanted to say the center of (gravity + centrifugal force).
- The figure below shows a space elevator on the equator seen from the north. Earth's surface is moving eastward.
O counterweight
|
|
|
|
Climber O→ Coriolis force
(goes up)|
|
---------+-----------
East ← West
Earth
- When the climber goes upward, the westward Coriolis force is produced, which is the same as the force necessary to accelerate the climber's speed eastward to keep the same angular speed. Remember each point of the space elevator has different speed, though they have the same angular speed.
- Now, because of the Coriolis force, the whole elevator above the climber is dragged down because of the cable tension.
O counterweight
|↓(dragged down by tension)
|
|
|
Climber O→ Coriolis force
(goes up) /
/
---------+-----------
East ← West
Earth
- Because of this, the center of (gravity + centrifugal force) must be higher than the geosynchronous orbit even when the heaviest load is on the climber.
- The westward shift of the space elevator is automatically recovered because the centrifugal force is stronger than the gravity. See the figure above upside down and treat the elevator like a pendulum. Thus we don't have to accelerate the climber eastward. - TAKASUGI Shinji 03:20, 13 Mar 2005 (UTC)
space elevator humor
Should we have a "space elevator humor" section in the article ?
- I wouldn't have thought so, it doesn't seem very encyclopedia-like Wolfkeeper 00:35, 6 Apr 2005 (UTC)
impact of falling cable?
Section 3.5 reads "the devastation created by thousands of tons of cable striking across hundreds of miles at terminal velocity could have unimaginable effects". Posts on slashdot.org, however, suggest that there might be very little devastation. To quote from this post (http://science.slashdot.org/comments.pl?sid=145575&cid=12190791):
The surviving fragments of an orbital tether would not have the requisite mass to produce the sort of wave disturbances you postulate. Actually, from most accounts, the worst health hazard resulting from a broken orbital tether would be small fragments of nanotube floating about in the atmosphere, eventually drifting to ground level and getting lodged in the lungs (as it turns out, carbon nanotubes are about the same size as asbestos fibers...perfect for getting lodged in the lungs).
Also, to quote from this post (http://science.slashdot.org/comments.pl?sid=145575&cid=12190866):
That's why you don't build it as a cable. You build it as a ribbon, with lots of surface area. If the ribbon snaps, portions high up in the atmosphere will burn up upon reentry. The portions of the cable that don't burn will flutter to the ground - think tickertape parades.
I don't know enough about the issue to make any comments, myself, but the above seems to suggest that a bit more justificiation as to why (or why not) a falling cable would have a devastating impact. TerraFrost 19:59, 13 Apr 2005 (UTC)
- You're right, that section greatly overstates the effects (as well as using dubiously scary statements to suggest the effects can't even be predicted). Space elevator#In the event of failure already discusses what sort of impact a break in the elevator would have, so I'm going to trim those bits out of the sabotage section. If someone wishes to dispute it then that's where the text should be disputed. Bryan 01:00, 14 Apr 2005 (UTC)
- The falling cable would have a limited (even if high) speed at falling, so there would be time for early warning of affected areas.--Deelkar (talk) 19:35, 30 Apr 2005 (UTC)
Are there any proposed solutions to the failure cascade problem?
The "Meteoroids and micrometeorites" section of the article describes how minor damage would be expected to cause cascading fiber breakage and destruction of the cable. Has this been addressed in the literature, and is there a proposed solution to the problem?
Well, Freeman Dyson's view on the problem is that space elevators will not work because of this problem: "but I am willing to be persuaded wrong". If a man who showed mathematically that it might be possible to use nuclear bombs as a propulsion device to launch from the surface of the Earth thinks it looks tough, IMO it may be a difficult problem to solve. WolfKeeper 00:47, 2005 May 3 (UTC)
Interesting. Can you supply a citation for this?
- "I am on record in saying that it won't work, but I love to be proven wrong," Dyson said, noting that the elastic energy would have to be equal to the chemical energy required to send a rocket to space. "If it tears in one place, it is likely to be a disaster."
An edit and its motivation: In the summary, the sentence
- A considerable number of other novel engineering problems would also have to be solved to make a space elevator practical.
has been changed and expanded to:
- A range of other novel engineering problems must also be solved to make a space elevator practical, but most have proposed solutions. However, one critical problem, cascading fiber breakage, apparently has no proposed solution (see below, "Meteoroids and micrometeorites").
The change to the first sentence tightens it up and then notes the existence of potential solutions to a wide range of problems. The added sentence notes what is, to the best of my knowledge, a unique issue in that it is potentially fatal and as yet unaddressed, with no proposed solution. I believe that this issue is important to evaluating the space elevator proposal, and should be highlighted in part to stimulate efforts to address it. Note that Wolfkeeper (above) found that Freeman Dyson sees this as a critical issue.
I am sure that this change will be unpopular because it highlights a serious problem in a popular idea. Potential criticisms might be:
- 1) That the problem does not exist (but it is easy to see that it is real).
- You don't know that. It critically depends on the failure modes of a material that doesn't even exist yet. The spring energy in the cable is similar to the energy in an explosive. As the cable contracts it may very well vaporise. It is very unclear whether vapour would damage the cable; and anyway it may well be possible to introduce 'fire breaks' at multikilometer distances or something to stop the problem propogating. Don't forget that the cable can be shaped like a hoytether, the entire cable needn't fail due to one impact.WolfKeeper
- The speed of motion of a broken fiber end -- very roughly 1,000 m/s -- isn't a matter of speculation, but of simple physics (conservation of energy and momentum). Unlike the situation in an explosive, the energy can't appear as heat without a further step (stopping the motion of the fiber). If the fiber were somehow braked to a stop, the resulting thermal energy would be enough to raise its temperature by (very roughly) 1,000 deg C. (This is a consequence of conservation of energy and of the heat capacity of graphitic carbon.) This is a nasty temperature, but far short of what is required to vaporize carbon.
- It doesn't even have to stop to get hot. Merely contracting the cable makes it hot. WolfKeeper
- There is a weak effect of this sort, but the increase in temperature is about the same as the decrease caused by stretching, which is very small (it depends on the anharmonicity of the interatomic potentials, which is small in the working-stress range. By the way, a rubber band actually cools when it contracts, because its elasticity comes primarily from changes in the entropy of the polymer chains. It's fun to try it: take a rubber band, stretch it hard, and touch it to your lip. Detension it, touch again. Repeat a few times. You should notice a substantial temperature swing. (By the way, I do know what I'm talking about on this stuff, which may have to do with a graduate degree in aerospace and considerable background in physics.)
- By saying that the problem exists, I mean that (unlike, say, the idea that alien brainwaves will break the cable) this is a problem requiring explicit consideration. This means applying basic physics to proposed designs to get some idea of what happens. Until this is done and a plausible case is made that 1,000 m/s debris can be dealt with, the problem remains. I am shocked that I can find no discussion of this issue. The absence of discussion was noted in the entry last January, and no one has reported finding a discussion since.
- Maybe a hoytether structure with 'fire breaks' can do the job. I wouldn't be greatly surprised either way. But until someone looks at this very basic question, it's hard to take space elevator designs seriously.
- Is there any other basic, potentialy fatal problem that is known, yet hasn't had any visible analysis at all? If so, I'd prefer that it, too, be separated out from the problems that already seem to have good answers. Open questions need to be highlighted, not hidden.
- 2) That the problem has a known, in-principle solution (which it may, at some point).
- 3) That the problem -- which questions the proposal as a whole -- should be buried with others that do not.
Protection from meteoric debris
Perhaps a shield of some sort could be constructed after the space elevator becomes load bearing for cargo. Something shaped like an open, windblown umbrella, with the handle being a small diameter shield around the cable ?? meters, and the larger lower section designed to deflect debris coming in from a higher orbit at an angle. These shields would probably have to have manuevering systems built in to move with the tether, which would add a refueling cost to the tether, plus increased maintenance to ensure the tether shield would be reliable. We could use the multilayer shielding ideas that have been used for the space station, with improvements of course. Just a thought...
The Stub Maker - Zotel
The Van Allen Belt's Impact on the space elevator
I moved this material back from Van Allen Radiation Belt (it was moved from here to there, but really is too spcific for that article). However, there is already a section on radiation hazards in the article. So I'm leaving this here.RJFJR 02:45, May 11, 2005 (UTC)
When the Apollo astronauts travelled to the moon the astronauts received about 1% of a lethal dose in the few hours they were crossing these regions of space. By way of contrast a space elevator will spend anywhere from hours to weeks in these regions, and if the final destination is geosynchronous orbit, the length of stay could be indefinite. Without shielding, this could pose a serious risk to passengers.
As with nuclear power, the problem is that the necessary radiation shielding is very heavy - much heavier than the people it protects; having to lift the passengers as well as the shielding may increase the ticket price many times over the equivalent quantity of freight (since most freight wouldn't be affected by radiation issues and doesn't require shielding).
The radiation belts are based on Earth's magnetic field, which is tilted at about 11 degrees from its rotational axis. They are further distorted by the solar wind, giving them a teardrop shape. Due to this, the elevator will encounter varying intensities of radiation; especially concerning is the inner belt.
One proposal for two way elevator systems to deal with the outer belt is to have extra shielding "in-place" along the cable that is carried up by a climbing elevator, and carried back down by a descending elevator to meet the next elevator carrying passengers up. While this adds constant weight to the elevator (as if a "permanent payload"), it adds the weight to the elevator where the cable is thickest and most able to tolerate extra payload. The "weak point" of the elevator is where it meets the Earth, and shielding is not needed there.
Another type of shielding is so-called "active" shielding. One such type involves electromagnetic fields to deflect low-energy radiation. Another type of active shielding is the Multilayer High Temperature Superconductor Protection System, which involves using high-temperature superconducting materials to produce strong magnetic fields for deflection. [3] (http://www.seds.org/pub/info/mars/RadProt.doc). In theory, anything that produces a strong magnetic field could be used to deflect the radiation, but the strength of the magnetic field produced given the weight of the materials required can be a limiting factor. Active shielding, in its current designs, is very effective at shielding from protons of energies up to 200MeV, but is largely ineffective against galactic cosmic radiation (GCR) [4] (http://www.physicamedica.com/VOLXVII_S1/17-TOWNSEND.pdf). As the dangerous inner Van Allen belt consists mostly of protons from energies between 10 and 100 MeV, and particles in the outer van allen belts are lower energy (around 1 MeV) [[5] (http://www-istp.gsfc.nasa.gov/Education/wradbelt.html)], active shielding is a realistic option for the transit up to GEO. However, since it is ineffective against GCR, long-term human stays at GEO would require physical shielding in the structure they are to stay at.
There is also a proposal by the late Bob Forward called HiVolt which may be a way to drain at least parts of the Van Allen belts to 1% of their natural level within a year.
Mechanical climbers on the space elevator could draw energy from the belts as they travel through it. This would provide some power to the climber, and, after several thousand climbs, the belts would be reduced to a tiny fraction of their original intensity.
- Where did you get this bit from? It sounds prima facie implausible, and even if it worked (I doubt it), where does that get you if the power is gone after a few thousand climbs?
- So what gives? WolfKeeper
- I got this from the article on the van Allen Radiation belt. I just moved the section here. (I suppose we could go through that article's edit history and look for who added this material). I beleive this material was originally here in some form (it was probably edited while it was at that article). Myself, I'm kind of suspicious of the HiVOLT idea, but I'm not quite qualified to say it wouldn't work.RJFJR 01:24, May 12, 2005 (UTC)
Cable Taper Calculations, necessary?
This article is causing a length warning. Looking through it the Cable Taper section looks expendable. I considered moving it to its own page, but I didn't think it would have enough context to make sense. Or we could just delete the whole thing, but I like the 4 points at the end. Anyone have a good idea about this section? RJFJR 02:45, May 11, 2005 (UTC)
- We could move it to a new article called "Space Elevator Physics" -- Klafubra 13:09, 17 May 2005 (UTC)
Space elevators as an energy source?
Could a space elevator be an energy source by using the thermal/electrical differential between Earth's surface and cold space/the ionosphere? Ultramarine 19:54, 12 May 2005 (UTC)
Space elevator or Beanstalk
user:Wolfkeeper moved most of the article to Beanstalk, which was previously a redirect here. I changed both back. I didn't care if he moved all the article there, I objected to moving part of the article.
I am of the opinion we should pick one name and have the other redirect to it. I don't care which is which I just don't want part of the text at one and part at the other. They look like synonyms to me so have one article.
- They aren't. That's the whole point.
- A beanstalk is a cable from geo, whereas a space elevator is anything that is connected to a planetary body that reaches space. That's *not* the same thing. Designs exist for very tall, spindly towers that reach 100km for example, that's space. Or there's a design for a rotating orbital ring that has spokes hanging down off bearings. Or the space fountain idea. The point is that they are *not* the same.
- Just like a lion is a cat, but a cat is not a lion, a beanstalk is a space elevator, but a space elevator is not a beanstalk. WolfKeeper
(That is different than the proposal to have a seperate article on the physics of the space elevator, which would result in a more focused article and one that meets the length recommendation. I like that idea.) RJFJR 15:56, May 20, 2005 (UTC)
(If it gets moved then the talk page should go with it. RJFJR 16:02, May 20, 2005 (UTC))
- I disagree with moving the article. Your point seems to be that a space elevator is 'any method of lifting cargo into orbit', which is rediculous.
- Yes, that would be. Which is why it wasn't my point. My point is that *a* correct name for a geosynchronous orbital tether is 'space elevator', and then listed a number of other concepts that are also space elevators.
- The space elevator concept refers specifically to an elevator, with the cable, and the elevator-cabin, and the moving up and down.
- But all the tall structures have that. Isn't that the whole point, that there is an elevator, a cable, a car, and it goes to space? The geosynchronous orbital tether is just one example.
- A beanstalk, to me, is what you get when you plant beans. -- Ec5618 17:05, May 20, 2005 (UTC)
- Yessss. What a shame that the english language doesn't permit more than one definition of a word. Oh! Wait! WolfKeeper
I think Wikipedia must be descriptive of terminology use, not prescriptive. I haven't done a rigorous survey, but it seems to me that when most people these days talk about beanstalks, they use the term "space elevator" to describe it - all ten of the top Google results for "space elevator" are focused on the cable kind (though one's Wikipedia itself so that doesn't really count :). Furthermore, "space elevator" gets 2.3 million hits on Google compared to only half a million for "beanstalk", so I think we should probably go with that. Bryan 23:36, 20 May 2005 (UTC)
- Heh heh. I already did much the same thing; I wasn't exactly planning on going through the wikipedia removing 'Space Elevator' and putting 'beanstalk' though. WolfKeeper
- Actually, I was only arguing about where to put it in the wikipedia, not trying to redefine anything, I certainly agree that most people do use 'Space Elevator' for geosynchronous orbital tethers and I agree that they are Space Elevators. But there is a structural problem here because the article reads like a Space Elevator is only that; and it looks like half the contributors think that too. Heck, maybe it is, there's nothing that says that a Space Elevator is an elevator that goes to space, if every word or phrase meant exactly what it sounded like we wouldn't need dictionaries, but I'm not aware of any firm definition of it anywhere. WolfKeeper
- OTOH, a beanstalk is unequivocally a synchronous orbital tether, so putting it there is correct, but some people evidently absolutely loathe the term. Space Elevator has less precise connotations, but is somewhat more generic and popular. WolfKeeper
- We could consider moving the bulk of the article to 'Synchronous Orbital Tethers' but perhaps some people would hate that more than sticking it under beanstalk. WolfKeeper
- How about we leave it here, redirect everything to here and add a section to the intro about what redirects in and the subtle (or not so subtle) distinctions? (I did a google on "space elevator" beanstalk' figuring the pages would either tell me they were the same or different...it didn't work.
- I still claim that they aren't necessarily the same thing. Unless you believe that a space fountain isn't a space elevator. I considered that, but I decided that it was.
- But I did see one claim that trying to build a structure to orbit was impractical and hence the cable down from the top idea.) RJFJR 18:30, May 21, 2005 (UTC)
- What? This link you mean: http://umich-web0.everything2.com/index.pl?node_id=1334678 ? If so, yeah, I wrote that :-) Note that there's a distinction between *orbit* and *space*. They are NOT the same thing. Also note that everything2 isn't really an encyclopedia, it lacks precision, and you end up tailoring your articles to what would fly there.WolfKeeper
- The intro already has mention of both space fountains and tall compressive structures, with a link to the space fountain article. Are you thinking of making it more like a disambiguation section at the very top of the article instead? Bryan 18:45, 21 May 2005 (UTC)