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Groups > sci.physics > #690118 > unrolled thread
| Started by | Doc O'Leary <droleary@2017usenet1.subsume.com> |
|---|---|
| First post | 2018-06-11 22:18 +0000 |
| Last post | 2018-06-14 04:47 -0400 |
| Articles | 20 on this page of 84 — 12 participants |
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Re: Towards routine, reusable space launch. Doc O'Leary <droleary@2017usenet1.subsume.com> - 2018-06-11 22:18 +0000
Re: Towards routine, reusable space launch. Fred J. McCall <fjmccall@gmail.com> - 2018-06-11 20:52 -0700
Re: Towards routine, reusable space launch. Jeff Findley <jfindley@cinci.nospam.rr.com> - 2018-06-12 06:34 -0400
Re: Towards routine, reusable space launch. Doc O'Leary <droleary@2017usenet1.subsume.com> - 2018-06-12 14:36 +0000
Re: Towards routine, reusable space launch. Fred J. McCall <fjmccall@gmail.com> - 2018-06-12 14:29 -0700
Re: Towards routine, reusable space launch. Jeff Findley <jfindley@cinci.nospam.rr.com> - 2018-06-12 19:00 -0400
Re: Towards routine, reusable space launch. JF Mezei <jfmezei.spamnot@vaxination.ca> - 2018-06-13 02:15 -0400
Re: Towards routine, reusable space launch. Fred J. McCall <fjmccall@gmail.com> - 2018-06-13 01:27 -0700
Re: Towards routine, reusable space launch. Jeff Findley <jfindley@cinci.nospam.rr.com> - 2018-06-13 06:46 -0400
Re: Towards routine, reusable space launch. JF Mezei <jfmezei.spamnot@vaxination.ca> - 2018-06-13 16:28 -0400
Re: Towards routine, reusable space launch. Fred J. McCall <fjmccall@gmail.com> - 2018-06-13 14:38 -0700
Re: Towards routine, reusable space launch. Jeff Findley <jfindley@cinci.nospam.rr.com> - 2018-06-14 05:22 -0400
Re: Towards routine, reusable space launch. JF Mezei <jfmezei.spamnot@vaxination.ca> - 2018-06-14 15:44 -0400
Re: Towards routine, reusable space launch. Jeff Findley <jfindley@cinci.nospam.rr.com> - 2018-06-15 07:52 -0400
Re: Towards routine, reusable space launch. JF Mezei <jfmezei.spamnot@vaxination.ca> - 2018-06-15 21:33 -0400
Re: Towards routine, reusable space launch. Jeff Findley <jfindley@cinci.nospam.rr.com> - 2018-06-16 10:38 -0400
Re: Towards routine, reusable space launch. JF Mezei <jfmezei.spamnot@vaxination.ca> - 2018-06-16 17:51 -0400
Re: Towards routine, reusable space launch. Fred J. McCall <fjmccall@gmail.com> - 2018-06-17 02:16 -0700
Re: Towards routine, reusable space launch. JF Mezei <jfmezei.spamnot@vaxination.ca> - 2018-06-17 15:49 -0400
Re: Towards routine, reusable space launch. Jeff Findley <jfindley@cinci.nospam.rr.com> - 2018-06-17 16:52 -0400
Re: Towards routine, reusable space launch. JF Mezei <jfmezei.spamnot@vaxination.ca> - 2018-06-18 02:44 -0400
Re: Towards routine, reusable space launch. Fred J. McCall <fjmccall@gmail.com> - 2018-06-18 00:05 -0700
Re: Towards routine, reusable space launch. JF Mezei <jfmezei.spamnot@vaxination.ca> - 2018-06-18 14:27 -0400
Re: Towards routine, reusable space launch. Fred J. McCall <fjmccall@gmail.com> - 2018-06-18 19:39 -0700
Re: Towards routine, reusable space launch. Fred J. McCall <fjmccall@gmail.com> - 2018-06-17 18:26 -0700
Re: Towards routine, reusable space launch. Doc O'Leary <droleary@2017usenet1.subsume.com> - 2018-06-13 12:57 +0000
Re: Towards routine, reusable space launch. Fred J. McCall <fjmccall@gmail.com> - 2018-06-13 14:35 -0700
Re: Towards routine, reusable space launch. JF Mezei <jfmezei.spamnot@vaxination.ca> - 2018-06-13 17:55 -0400
Re: Towards routine, reusable space launch. Fred J. McCall <fjmccall@gmail.com> - 2018-06-13 21:44 -0700
Re: Towards routine, reusable space launch. Doc O'Leary <droleary@2017usenet1.subsume.com> - 2018-06-14 22:02 +0000
Re: Towards routine, reusable space launch. Alain Fournier <alain245@videotron.ca> - 2018-06-13 19:39 -0400
Re: Towards routine, reusable space launch. Fred J. McCall <fjmccall@gmail.com> - 2018-06-13 21:53 -0700
Re: Towards routine, reusable space launch. Alain Fournier <alain245@videotron.ca> - 2018-06-14 19:46 -0400
Re: Towards routine, reusable space launch. Jeff Findley <jfindley@cinci.nospam.rr.com> - 2018-06-15 07:56 -0400
Re: Towards routine, reusable space launch. Alain Fournier <alain245@videotron.ca> - 2018-06-15 19:21 -0400
Re: Towards routine, reusable space launch. Sergio <invalid@invalid.com> - 2018-06-15 19:18 -0500
Re: Towards routine, reusable space launch. Alain Fournier <alain245@videotron.ca> - 2018-06-15 21:05 -0400
Re: Towards routine, reusable space launch. Jeff Findley <jfindley@cinci.nospam.rr.com> - 2018-06-16 10:06 -0400
Re: Towards routine, reusable space launch. Alain Fournier <alain245@videotron.ca> - 2018-06-16 13:21 -0400
Re: Towards routine, reusable space launch. Jeff Findley <jfindley@cinci.nospam.rr.com> - 2018-06-16 13:57 -0400
Re: Towards routine, reusable space launch. Alain Fournier <alain245@videotron.ca> - 2018-06-16 14:19 -0400
Re: Towards routine, reusable space launch. mvp@web1.calweb.com (Mike Van Pelt) - 2018-06-19 18:38 +0000
Re: Towards routine, reusable space launch. Greg Goss <gossg@gossg.org> - 2018-06-19 21:27 -0600
Re: Towards routine, reusable space launch. JF Mezei <jfmezei.spamnot@vaxination.ca> - 2018-06-15 22:13 -0400
Re: Towards routine, reusable space launch. Fred J. McCall <fjmccall@gmail.com> - 2018-06-15 20:34 -0700
Re: Towards routine, reusable space launch. Alain Fournier <alain245@videotron.ca> - 2018-06-16 09:54 -0400
Re: Towards routine, reusable space launch. Sergio <invalid@invalid.com> - 2018-06-18 13:45 -0500
Re: Towards routine, reusable space launch. Alain Fournier <alain245@videotron.ca> - 2018-06-18 21:06 -0400
Re: Towards routine, reusable space launch. Fred J. McCall <fjmccall@gmail.com> - 2018-06-18 20:00 -0700
Re: Towards routine, reusable space launch. Alain Fournier <alain245@videotron.ca> - 2018-06-19 19:45 -0400
Re: Towards routine, reusable space launch. JF Mezei <jfmezei.spamnot@vaxination.ca> - 2018-06-19 22:12 -0400
Re: Towards routine, reusable space launch. Alain Fournier <alain245@videotron.ca> - 2018-06-20 20:21 -0400
Re: Towards routine, reusable space launch. Fred J. McCall <fjmccall@gmail.com> - 2018-06-20 17:13 -0700
Re: Towards routine, reusable space launch. Alain Fournier <alain245@videotron.ca> - 2018-06-20 20:34 -0400
Re: Towards routine, reusable space launch. Jeff Findley <jfindley@cinci.nospam.rr.com> - 2018-06-21 06:26 -0400
Re: Towards routine, reusable space launch. Steve Carroll <frelwizzen@gmail.com> - 2018-06-21 03:48 -0700
Re: Towards routine, reusable space launch. JF Mezei <jfmezei.spamnot@vaxination.ca> - 2018-06-21 13:35 -0400
Re: Towards routine, reusable space launch. Alain Fournier <alain245@videotron.ca> - 2018-06-21 20:57 -0400
Re: Towards routine, reusable space launch. Sergio <invalid@invalid.com> - 2018-06-21 23:22 -0500
Re: Towards routine, reusable space launch. Jeff Findley <jfindley@cinci.nospam.rr.com> - 2018-06-22 07:18 -0400
Re: Towards routine, reusable space launch. JF Mezei <jfmezei.spamnot@vaxination.ca> - 2018-06-22 17:45 -0400
Re: Towards routine, reusable space launch. Alain Fournier <alain245@videotron.ca> - 2018-06-22 19:58 -0400
Re: Towards routine, reusable space launch. JF Mezei <jfmezei.spamnot@vaxination.ca> - 2018-06-23 03:39 -0400
Re: Towards routine, reusable space launch. Jeff Findley <jfindley@cinci.nospam.rr.com> - 2018-06-23 08:38 -0400
Re: Towards routine, reusable space launch. JF Mezei <jfmezei.spamnot@vaxination.ca> - 2018-06-23 17:18 -0400
Re: Towards routine, reusable space launch. Alain Fournier <alain245@videotron.ca> - 2018-06-23 09:58 -0400
Re: Towards routine, reusable space launch. Sergio <invalid@invalid.com> - 2018-06-24 00:53 -0500
Re: Towards routine, reusable space launch. Jeff Findley <jfindley@cinci.nospam.rr.com> - 2018-06-23 08:34 -0400
Re: Towards routine, reusable space launch. Sergio <invalid@invalid.com> - 2018-06-18 22:17 -0500
Re: Towards routine, reusable space launch. Fred J. McCall <fjmccall@gmail.com> - 2018-06-19 00:45 -0700
Re: Towards routine, reusable space launch. Sergio <invalid@invalid.com> - 2018-06-19 15:58 -0500
Re: Towards routine, reusable space launch. Fred J. McCall <fjmccall@gmail.com> - 2018-06-19 14:38 -0700
Re: Towards routine, reusable space launch. Sergio <invalid@invalid.com> - 2018-06-20 15:42 -0500
Re: Towards routine, reusable space launch. JF Mezei <jfmezei.spamnot@vaxination.ca> - 2018-06-20 16:58 -0400
Re: Towards routine, reusable space launch. Thomas Koenig <tkoenig@netcologne.de> - 2018-06-25 20:44 +0000
Re: Towards routine, reusable space launch. Fred J. McCall <fjmccall@gmail.com> - 2018-06-20 17:07 -0700
Re: Towards routine, reusable space launch. Sergio <invalid@invalid.com> - 2018-06-21 23:24 -0500
Re: Towards routine, reusable space launch. Fred J. McCall <fjmccall@gmail.com> - 2018-06-21 21:38 -0700
Re: Towards routine, reusable space launch. Greg Goss <gossg@gossg.org> - 2018-06-19 21:35 -0600
Re: Towards routine, reusable space launch. Thomas Koenig <tkoenig@netcologne.de> - 2018-06-19 17:01 +0000
Re: Towards routine, reusable space launch. Sergio <invalid@invalid.com> - 2018-06-21 22:39 -0500
Re: Towards routine, reusable space launch. "reber G=emc^2" <herbertglazier0@gmail.com> - 2018-06-14 15:39 -0700
Re: Towards routine, reusable space launch. "hanson" <hanson@quick.net> - 2018-06-14 15:53 -0700
Re: Towards routine, reusable space launch. Jeff Findley <jfindley@cinci.nospam.rr.com> - 2018-06-14 04:47 -0400
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| From | JF Mezei <jfmezei.spamnot@vaxination.ca> |
|---|---|
| Date | 2018-06-22 17:45 -0400 |
| Message-ID | <G5eXC.366112$bS4.257372@fx01.iad> |
| In reply to | #691542 |
On 2018-06-22 07:18, Jeff Findley wrote: > Because it's flexible, duh. Imagine that you took 10 meters of fishing > line with a weight at the bottom then cut it in the middle. Would it > stay straight as it fell? Try it! This does not consider/test the issue that the top of the cable is travelling at faster speed and as it is being pulled down, will accelerate further. If the top of the cable wants to travel faster than the bottom part of cable, a tension will exist which would not exist in your fishing line example, and that tension should keep the cable straight. > Why did the Tacoma Narrows Bridge break up due to *wind*? That cable would have to travel over 38,000km in vacuum before it got to atmpsphere. So the top of cable (assuming breal at geostationary altitude) wouldn't have wind gusts at resonnance frequency.
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| From | Alain Fournier <alain245@videotron.ca> |
|---|---|
| Date | 2018-06-22 19:58 -0400 |
| Message-ID | <pgk2fi$vhc$1@dont-email.me> |
| In reply to | #691591 |
On Jun/22/2018 à 5:45 PM, JF Mezei Wrote : > On 2018-06-22 07:18, Jeff Findley wrote: > >> Because it's flexible, duh. Imagine that you took 10 meters of fishing >> line with a weight at the bottom then cut it in the middle. Would it >> stay straight as it fell? Try it! > > > This does not consider/test the issue that the top of the cable is > travelling at faster speed and as it is being pulled down, will > accelerate further. If the top of the cable wants to travel faster than > the bottom part of cable, a tension will exist which would not exist in > your fishing line example, and that tension should keep the cable straight. That tension you talk about is caused by the centrifugal pseudo-force. In the fishing line example Jeff gave there is the gravitational force that should pull the line down. In both cases, when the fishing line or the elevator cable snaps the elasticity pulls back with more force than the gravity or centrifugal force. With the caveat that we don't know what material would be used for the hypothetical space elevator, so we don't know how elastic it would be. But I think it is a safe assumption that if such an elevator was to ever be built, the material would be sufficiently elastic for tens of thousands of kilo-meters of it to give a very strong pull back. Alain Fournier
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| From | JF Mezei <jfmezei.spamnot@vaxination.ca> |
|---|---|
| Date | 2018-06-23 03:39 -0400 |
| Message-ID | <3PmXC.238286$o43.191504@fx33.iad> |
| In reply to | #691608 |
On 2018-06-22 19:58, Alain Fournier wrote: > In both cases, when the fishing line or the elevator cable snaps the > elasticity pulls back with more force than the gravity or centrifugal > force. Centrifugal force is equal to gravity at genostationary orbit for this setup. below that, gravity is bigger so it pulls cable down. But what your argument does not consider is that the cable at geostationary is travelling at roughly 9370 km/h. But throughout the cable, all portions have the same radial speed (15° per hour, 360° per 24 hours). As the topmost portion of the cable is pulled down, its speed increases and it now has a radial speed greater than 15° per hour. The lower end will pull cable down (gravity) and resist beiong pulled forward (either because still anchored or being dragged on ground (resistance). The higher end will respond to being pulled down by increasing forward velocity, thus tugging on cable to move horizontally. Those two forces should keep cable fully extended and straight. It won't be snaking around. Any elasticity in the cable means that when the initial break at geostationaly happens, the elasticity will pull cable down more than just gravity. But that extra force will also result in the top most portion accelerating horizontally. So it isn't clear that as the tension is released, the cable would "snake".
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| From | Jeff Findley <jfindley@cinci.nospam.rr.com> |
|---|---|
| Date | 2018-06-23 08:38 -0400 |
| Message-ID | <MPG.3598094ba35cbe2d989ae1@news.eternal-september.org> |
| In reply to | #691634 |
In article <3PmXC.238286$o43.191504@fx33.iad>, jfmezei.spamnot@vaxination.ca says... > Any elasticity in the cable means that when the initial break at > geostationaly happens, the elasticity will pull cable down more than > just gravity. But that extra force will also result in the top most > portion accelerating horizontally. So it isn't clear that as the > tension is released, the cable would "snake" When a very long cable breaks, the end that broke starts accelerating towards the end that's still fixed. It's not going to stop moving when the tension is gone due to inertia (i.e. objects in motion tend to stay in motion unless acted upon by an external force). That cable is going to go into compression. Guess what happens to a cable that you put into compression? Again, look at the papers written on the subject of the dynamics of a broken space elevator. It's not going to stay straight! Jeff -- All opinions posted by me on Usenet News are mine, and mine alone. These posts do not reflect the opinions of my family, friends, employer, or any organization that I am a member of.
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| From | JF Mezei <jfmezei.spamnot@vaxination.ca> |
|---|---|
| Date | 2018-06-23 17:18 -0400 |
| Message-ID | <mOyXC.362009$DS3.159932@fx42.iad> |
| In reply to | #691642 |
On 2018-06-23 08:38, Jeff Findley wrote: > When a very long cable breaks, the end that broke starts accelerating > towards the end that's still fixed. It's not going to stop moving when > the tension is gone due to inertia The discussion was about a break at geostationary altitude. The video animation you linked to showed a lot of "free floating snaking" in space, not in atmosphere. because gravity at geostationary altitude is I think 0.22 m/s/s, and at ground it is 9.8, the ground portion will want to accelerate faster than the high portion. So there will be tension on wire pulling down. And as the cable is pulled down, the top part which was travelling at some 9600km/h (geostationary orbit speed) will accelerate as it is pulled down, which means it will have a force to pull the cable eastward. Hence, a force pulling the cable away from its anchor point on earth. With forces acting in both directions, the cable should want to be straight after the initial "snap" for all areas above atmosphere (no atmospheric drag). Initially, with the lower portions of cable also travelling at 1666km/h (speed of ground at equator) and with cable initially vertical, it would fall straight down. (and thus break up as it nears ground and tries to bend as a string does when you lower it to bunch up on ground at a single spot. But as the even advances, the higher portion's movement towards the east will cause cable to become diagonal and could fall linearly aroudn equator until the topmost portion of cable has lost enough altitude that acceleration towards east is no longer a big factor and then the rest of the cable (a few hundred km) would fall straight down. But that still leaves potentially over 20,000 km of cable dropping linearly over equator. (half of earth's circumference). Also, depending on how much tapering there is on cable, the mass at altitude would be greater than at ground, so the force to accelerate towards east will be greater as cable is pulled down.
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| From | Alain Fournier <alain245@videotron.ca> |
|---|---|
| Date | 2018-06-23 09:58 -0400 |
| Message-ID | <pgljn3$3km$1@dont-email.me> |
| In reply to | #691634 |
On Jun/23/2018 at 3:39 AM, JF Mezei wrote : > On 2018-06-22 19:58, Alain Fournier wrote: > >> In both cases, when the fishing line or the elevator cable snaps the >> elasticity pulls back with more force than the gravity or centrifugal >> force. > > Centrifugal force is equal to gravity at genostationary orbit for this > setup. below that, gravity is bigger so it pulls cable down. > > But what your argument does not consider is that the cable at > geostationary is travelling at roughly 9370 km/h. But throughout the > cable, all portions have the same radial speed (15° per hour, 360° per > 24 hours). > > As the topmost portion of the cable is pulled down, its speed increases > and it now has a radial speed greater than 15° per hour. > > > The lower end will pull cable down (gravity) and resist beiong pulled > forward (either because still anchored or being dragged on ground > (resistance). > > The higher end will respond to being pulled down by increasing forward > velocity, thus tugging on cable to move horizontally. Those two forces > should keep cable fully extended and straight. It won't be snaking around. > > Any elasticity in the cable means that when the initial break at > geostationaly happens, the elasticity will pull cable down more than > just gravity. But that extra force will also result in the top most > portion accelerating horizontally. So it isn't clear that as the > tension is released, the cable would "snake". You are just missing the end of you last sentence. It isn't clear that as the tension is released the cable would snake until you do simulations to see what happens. Alain Fournier
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| From | Sergio <invalid@invalid.com> |
|---|---|
| Date | 2018-06-24 00:53 -0500 |
| Message-ID | <pgnbkf$stn$1@gioia.aioe.org> |
| In reply to | #691634 |
On 6/23/2018 2:39 AM, JF Mezei wrote: > On 2018-06-22 19:58, Alain Fournier wrote: > >> In both cases, when the fishing line or the elevator cable snaps the >> elasticity pulls back with more force than the gravity or centrifugal >> force. > > Centrifugal force is equal to gravity at genostationary orbit for this > setup. below that, gravity is bigger so it pulls cable down. nope. The orbiting object just needs to orbit faster to stay at the same height above the earth, and it does not go down. > > But what your argument does not consider is that the cable at > geostationary is travelling at roughly 9370 km/h. But throughout the > cable, all portions have the same radial speed (15° per hour, 360° per > 24 hours). the cable will bend under these conditions if very long. as the top part is going too fast to be geostationary, and the bottom is going too slow to be geostationary for the cable to remain normal to the Earths surface. Short cable is ok, but not a 10,000 km one. > > As the topmost portion of the cable is pulled down, its speed increases > and it now has a radial speed greater than 15° per hour. > > > The lower end will pull cable down (gravity) and resist beiong pulled > forward (either because still anchored or being dragged on ground > (resistance). > > The higher end will respond to being pulled down by increasing forward > velocity, thus tugging on cable to move horizontally. Those two forces > should keep cable fully extended and straight. It won't be snaking around. > > Any elasticity in the cable means that when the initial break at > geostationaly happens, the elasticity will pull cable down more than > just gravity. But that extra force will also result in the top most > portion accelerating horizontally. So it isn't clear that as the > tension is released, the cable would "snake". > > >
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| From | Jeff Findley <jfindley@cinci.nospam.rr.com> |
|---|---|
| Date | 2018-06-23 08:34 -0400 |
| Message-ID | <MPG.3598084885aeaa05989ae0@news.eternal-september.org> |
| In reply to | #691591 |
In article <G5eXC.366112$bS4.257372@fx01.iad>, jfmezei.spamnot@vaxination.ca says... > > On 2018-06-22 07:18, Jeff Findley wrote: > > > Because it's flexible, duh. Imagine that you took 10 meters of fishing > > line with a weight at the bottom then cut it in the middle. Would it > > stay straight as it fell? Try it! > > > This does not consider/test the issue that the top of the cable is > travelling at faster speed and as it is being pulled down, will > accelerate further. If the top of the cable wants to travel faster than > the bottom part of cable, a tension will exist which would not exist in > your fishing line example, and that tension should keep the cable straight. Depends a lot on exactly where it breaks. Also the drag from the atmosphere of earth makes the dynamics a lot different than on a mostly airless planet like Mars. Look again at the simulations and research papers on this subject that are online. > > Why did the Tacoma Narrows Bridge break up due to *wind*? > > That cable would have to travel over 38,000km in vacuum before it got to > atmpsphere. So the top of cable (assuming breal at geostationary > altitude) wouldn't have wind gusts at resonnance frequency. That's not what I meant. I meant that you can't know these things intuitively. The example was a huge bridge made of concrete and steel that was destroyed by wind. That's not intuitive! You have to do the engineering analysis on these things. Again, look at the research that's already been done. Jeff -- All opinions posted by me on Usenet News are mine, and mine alone. These posts do not reflect the opinions of my family, friends, employer, or any organization that I am a member of.
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| From | Sergio <invalid@invalid.com> |
|---|---|
| Date | 2018-06-18 22:17 -0500 |
| Message-ID | <pg9sk3$13su$1@gioia.aioe.org> |
| In reply to | #691148 |
On 6/18/2018 8:06 PM, Alain Fournier wrote: > On Jun/18/2018 at 2:45 PM, Sergio wrote : >> On 6/16/2018 8:54 AM, Alain Fournier wrote: >>> On Jun/15/2018 at 11:34 PM, Fred J. McCall wrote : >>>> JF Mezei <jfmezei.spamnot@vaxination.ca> wrote on Fri, 15 Jun 2018 >>>> 22:13:01 -0400: >>>> >>>>> On 2018-06-15 19:21, Alain Fournier wrote: >>>>>> >>>>>> Yes. But I think I am a little less optimistic than you about it >>>>>> becoming practical in the future. If we have fantastic materials >>>>>> in the >>>>>> future, maybe an elevator will become more practical, >>>>>> >>>>> >>>>> Apart from lifting geostationary satellites to just below orbit and >>>>> then >>>>> let them use their own thrusters to position to their assigned >>>>> slot/longitude, what other use would a space elevator have ? >>>>> >>>> >>>> You go above the GEO point on the cable and get flung on >>>> interplanetary trajectories. >>> >>> Yes! >>> >>> You would also likely put at least one cable above GEO rotating in a >>> plane perpendicular to the main cable. So you can give an extra push for >>> interplanetary trajectories and to fine tune in which direction you >>> depart for said trajectories. >>> >>> You can also jump off at an altitude of about 15000 km (that figure is >>> from the top of my head, it might be more or might be less). From there >>> after a few passes of aero-braking you can reach LEO with very small >>> thrusters. >>> >>> For polar orbits, you use the rotating cable above GEO mentioned above. >>> But instead of using it for extra push you get off while it is >>> subtracting some speed but not quite in the direction of rotation of the >>> cable. So you subtract some speed in the direction of rotation of the >>> cable and give some speed in the north-south axis. You then use >>> aero-braking again to lower apogee, and a small thruster to raise >>> perigee. Note however that using the elevator to reach polar orbits in >>> this way isn't obvious. You would want a long and fast rotating cable >>> and you would want it far above GEO, it might not be practical to do so. >>> >>> Building an elevator, with current technologies, is outrageously >>> expensive. But if you have one, it can be very useful. >>> >> >> we don't have one, and never will. It is a joke among Engineers. >> >> What would is the monthly insurance payment for it? if it fell over ? > > You put the cable on an east coast. You also put a system to cut the > cable at something like 10000 km high. If the cable breaks below that > 10000 km the upper part doesn't fall it goes up, the bottom part falls > in the ocean, where it isn't likely to cause damage. If the cable breaks > higher than 10000 km, you cut it at 10000 km, the bottom 10000 km falls > once again in the ocean. The two other parts won't fall to the ground, > the lower part will probably be in an elliptical orbit, the higher part > might be in an escape trajectory. So the damage from a cable breaking > doesn't have to be high. It might be a little difficult to explain that > to an insurance company, but if you can pay for the cable, you should be > able to cover the damages. how much does 10,000 of cable weigh? 100,000 # the center of gravity is directly over the support, so you have 100,000# of steel cable crashing onto it. nothing will go into orbit as the accelleration vector is stright down, gravity. > >> how many miles would the top swing back and forth ? > > Why do you care? I asking to see if you know what you are talking about. 20,000 km is 12,427 miles, if you support the tower it will swing at least 2 degrees sin 2 degrees = 0.035 times 12427 = *434 miles* does the tip swinging wider than most states bother you ?? > >> How much sideways force is pushed on it by a 20 mph wind ? > > Why do you care? ...to evaporate your imagination with facts. > >> how much does one guy wire weigh ? (assume 20,000 km elevator height) > > Why would you put a guy wire? Don't assume 20,000 km elevator height, > assume 70,000 km, you want the top of the cable to pull up the bottom of > the cable, so you have to go beyond GEO height. so what is the weight of 70,000 km of cable to support 500# ? [there is no cable that will support itself 70,000 km, darling) > >> how much does one copper cable weigh if moving 200 amps ? > > Don't put a copper cable. Send energy to the climber using some kind of > beamed energy. (A laser on the ground, maybe another one in > geosynchronous orbit, and photocells on the climber to convert back to > electricity. Or something of that kind.) Use McGinn's patented plasma's and water vapor it up. What happens when you use a 1000 watt laser to shoot power to it ? the beam heats up the air and defocuses the beam and the power splinters out, the power does not get there. there is no know laser that can meet the dispersion requirements either (google dispersion laser) > >> What voltage is needed at the ground to feed the copper wires ? assume >> 500 V AC needed at the top. >> >> How much does the tower weigh counting only the copper wires, main >> cable, and guy wires ? > > The copper wires and guy wires are nonexistent and therefore weigh > nothing. As for the main cable, it weighs way too much. That is why I > said in the message to which you are replying that "Building an > elevator, with current technologies, is outrageously expensive." I don't > think we will ever have one. it is joke bate by Engineers, > > > Alain Fournier
[toc] | [prev] | [next] | [standalone]
| From | Fred J. McCall <fjmccall@gmail.com> |
|---|---|
| Date | 2018-06-19 00:45 -0700 |
| Message-ID | <jlchid9gihahhormkhe1om493u11529fbk@4ax.com> |
| In reply to | #691163 |
Sergio <invalid@invalid.com> wrote on Mon, 18 Jun 2018 22:17:21 -0500:
>On 6/18/2018 8:06 PM, Alain Fournier wrote:
>> On Jun/18/2018 at 2:45 PM, Sergio wrote :
>>> On 6/16/2018 8:54 AM, Alain Fournier wrote:
>>>> On Jun/15/2018 at 11:34 PM, Fred J. McCall wrote :
>>>>> JF Mezei <jfmezei.spamnot@vaxination.ca> wrote on Fri, 15 Jun 2018
>>>>> 22:13:01 -0400:
>>>>>
>>>>>> On 2018-06-15 19:21, Alain Fournier wrote:
>>>>>>>
>>>>>>> Yes. But I think I am a little less optimistic than you about it
>>>>>>> becoming practical in the future. If we have fantastic materials
>>>>>>> in the
>>>>>>> future, maybe an elevator will become more practical,
>>>>>>>
>>>>>>
>>>>>> Apart from lifting geostationary satellites to just below orbit and
>>>>>> then
>>>>>> let them use their own thrusters to position to their assigned
>>>>>> slot/longitude, what other use would a space elevator have ?
>>>>>>
>>>>>
>>>>> You go above the GEO point on the cable and get flung on
>>>>> interplanetary trajectories.
>>>>
>>>> Yes!
>>>>
>>>> You would also likely put at least one cable above GEO rotating in a
>>>> plane perpendicular to the main cable. So you can give an extra push for
>>>> interplanetary trajectories and to fine tune in which direction you
>>>> depart for said trajectories.
>>>>
>>>> You can also jump off at an altitude of about 15000 km (that figure is
>>>> from the top of my head, it might be more or might be less). From there
>>>> after a few passes of aero-braking you can reach LEO with very small
>>>> thrusters.
>>>>
>>>> For polar orbits, you use the rotating cable above GEO mentioned above.
>>>> But instead of using it for extra push you get off while it is
>>>> subtracting some speed but not quite in the direction of rotation of the
>>>> cable. So you subtract some speed in the direction of rotation of the
>>>> cable and give some speed in the north-south axis. You then use
>>>> aero-braking again to lower apogee, and a small thruster to raise
>>>> perigee. Note however that using the elevator to reach polar orbits in
>>>> this way isn't obvious. You would want a long and fast rotating cable
>>>> and you would want it far above GEO, it might not be practical to do so.
>>>>
>>>> Building an elevator, with current technologies, is outrageously
>>>> expensive. But if you have one, it can be very useful.
>>>>
>>>
>>> we don't have one, and never will. It is a joke among Engineers.
>>>
>>> What would is the monthly insurance payment for it? if it fell over ?
>>
>> You put the cable on an east coast. You also put a system to cut the
>> cable at something like 10000 km high. If the cable breaks below that
>> 10000 km the upper part doesn't fall it goes up, the bottom part falls
>> in the ocean, where it isn't likely to cause damage. If the cable breaks
>> higher than 10000 km, you cut it at 10000 km, the bottom 10000 km falls
>> once again in the ocean. The two other parts won't fall to the ground,
>> the lower part will probably be in an elliptical orbit, the higher part
>> might be in an escape trajectory. So the damage from a cable breaking
>> doesn't have to be high. It might be a little difficult to explain that
>> to an insurance company, but if you can pay for the cable, you should be
>> able to cover the damages.
>>
>
>how much does 10,000 of cable weigh? 100,000 #
>the center of gravity is directly over the support, so you have 100,000#
>of steel cable crashing onto it.
>
Nope. The Earth spins, you know. And STEEL? That's cute.
>
>nothing will go into orbit as the accelleration vector is stright down,
>gravity.
>
Well, no. When whole, the cable is under tension, not compression.
Remove weight from the bottom or break the tether point and it goes UP
above the break, not down.
>
>>
>>> how many miles would the top swing back and forth ?
>>
>> Why do you care?
>>
>
>I asking to see if you know what you are talking about. 20,000 km is
>12,427 miles, if you support the tower it will swing at least 2 degrees
>sin 2 degrees = 0.035 times 12427 = *434 miles*
>
>does the tip swinging wider than most states bother you ??
>
You're not smart enough to be asking questions. It's not a 'tower'.
>>
>>> How much sideways force is pushed on it by a 20 mph wind ?
>>
>> Why do you care?
>
>...to evaporate your imagination with facts.
>
That would be refreshing. When are you going to start?
>
>>
>>> how much does one guy wire weigh ? (assume 20,000 km elevator height)
>>
>> Why would you put a guy wire? Don't assume 20,000 km elevator height,
>> assume 70,000 km, you want the top of the cable to pull up the bottom of
>> the cable, so you have to go beyond GEO height.
>
>so what is the weight of 70,000 km of cable to support 500# ?
>
That rather depends on what it's made of.
>
>[there is no cable that will support itself 70,000 km, darling)
>
There is no cable that will support its own weight like that YET. You
really need to STFU until you educate yourself.
>
>>
>>> how much does one copper cable weigh if moving 200 amps ?
>>
>> Don't put a copper cable. Send energy to the climber using some kind of
>> beamed energy. (A laser on the ground, maybe another one in
>> geosynchronous orbit, and photocells on the climber to convert back to
>> electricity. Or something of that kind.)
>
>Use McGinn's patented plasma's and water vapor it up. What happens
>when you use a 1000 watt laser to shoot power to it ? the beam heats up
>the air and defocuses the beam and the power splinters out, the power
>does not get there.
>
>there is no know laser that can meet the dispersion requirements either
>(google dispersion laser)
>
Hogwash.
>>
>>> What voltage is needed at the ground to feed the copper wires ? assume
>>> 500 V AC needed at the top.
>>>
>>> How much does the tower weigh counting only the copper wires, main
>>> cable, and guy wires ?
>>
>> The copper wires and guy wires are nonexistent and therefore weigh
>> nothing. As for the main cable, it weighs way too much. That is why I
>> said in the message to which you are replying that "Building an
>> elevator, with current technologies, is outrageously expensive." I don't
>> think we will ever have one.
>
>it is joke bate by Engineers,
>
You wouldn't know an engineer if you tripped over one.
--
"Ignorance is preferable to error, and he is less remote from the
truth who believes nothing than he who believes what is wrong."
-- Thomas Jefferson
[toc] | [prev] | [next] | [standalone]
| From | Sergio <invalid@invalid.com> |
|---|---|
| Date | 2018-06-19 15:58 -0500 |
| Message-ID | <pgbqp6$jnl$1@gioia.aioe.org> |
| In reply to | #691180 |
On 6/19/2018 2:45 AM, Fred J. McCall wrote: > Sergio <invalid@invalid.com> wrote on Mon, 18 Jun 2018 22:17:21 -0500: > >> On 6/18/2018 8:06 PM, Alain Fournier wrote: >>> On Jun/18/2018 at 2:45 PM, Sergio wrote : >>>> On 6/16/2018 8:54 AM, Alain Fournier wrote: >>>>> On Jun/15/2018 at 11:34 PM, Fred J. McCall wrote : >>>>>> JF Mezei <jfmezei.spamnot@vaxination.ca> wrote on Fri, 15 Jun 2018 >>>>>> 22:13:01 -0400: >>>>>> >>>>>>> On 2018-06-15 19:21, Alain Fournier wrote: >>>>>>>> >>>>>>>> Yes. But I think I am a little less optimistic than you about it >>>>>>>> becoming practical in the future. If we have fantastic materials >>>>>>>> in the >>>>>>>> future, maybe an elevator will become more practical, >>>>>>>> >>>>>>> >>>>>>> Apart from lifting geostationary satellites to just below orbit and >>>>>>> then >>>>>>> let them use their own thrusters to position to their assigned >>>>>>> slot/longitude, what other use would a space elevator have ? >>>>>>> >>>>>> >>>>>> You go above the GEO point on the cable and get flung on >>>>>> interplanetary trajectories. >>>>> >>>>> Yes! >>>>> >>>>> You would also likely put at least one cable above GEO rotating in a >>>>> plane perpendicular to the main cable. So you can give an extra push for >>>>> interplanetary trajectories and to fine tune in which direction you >>>>> depart for said trajectories. >>>>> >>>>> You can also jump off at an altitude of about 15000 km (that figure is >>>>> from the top of my head, it might be more or might be less). From there >>>>> after a few passes of aero-braking you can reach LEO with very small >>>>> thrusters. >>>>> >>>>> For polar orbits, you use the rotating cable above GEO mentioned above. >>>>> But instead of using it for extra push you get off while it is >>>>> subtracting some speed but not quite in the direction of rotation of the >>>>> cable. So you subtract some speed in the direction of rotation of the >>>>> cable and give some speed in the north-south axis. You then use >>>>> aero-braking again to lower apogee, and a small thruster to raise >>>>> perigee. Note however that using the elevator to reach polar orbits in >>>>> this way isn't obvious. You would want a long and fast rotating cable >>>>> and you would want it far above GEO, it might not be practical to do so. >>>>> >>>>> Building an elevator, with current technologies, is outrageously >>>>> expensive. But if you have one, it can be very useful. >>>>> >>>> >>>> we don't have one, and never will. It is a joke among Engineers. >>>> >>>> What would is the monthly insurance payment for it? if it fell over ? >>> >>> You put the cable on an east coast. You also put a system to cut the >>> cable at something like 10000 km high. If the cable breaks below that >>> 10000 km the upper part doesn't fall it goes up, the bottom part falls >>> in the ocean, where it isn't likely to cause damage. If the cable breaks >>> higher than 10000 km, you cut it at 10000 km, the bottom 10000 km falls >>> once again in the ocean. The two other parts won't fall to the ground, >>> the lower part will probably be in an elliptical orbit, the higher part >>> might be in an escape trajectory. So the damage from a cable breaking >>> doesn't have to be high. It might be a little difficult to explain that >>> to an insurance company, but if you can pay for the cable, you should be >>> able to cover the damages. >>> >> >> how much does 10,000 of cable weigh? 100,000 # >> the center of gravity is directly over the support, so you have 100,000# >> of steel cable crashing onto it. >> > > Nope. The Earth spins, you know. And STEEL? That's cute. earth spin is red herring, do the math. what else are you going to use besides steel ? NOTHING can support its own weight of 10,000 km of it. go ahead, NAME what you propose to use. > >> >> nothing will go into orbit as the accelleration vector is stright down, >> gravity. >> > > Well, no. When whole, the cable is under tension, not compression. > Remove weight from the bottom or break the tether point and it goes UP > above the break, not down. no, gravity wins over whatever transitory events. > >> >>> >>>> how many miles would the top swing back and forth ? >>> >>> Why do you care? >>> >> >> I asking to see if you know what you are talking about. 20,000 km is >> 12,427 miles, if you support the tower it will swing at least 2 degrees >> sin 2 degrees = 0.035 times 12427 = *434 miles* >> >> does the tip swinging wider than most states bother you ?? >> > > You're not smart enough to be asking questions. It's not a 'tower'. what do you propose ? > >>> >>>> How much sideways force is pushed on it by a 20 mph wind ? >>> >>> Why do you care? >> >> ...to evaporate your imagination with facts. >> > > That would be refreshing. When are you going to start? what are you proposing ? > >> >>> >>>> how much does one guy wire weigh ? (assume 20,000 km elevator height) >>> >>> Why would you put a guy wire? Don't assume 20,000 km elevator height, >>> assume 70,000 km, you want the top of the cable to pull up the bottom of >>> the cable, so you have to go beyond GEO height. >> >> so what is the weight of 70,000 km of cable to support 500# ? >> > > That rather depends on what it's made of. you wont name anything, because it is all too heavy. got anything ? > >> >> [there is no cable that will support itself 70,000 km, darling) >> > > There is no cable that will support its own weight like that YET. You > really need to STFU until you educate yourself. and there never will be. do the math. check the materials, imaginarium won't work either. > >> >>> >>>> how much does one copper cable weigh if moving 200 amps ? >>> >>> Don't put a copper cable. Send energy to the climber using some kind of >>> beamed energy. (A laser on the ground, maybe another one in >>> geosynchronous orbit, and photocells on the climber to convert back to >>> electricity. Or something of that kind.) >> >> Use McGinn's patented plasma's and water vapor it up. What happens >> when you use a 1000 watt laser to shoot power to it ? the beam heats up >> the air and defocuses the beam and the power splinters out, the power >> does not get there. >> >> there is no know laser that can meet the dispersion requirements either >> (google dispersion laser) >> > > Hogwash. afraid to google for it ? why doen't the army shoot down missles with lasers ? -- dispersion and defocusing -- > >>> >>>> What voltage is needed at the ground to feed the copper wires ? assume >>>> 500 V AC needed at the top. >>>> >>>> How much does the tower weigh counting only the copper wires, main >>>> cable, and guy wires ? >>> >>> The copper wires and guy wires are nonexistent and therefore weigh >>> nothing. As for the main cable, it weighs way too much. That is why I >>> said in the message to which you are replying that "Building an >>> elevator, with current technologies, is outrageously expensive." I don't >>> think we will ever have one. >> >> it is joke bate by Engineers, >> > > You wouldn't know an engineer if you tripped over one. and you have no real facts for your "space elevator". > >
[toc] | [prev] | [next] | [standalone]
| From | Fred J. McCall <fjmccall@gmail.com> |
|---|---|
| Date | 2018-06-19 14:38 -0700 |
| Message-ID | <0itiid1psn6m5or70kd0urk0db4pll9e3f@4ax.com> |
| In reply to | #691256 |
Sergio <invalid@invalid.com> wrote on Tue, 19 Jun 2018 15:58:10 -0500:
>On 6/19/2018 2:45 AM, Fred J. McCall wrote:
>> Sergio <invalid@invalid.com> wrote on Mon, 18 Jun 2018 22:17:21 -0500:
>>
>>> On 6/18/2018 8:06 PM, Alain Fournier wrote:
>>>> On Jun/18/2018 at 2:45 PM, Sergio wrote :
>>>>> On 6/16/2018 8:54 AM, Alain Fournier wrote:
>>>>>> On Jun/15/2018 at 11:34 PM, Fred J. McCall wrote :
>>>>>>> JF Mezei <jfmezei.spamnot@vaxination.ca> wrote on Fri, 15 Jun 2018
>>>>>>> 22:13:01 -0400:
>>>>>>>
>>>>>>>> On 2018-06-15 19:21, Alain Fournier wrote:
>>>>>>>>>
>>>>>>>>> Yes. But I think I am a little less optimistic than you about it
>>>>>>>>> becoming practical in the future. If we have fantastic materials
>>>>>>>>> in the
>>>>>>>>> future, maybe an elevator will become more practical,
>>>>>>>>>
>>>>>>>>
>>>>>>>> Apart from lifting geostationary satellites to just below orbit and
>>>>>>>> then
>>>>>>>> let them use their own thrusters to position to their assigned
>>>>>>>> slot/longitude, what other use would a space elevator have ?
>>>>>>>>
>>>>>>>
>>>>>>> You go above the GEO point on the cable and get flung on
>>>>>>> interplanetary trajectories.
>>>>>>
>>>>>> Yes!
>>>>>>
>>>>>> You would also likely put at least one cable above GEO rotating in a
>>>>>> plane perpendicular to the main cable. So you can give an extra push for
>>>>>> interplanetary trajectories and to fine tune in which direction you
>>>>>> depart for said trajectories.
>>>>>>
>>>>>> You can also jump off at an altitude of about 15000 km (that figure is
>>>>>> from the top of my head, it might be more or might be less). From there
>>>>>> after a few passes of aero-braking you can reach LEO with very small
>>>>>> thrusters.
>>>>>>
>>>>>> For polar orbits, you use the rotating cable above GEO mentioned above.
>>>>>> But instead of using it for extra push you get off while it is
>>>>>> subtracting some speed but not quite in the direction of rotation of the
>>>>>> cable. So you subtract some speed in the direction of rotation of the
>>>>>> cable and give some speed in the north-south axis. You then use
>>>>>> aero-braking again to lower apogee, and a small thruster to raise
>>>>>> perigee. Note however that using the elevator to reach polar orbits in
>>>>>> this way isn't obvious. You would want a long and fast rotating cable
>>>>>> and you would want it far above GEO, it might not be practical to do so.
>>>>>>
>>>>>> Building an elevator, with current technologies, is outrageously
>>>>>> expensive. But if you have one, it can be very useful.
>>>>>>
>>>>>
>>>>> we don't have one, and never will. It is a joke among Engineers.
>>>>>
>>>>> What would is the monthly insurance payment for it? if it fell over ?
>>>>
>>>> You put the cable on an east coast. You also put a system to cut the
>>>> cable at something like 10000 km high. If the cable breaks below that
>>>> 10000 km the upper part doesn't fall it goes up, the bottom part falls
>>>> in the ocean, where it isn't likely to cause damage. If the cable breaks
>>>> higher than 10000 km, you cut it at 10000 km, the bottom 10000 km falls
>>>> once again in the ocean. The two other parts won't fall to the ground,
>>>> the lower part will probably be in an elliptical orbit, the higher part
>>>> might be in an escape trajectory. So the damage from a cable breaking
>>>> doesn't have to be high. It might be a little difficult to explain that
>>>> to an insurance company, but if you can pay for the cable, you should be
>>>> able to cover the damages.
>>>>
>>>
>>> how much does 10,000 of cable weigh? 100,000 #
>>> the center of gravity is directly over the support, so you have 100,000#
>>> of steel cable crashing onto it.
>>>
>>
>> Nope. The Earth spins, you know. And STEEL? That's cute.
>>
>
>earth spin is red herring, do the math.
>
You do the math.
>
>what else are you going to use besides steel ?
>
Almost anything.
>
>NOTHING can support its own weight of 10,000 km of it.
>
False. You really need to do some research.
>
>go ahead, NAME what you propose to use.
>
Carbon nanotubes.
>
>>
>>>
>>> nothing will go into orbit as the accelleration vector is stright down,
>>> gravity.
>>>
>>
>> Well, no. When whole, the cable is under tension, not compression.
>> Remove weight from the bottom or break the tether point and it goes UP
>> above the break, not down.
>>
>
>no, gravity wins over whatever transitory events.
>
Don't look now, but I think you just claimed that space satellites and
the Moon are impossible.
>
>>
>>>
>>>>
>>>>> how many miles would the top swing back and forth ?
>>>>
>>>> Why do you care?
>>>>
>>>
>>> I asking to see if you know what you are talking about. 20,000 km is
>>> 12,427 miles, if you support the tower it will swing at least 2 degrees
>>> sin 2 degrees = 0.035 times 12427 = *434 miles*
>>>
>>> does the tip swinging wider than most states bother you ??
>>>
>>
>> You're not smart enough to be asking questions. It's not a 'tower'.
>>
>
>what do you propose ?
>
And in that question you demonstrate just how clueless you are.
>
>>
>>>>
>>>>> How much sideways force is pushed on it by a 20 mph wind ?
>>>>
>>>> Why do you care?
>>>
>>> ...to evaporate your imagination with facts.
>>>
>>
>> That would be refreshing. When are you going to start?
>>
>
>what are you proposing ?
>
I'm proposing you start making sense (but I'm not holding my breath).
>
>>
>>>
>>>>
>>>>> how much does one guy wire weigh ? (assume 20,000 km elevator height)
>>>>
>>>> Why would you put a guy wire? Don't assume 20,000 km elevator height,
>>>> assume 70,000 km, you want the top of the cable to pull up the bottom of
>>>> the cable, so you have to go beyond GEO height.
>>>
>>> so what is the weight of 70,000 km of cable to support 500# ?
>>>
>>
>> That rather depends on what it's made of.
>>
>
>you wont name anything, because it is all too heavy.
>
>got anything ?
>
Jesus, go learn something. Right now you just sound abysmally stupid.
>
>>
>>>
>>> [there is no cable that will support itself 70,000 km, darling)
>>>
>>
>> There is no cable that will support its own weight like that YET. You
>> really need to STFU until you educate yourself.
>>
>
>and there never will be. do the math. check the materials, imaginarium
>won't work either.
>
I'm sorry you're clueless.
>
>>
>>>
>>>>
>>>>> how much does one copper cable weigh if moving 200 amps ?
>>>>
>>>> Don't put a copper cable. Send energy to the climber using some kind of
>>>> beamed energy. (A laser on the ground, maybe another one in
>>>> geosynchronous orbit, and photocells on the climber to convert back to
>>>> electricity. Or something of that kind.)
>>>
>>> Use McGinn's patented plasma's and water vapor it up. What happens
>>> when you use a 1000 watt laser to shoot power to it ? the beam heats up
>>> the air and defocuses the beam and the power splinters out, the power
>>> does not get there.
>>>
>>> there is no know laser that can meet the dispersion requirements either
>>> (google dispersion laser)
>>>
>>
>> Hogwash.
>>
>
>afraid to google for it ? why doen't the army shoot down missles with
>lasers ? -- dispersion and defocusing --
>
Uh, you haven't been paying attention, have you?
>
>>
>>>>
>>>>> What voltage is needed at the ground to feed the copper wires ? assume
>>>>> 500 V AC needed at the top.
>>>>>
>>>>> How much does the tower weigh counting only the copper wires, main
>>>>> cable, and guy wires ?
>>>>
>>>> The copper wires and guy wires are nonexistent and therefore weigh
>>>> nothing. As for the main cable, it weighs way too much. That is why I
>>>> said in the message to which you are replying that "Building an
>>>> elevator, with current technologies, is outrageously expensive." I don't
>>>> think we will ever have one.
>>>
>>> it is joke bate by Engineers,
>>>
>>
>> You wouldn't know an engineer if you tripped over one.
>>
>
>and you have no real facts for your "space elevator".
>
Go educate yourself and get back to us.
--
"Ignorance is preferable to error, and he is less remote from the
truth who believes nothing than he who believes what is wrong."
-- Thomas Jefferson
[toc] | [prev] | [next] | [standalone]
| From | Sergio <invalid@invalid.com> |
|---|---|
| Date | 2018-06-20 15:42 -0500 |
| Message-ID | <pgee8i$ujf$1@gioia.aioe.org> |
| In reply to | #691275 |
On 6/19/2018 4:38 PM, Fred J. McCall wrote:
> Sergio <invalid@invalid.com> wrote on Tue, 19 Jun 2018 15:58:10 -0500:
>
>> On 6/19/2018 2:45 AM, Fred J. McCall wrote:
>>> Sergio <invalid@invalid.com> wrote on Mon, 18 Jun 2018 22:17:21 -0500:
>>>
>>>> On 6/18/2018 8:06 PM, Alain Fournier wrote:
>>>>> On Jun/18/2018 at 2:45 PM, Sergio wrote :
>>>>>> On 6/16/2018 8:54 AM, Alain Fournier wrote:
>>>>>>> On Jun/15/2018 at 11:34 PM, Fred J. McCall wrote :
>>>>>>>> JF Mezei <jfmezei.spamnot@vaxination.ca> wrote on Fri, 15 Jun 2018
>>>>>>>> 22:13:01 -0400:
>>>>>>>>
>>>>>>>>> On 2018-06-15 19:21, Alain Fournier wrote:
>>>>>>>>>>
>>>>>>>>>> Yes. But I think I am a little less optimistic than you about it
>>>>>>>>>> becoming practical in the future. If we have fantastic materials
>>>>>>>>>> in the
>>>>>>>>>> future, maybe an elevator will become more practical,
>>>>>>>>>>
>>>>>>>>>
>>>>>>>>> Apart from lifting geostationary satellites to just below orbit and
>>>>>>>>> then
>>>>>>>>> let them use their own thrusters to position to their assigned
>>>>>>>>> slot/longitude, what other use would a space elevator have ?
>>>>>>>>>
>>>>>>>>
>>>>>>>> You go above the GEO point on the cable and get flung on
>>>>>>>> interplanetary trajectories.
>>>>>>>
>>>>>>> Yes!
>>>>>>>
>>>>>>> You would also likely put at least one cable above GEO rotating in a
>>>>>>> plane perpendicular to the main cable. So you can give an extra push for
>>>>>>> interplanetary trajectories and to fine tune in which direction you
>>>>>>> depart for said trajectories.
>>>>>>>
>>>>>>> You can also jump off at an altitude of about 15000 km (that figure is
>>>>>>> from the top of my head, it might be more or might be less). From there
>>>>>>> after a few passes of aero-braking you can reach LEO with very small
>>>>>>> thrusters.
>>>>>>>
>>>>>>> For polar orbits, you use the rotating cable above GEO mentioned above.
>>>>>>> But instead of using it for extra push you get off while it is
>>>>>>> subtracting some speed but not quite in the direction of rotation of the
>>>>>>> cable. So you subtract some speed in the direction of rotation of the
>>>>>>> cable and give some speed in the north-south axis. You then use
>>>>>>> aero-braking again to lower apogee, and a small thruster to raise
>>>>>>> perigee. Note however that using the elevator to reach polar orbits in
>>>>>>> this way isn't obvious. You would want a long and fast rotating cable
>>>>>>> and you would want it far above GEO, it might not be practical to do so.
>>>>>>>
>>>>>>> Building an elevator, with current technologies, is outrageously
>>>>>>> expensive. But if you have one, it can be very useful.
>>>>>>>
>>>>>>
>>>>>> we don't have one, and never will. It is a joke among Engineers.
>>>>>>
>>>>>> What would is the monthly insurance payment for it? if it fell over ?
>>>>>
>>>>> You put the cable on an east coast. You also put a system to cut the
>>>>> cable at something like 10000 km high. If the cable breaks below that
>>>>> 10000 km the upper part doesn't fall it goes up, the bottom part falls
>>>>> in the ocean, where it isn't likely to cause damage. If the cable breaks
>>>>> higher than 10000 km, you cut it at 10000 km, the bottom 10000 km falls
>>>>> once again in the ocean. The two other parts won't fall to the ground,
>>>>> the lower part will probably be in an elliptical orbit, the higher part
>>>>> might be in an escape trajectory. So the damage from a cable breaking
>>>>> doesn't have to be high. It might be a little difficult to explain that
>>>>> to an insurance company, but if you can pay for the cable, you should be
>>>>> able to cover the damages.
>>>>>
>>>>
>>>> how much does 10,000 of cable weigh? 100,000 #
>>>> the center of gravity is directly over the support, so you have 100,000#
>>>> of steel cable crashing onto it.
>>>>
>>>
>>> Nope. The Earth spins, you know. And STEEL? That's cute.
>>>
>>
>> earth spin is red herring, do the math.
>>
>
> You do the math.
you gave up.
>
>>
>> what else are you going to use besides steel ?
>>
>
> Almost anything.
like what ? anything real ?
>
>>
>> NOTHING can support its own weight of 10,000 km of it.
>>
>
> False. You really need to do some research.
name it, else you are lying.
>
>>
>> go ahead, NAME what you propose to use.
>>
>
> Carbon nanotubes.
they are held in a matrix of epoxy glue. your 10,000 km of glue wont
support itself.
>
>>
>>>
>>>>
>>>> nothing will go into orbit as the accelleration vector is stright down,
>>>> gravity.
>>>>
>>>
>>> Well, no. When whole, the cable is under tension, not compression.
>>> Remove weight from the bottom or break the tether point and it goes UP
>>> above the break, not down.
>>>
>>
>> no, gravity wins over whatever transitory events.
>>
>
> Don't look now, but I think you just claimed that space satellites and
> the Moon are impossible.
those are your words, now try to refocus on the topic, If your space
elevator is a cable in orbit, atmospheric drag ruins it.
>
>>
>>>
>>>>
>>>>>
>>>>>> how many miles would the top swing back and forth ?
>>>>>
>>>>> Why do you care?
>>>>>
>>>>
>>>> I asking to see if you know what you are talking about. 20,000 km is
>>>> 12,427 miles, if you support the tower it will swing at least 2 degrees
>>>> sin 2 degrees = 0.035 times 12427 = *434 miles*
>>>>
>>>> does the tip swinging wider than most states bother you ??
>>>>
>>>
>>> You're not smart enough to be asking questions. It's not a 'tower'.
>>>
>>
>> what do you propose ?
>>
>
> And in that question you demonstrate just how clueless you are.
again, no info from you. Because you have no idea what you are typing
about.
>
>>
>>>
>>>>>
>>>>>> How much sideways force is pushed on it by a 20 mph wind ?
>>>>>
>>>>> Why do you care?
>>>>
>>>> ...to evaporate your imagination with facts.
>>>>
>>>
>>> That would be refreshing. When are you going to start?
>>>
>>
>> what are you proposing ?
>>
>
> I'm proposing you start making sense (but I'm not holding my breath).
so you propose nothing, and state nothing, and know nothing.
>
>>
>>>
>>>>
>>>>>
>>>>>> how much does one guy wire weigh ? (assume 20,000 km elevator height)
>>>>>
>>>>> Why would you put a guy wire? Don't assume 20,000 km elevator height,
>>>>> assume 70,000 km, you want the top of the cable to pull up the bottom of
>>>>> the cable, so you have to go beyond GEO height.
>>>>
>>>> so what is the weight of 70,000 km of cable to support 500# ?
>>>>
>>>
>>> That rather depends on what it's made of.
>>>
>>
>> you wont name anything, because it is all too heavy.
>>
>> got anything ?
>>
>
> Jesus, go learn something. Right now you just sound abysmally stupid.
no reason to bring God into this, he cant help you.
>
>>
>>>
>>>>
>>>> [there is no cable that will support itself 70,000 km, darling)
>>>>
>>>
>>> There is no cable that will support its own weight like that YET. You
>>> really need to STFU until you educate yourself.
>>>
>>
>> and there never will be. do the math. check the materials, imaginarium
>> won't work either.
>>
>
> I'm sorry you're clueless.
and you still have nothing, as it does not exist.
>
>>
>>>
>>>>
>>>>>
>>>>>> how much does one copper cable weigh if moving 200 amps ?
>>>>>
>>>>> Don't put a copper cable. Send energy to the climber using some kind of
>>>>> beamed energy. (A laser on the ground, maybe another one in
>>>>> geosynchronous orbit, and photocells on the climber to convert back to
>>>>> electricity. Or something of that kind.)
>>>>
>>>> Use McGinn's patented plasma's and water vapor it up. What happens
>>>> when you use a 1000 watt laser to shoot power to it ? the beam heats up
>>>> the air and defocuses the beam and the power splinters out, the power
>>>> does not get there.
>>>>
>>>> there is no know laser that can meet the dispersion requirements either
>>>> (google dispersion laser)
>>>>
>>>
>>> Hogwash.
>>>
>>
>> afraid to google for it ? why doen't the army shoot down missles with
>> lasers ? -- dispersion and defocusing --
>>
>
> Uh, you haven't been paying attention, have you?
Just testing your depth of knowledge in the subject and it is 1/32 inch
deep. just another troll on the internet.
>
>>
>>>
>>>>>
>>>>>> What voltage is needed at the ground to feed the copper wires ? assume
>>>>>> 500 V AC needed at the top.
>>>>>>
>>>>>> How much does the tower weigh counting only the copper wires, main
>>>>>> cable, and guy wires ?
>>>>>
>>>>> The copper wires and guy wires are nonexistent and therefore weigh
>>>>> nothing. As for the main cable, it weighs way too much. That is why I
>>>>> said in the message to which you are replying that "Building an
>>>>> elevator, with current technologies, is outrageously expensive." I don't
>>>>> think we will ever have one.
>>>>
>>>> it is joke bate by Engineers,
>>>>
>>>
>>> You wouldn't know an engineer if you tripped over one.
>>>
>>
>> and you have no real facts for your "space elevator".
>>
>
> Go educate yourself and get back to us.
no need, you have demonstrated you know nothing in this thread.
you know nothing.
[toc] | [prev] | [next] | [standalone]
| From | JF Mezei <jfmezei.spamnot@vaxination.ca> |
|---|---|
| Date | 2018-06-20 16:58 -0400 |
| Message-ID | <tdzWC.96144$Kp4.27458@fx43.iad> |
| In reply to | #691393 |
On 2018-06-20 16:42, Sergio wrote: >> Carbon nanotubes. > > they are held in a matrix of epoxy glue. your 10,000 km of glue wont > support itself. Carbon nanotubes do not replace the primary carbon fibre structure. They are mixed with the epoxy to add strength to the matrix.
[toc] | [prev] | [next] | [standalone]
| From | Thomas Koenig <tkoenig@netcologne.de> |
|---|---|
| Date | 2018-06-25 20:44 +0000 |
| Message-ID | <pgrk86$ap$1@newsreader5.netcologne.de> |
| In reply to | #691394 |
JF Mezei <jfmezei.spamnot@vaxination.ca> schrieb: > On 2018-06-20 16:42, Sergio wrote: > >>> Carbon nanotubes. >> >> they are held in a matrix of epoxy glue. your 10,000 km of glue wont >> support itself. > Carbon nanotubes do not replace the primary carbon fibre structure. They > are mixed with the epoxy to add strength to the matrix. Or another material... With the problem of disentangeling the tubes, of binding the tubes to the matrix material (pulling out the fiber from the matrix is a common failure mode), and of course the fibers may have imperferfections which can _drastically_ (by quite a few orders of magnitude) reduce their strenghts. Is anybody aware of actual application of CNTs for materials, an application which has made it into the marketplace and that I could order today? I'm not, but I have not followed that field for some time.
[toc] | [prev] | [next] | [standalone]
| From | Fred J. McCall <fjmccall@gmail.com> |
|---|---|
| Date | 2018-06-20 17:07 -0700 |
| Message-ID | <9vqlid1bcn0cfh9vuavrj6k30sppaoapv4@4ax.com> |
| In reply to | #691393 |
Sergio <invalid@invalid.com> wrote on Wed, 20 Jun 2018 15:42:56 -0500:
>On 6/19/2018 4:38 PM, Fred J. McCall wrote:
>> Sergio <invalid@invalid.com> wrote on Tue, 19 Jun 2018 15:58:10 -0500:
>>
>>> On 6/19/2018 2:45 AM, Fred J. McCall wrote:
>>>> Sergio <invalid@invalid.com> wrote on Mon, 18 Jun 2018 22:17:21 -0500:
>>>>
>>>>> On 6/18/2018 8:06 PM, Alain Fournier wrote:
>>>>>> On Jun/18/2018 at 2:45 PM, Sergio wrote :
>>>>>>> On 6/16/2018 8:54 AM, Alain Fournier wrote:
>>>>>>>> On Jun/15/2018 at 11:34 PM, Fred J. McCall wrote :
>>>>>>>>> JF Mezei <jfmezei.spamnot@vaxination.ca> wrote on Fri, 15 Jun 2018
>>>>>>>>> 22:13:01 -0400:
>>>>>>>>>
>>>>>>>>>> On 2018-06-15 19:21, Alain Fournier wrote:
>>>>>>>>>>>
>>>>>>>>>>> Yes. But I think I am a little less optimistic than you about it
>>>>>>>>>>> becoming practical in the future. If we have fantastic materials
>>>>>>>>>>> in the
>>>>>>>>>>> future, maybe an elevator will become more practical,
>>>>>>>>>>>
>>>>>>>>>>
>>>>>>>>>> Apart from lifting geostationary satellites to just below orbit and
>>>>>>>>>> then
>>>>>>>>>> let them use their own thrusters to position to their assigned
>>>>>>>>>> slot/longitude, what other use would a space elevator have ?
>>>>>>>>>>
>>>>>>>>>
>>>>>>>>> You go above the GEO point on the cable and get flung on
>>>>>>>>> interplanetary trajectories.
>>>>>>>>
>>>>>>>> Yes!
>>>>>>>>
>>>>>>>> You would also likely put at least one cable above GEO rotating in a
>>>>>>>> plane perpendicular to the main cable. So you can give an extra push for
>>>>>>>> interplanetary trajectories and to fine tune in which direction you
>>>>>>>> depart for said trajectories.
>>>>>>>>
>>>>>>>> You can also jump off at an altitude of about 15000 km (that figure is
>>>>>>>> from the top of my head, it might be more or might be less). From there
>>>>>>>> after a few passes of aero-braking you can reach LEO with very small
>>>>>>>> thrusters.
>>>>>>>>
>>>>>>>> For polar orbits, you use the rotating cable above GEO mentioned above.
>>>>>>>> But instead of using it for extra push you get off while it is
>>>>>>>> subtracting some speed but not quite in the direction of rotation of the
>>>>>>>> cable. So you subtract some speed in the direction of rotation of the
>>>>>>>> cable and give some speed in the north-south axis. You then use
>>>>>>>> aero-braking again to lower apogee, and a small thruster to raise
>>>>>>>> perigee. Note however that using the elevator to reach polar orbits in
>>>>>>>> this way isn't obvious. You would want a long and fast rotating cable
>>>>>>>> and you would want it far above GEO, it might not be practical to do so.
>>>>>>>>
>>>>>>>> Building an elevator, with current technologies, is outrageously
>>>>>>>> expensive. But if you have one, it can be very useful.
>>>>>>>>
>>>>>>>
>>>>>>> we don't have one, and never will. It is a joke among Engineers.
>>>>>>>
>>>>>>> What would is the monthly insurance payment for it? if it fell over ?
>>>>>>
>>>>>> You put the cable on an east coast. You also put a system to cut the
>>>>>> cable at something like 10000 km high. If the cable breaks below that
>>>>>> 10000 km the upper part doesn't fall it goes up, the bottom part falls
>>>>>> in the ocean, where it isn't likely to cause damage. If the cable breaks
>>>>>> higher than 10000 km, you cut it at 10000 km, the bottom 10000 km falls
>>>>>> once again in the ocean. The two other parts won't fall to the ground,
>>>>>> the lower part will probably be in an elliptical orbit, the higher part
>>>>>> might be in an escape trajectory. So the damage from a cable breaking
>>>>>> doesn't have to be high. It might be a little difficult to explain that
>>>>>> to an insurance company, but if you can pay for the cable, you should be
>>>>>> able to cover the damages.
>>>>>>
>>>>>
>>>>> how much does 10,000 of cable weigh? 100,000 #
>>>>> the center of gravity is directly over the support, so you have 100,000#
>>>>> of steel cable crashing onto it.
>>>>>
>>>>
>>>> Nope. The Earth spins, you know. And STEEL? That's cute.
>>>>
>>>
>>> earth spin is red herring, do the math.
>>>
>>
>> You do the math.
>>
>
>you gave up.
>
On you? Yes, I certainly did. You're far too adamantly stupid.
--
"Ordinarily he is insane. But he has lucid moments when he is
only stupid."
-- Heinrich Heine
[toc] | [prev] | [next] | [standalone]
| From | Sergio <invalid@invalid.com> |
|---|---|
| Date | 2018-06-21 23:24 -0500 |
| Message-ID | <pghtmv$e2l$2@gioia.aioe.org> |
| In reply to | #691413 |
On 6/20/2018 7:07 PM, Fred J. McCall wrote: > Sergio <invalid@invalid.com> wrote on Wed, 20 Jun 2018 15:42:56 -0500: > >> On 6/19/2018 4:38 PM, Fred J. McCall wrote: >>> Sergio <invalid@invalid.com> wrote on Tue, 19 Jun 2018 15:58:10 -0500: >>> >>>> On 6/19/2018 2:45 AM, Fred J. McCall wrote: >>>>> Sergio <invalid@invalid.com> wrote on Mon, 18 Jun 2018 22:17:21 -0500: >>>>> >>>>>> On 6/18/2018 8:06 PM, Alain Fournier wrote: >>>>>>> On Jun/18/2018 at 2:45 PM, Sergio wrote : >>>>>>>> On 6/16/2018 8:54 AM, Alain Fournier wrote: >>>>>>>>> On Jun/15/2018 at 11:34 PM, Fred J. McCall wrote : >>>>>>>>>> JF Mezei <jfmezei.spamnot@vaxination.ca> wrote on Fri, 15 Jun 2018 >>>>>>>>>> 22:13:01 -0400: >>>>>>>>>> >>>>>>>>>>> On 2018-06-15 19:21, Alain Fournier wrote: >>>>>>>>>>>> >>>>>>>>>>>> Yes. But I think I am a little less optimistic than you about it >>>>>>>>>>>> becoming practical in the future. If we have fantastic materials >>>>>>>>>>>> in the >>>>>>>>>>>> future, maybe an elevator will become more practical, >>>>>>>>>>>> >>>>>>>>>>> >>>>>>>>>>> Apart from lifting geostationary satellites to just below orbit and >>>>>>>>>>> then >>>>>>>>>>> let them use their own thrusters to position to their assigned >>>>>>>>>>> slot/longitude, what other use would a space elevator have ? >>>>>>>>>>> >>>>>>>>>> >>>>>>>>>> You go above the GEO point on the cable and get flung on >>>>>>>>>> interplanetary trajectories. >>>>>>>>> >>>>>>>>> Yes! >>>>>>>>> >>>>>>>>> You would also likely put at least one cable above GEO rotating in a >>>>>>>>> plane perpendicular to the main cable. So you can give an extra push for >>>>>>>>> interplanetary trajectories and to fine tune in which direction you >>>>>>>>> depart for said trajectories. >>>>>>>>> >>>>>>>>> You can also jump off at an altitude of about 15000 km (that figure is >>>>>>>>> from the top of my head, it might be more or might be less). From there >>>>>>>>> after a few passes of aero-braking you can reach LEO with very small >>>>>>>>> thrusters. >>>>>>>>> >>>>>>>>> For polar orbits, you use the rotating cable above GEO mentioned above. >>>>>>>>> But instead of using it for extra push you get off while it is >>>>>>>>> subtracting some speed but not quite in the direction of rotation of the >>>>>>>>> cable. So you subtract some speed in the direction of rotation of the >>>>>>>>> cable and give some speed in the north-south axis. You then use >>>>>>>>> aero-braking again to lower apogee, and a small thruster to raise >>>>>>>>> perigee. Note however that using the elevator to reach polar orbits in >>>>>>>>> this way isn't obvious. You would want a long and fast rotating cable >>>>>>>>> and you would want it far above GEO, it might not be practical to do so. >>>>>>>>> >>>>>>>>> Building an elevator, with current technologies, is outrageously >>>>>>>>> expensive. But if you have one, it can be very useful. >>>>>>>>> >>>>>>>> >>>>>>>> we don't have one, and never will. It is a joke among Engineers. >>>>>>>> >>>>>>>> What would is the monthly insurance payment for it? if it fell over ? >>>>>>> >>>>>>> You put the cable on an east coast. You also put a system to cut the >>>>>>> cable at something like 10000 km high. If the cable breaks below that >>>>>>> 10000 km the upper part doesn't fall it goes up, the bottom part falls >>>>>>> in the ocean, where it isn't likely to cause damage. If the cable breaks >>>>>>> higher than 10000 km, you cut it at 10000 km, the bottom 10000 km falls >>>>>>> once again in the ocean. The two other parts won't fall to the ground, >>>>>>> the lower part will probably be in an elliptical orbit, the higher part >>>>>>> might be in an escape trajectory. So the damage from a cable breaking >>>>>>> doesn't have to be high. It might be a little difficult to explain that >>>>>>> to an insurance company, but if you can pay for the cable, you should be >>>>>>> able to cover the damages. >>>>>>> >>>>>> >>>>>> how much does 10,000 of cable weigh? 100,000 # >>>>>> the center of gravity is directly over the support, so you have 100,000# >>>>>> of steel cable crashing onto it. >>>>>> >>>>> >>>>> Nope. The Earth spins, you know. And STEEL? That's cute. >>>>> >>>> >>>> earth spin is red herring, do the math. >>>> >>> >>> You do the math. >>> >> >> you gave up. >> > > On you? Yes, I certainly did. You're far too adamantly stupid. > > no worries! I'll do it for you, since you are new to math and materials.
[toc] | [prev] | [next] | [standalone]
| From | Fred J. McCall <fjmccall@gmail.com> |
|---|---|
| Date | 2018-06-21 21:38 -0700 |
| Message-ID | <d6voidh6k0gtvom4un4uohlvc6bah062ab@4ax.com> |
| In reply to | #691521 |
Sergio <invalid@invalid.com> wrote on Thu, 21 Jun 2018 23:24:53 -0500:
>On 6/20/2018 7:07 PM, Fred J. McCall wrote:
>> Sergio <invalid@invalid.com> wrote on Wed, 20 Jun 2018 15:42:56 -0500:
>>
>>> On 6/19/2018 4:38 PM, Fred J. McCall wrote:
>>>> Sergio <invalid@invalid.com> wrote on Tue, 19 Jun 2018 15:58:10 -0500:
>>>>
>>>>> On 6/19/2018 2:45 AM, Fred J. McCall wrote:
>>>>>> Sergio <invalid@invalid.com> wrote on Mon, 18 Jun 2018 22:17:21 -0500:
>>>>>>
>>>>>>> On 6/18/2018 8:06 PM, Alain Fournier wrote:
>>>>>>>> On Jun/18/2018 at 2:45 PM, Sergio wrote :
>>>>>>>>> On 6/16/2018 8:54 AM, Alain Fournier wrote:
>>>>>>>>>> On Jun/15/2018 at 11:34 PM, Fred J. McCall wrote :
>>>>>>>>>>> JF Mezei <jfmezei.spamnot@vaxination.ca> wrote on Fri, 15 Jun 2018
>>>>>>>>>>> 22:13:01 -0400:
>>>>>>>>>>>
>>>>>>>>>>>> On 2018-06-15 19:21, Alain Fournier wrote:
>>>>>>>>>>>>>
>>>>>>>>>>>>> Yes. But I think I am a little less optimistic than you about it
>>>>>>>>>>>>> becoming practical in the future. If we have fantastic materials
>>>>>>>>>>>>> in the
>>>>>>>>>>>>> future, maybe an elevator will become more practical,
>>>>>>>>>>>>>
>>>>>>>>>>>>
>>>>>>>>>>>> Apart from lifting geostationary satellites to just below orbit and
>>>>>>>>>>>> then
>>>>>>>>>>>> let them use their own thrusters to position to their assigned
>>>>>>>>>>>> slot/longitude, what other use would a space elevator have ?
>>>>>>>>>>>>
>>>>>>>>>>>
>>>>>>>>>>> You go above the GEO point on the cable and get flung on
>>>>>>>>>>> interplanetary trajectories.
>>>>>>>>>>
>>>>>>>>>> Yes!
>>>>>>>>>>
>>>>>>>>>> You would also likely put at least one cable above GEO rotating in a
>>>>>>>>>> plane perpendicular to the main cable. So you can give an extra push for
>>>>>>>>>> interplanetary trajectories and to fine tune in which direction you
>>>>>>>>>> depart for said trajectories.
>>>>>>>>>>
>>>>>>>>>> You can also jump off at an altitude of about 15000 km (that figure is
>>>>>>>>>> from the top of my head, it might be more or might be less). From there
>>>>>>>>>> after a few passes of aero-braking you can reach LEO with very small
>>>>>>>>>> thrusters.
>>>>>>>>>>
>>>>>>>>>> For polar orbits, you use the rotating cable above GEO mentioned above.
>>>>>>>>>> But instead of using it for extra push you get off while it is
>>>>>>>>>> subtracting some speed but not quite in the direction of rotation of the
>>>>>>>>>> cable. So you subtract some speed in the direction of rotation of the
>>>>>>>>>> cable and give some speed in the north-south axis. You then use
>>>>>>>>>> aero-braking again to lower apogee, and a small thruster to raise
>>>>>>>>>> perigee. Note however that using the elevator to reach polar orbits in
>>>>>>>>>> this way isn't obvious. You would want a long and fast rotating cable
>>>>>>>>>> and you would want it far above GEO, it might not be practical to do so.
>>>>>>>>>>
>>>>>>>>>> Building an elevator, with current technologies, is outrageously
>>>>>>>>>> expensive. But if you have one, it can be very useful.
>>>>>>>>>>
>>>>>>>>>
>>>>>>>>> we don't have one, and never will. It is a joke among Engineers.
>>>>>>>>>
>>>>>>>>> What would is the monthly insurance payment for it? if it fell over ?
>>>>>>>>
>>>>>>>> You put the cable on an east coast. You also put a system to cut the
>>>>>>>> cable at something like 10000 km high. If the cable breaks below that
>>>>>>>> 10000 km the upper part doesn't fall it goes up, the bottom part falls
>>>>>>>> in the ocean, where it isn't likely to cause damage. If the cable breaks
>>>>>>>> higher than 10000 km, you cut it at 10000 km, the bottom 10000 km falls
>>>>>>>> once again in the ocean. The two other parts won't fall to the ground,
>>>>>>>> the lower part will probably be in an elliptical orbit, the higher part
>>>>>>>> might be in an escape trajectory. So the damage from a cable breaking
>>>>>>>> doesn't have to be high. It might be a little difficult to explain that
>>>>>>>> to an insurance company, but if you can pay for the cable, you should be
>>>>>>>> able to cover the damages.
>>>>>>>>
>>>>>>>
>>>>>>> how much does 10,000 of cable weigh? 100,000 #
>>>>>>> the center of gravity is directly over the support, so you have 100,000#
>>>>>>> of steel cable crashing onto it.
>>>>>>>
>>>>>>
>>>>>> Nope. The Earth spins, you know. And STEEL? That's cute.
>>>>>>
>>>>>
>>>>> earth spin is red herring, do the math.
>>>>>
>>>>
>>>> You do the math.
>>>>
>>>
>>> you gave up.
>>>
>>
>> On you? Yes, I certainly did. You're far too adamantly stupid.
>>
>
>no worries! I'll do it for you, since you are new to math and materials.
>
Gee, let's not tell the university. They might ask for my degree in
mathematics back. And certainly let's not tell Texas Instruments or
Raytheon, as they might want some of that salary back that they paid
me for being an engineer all those years.
--
"Ignorance is preferable to error, and he is less remote from the
truth who believes nothing than he who believes what is wrong."
-- Thomas Jefferson
[toc] | [prev] | [next] | [standalone]
| From | Greg Goss <gossg@gossg.org> |
|---|---|
| Date | 2018-06-19 21:35 -0600 |
| Message-ID | <fou0c6Fs27iU1@mid.individual.net> |
| In reply to | #691256 |
Sergio <invalid@invalid.com> wrote: >> Nope. The Earth spins, you know. And STEEL? That's cute. > >earth spin is red herring, do the math. >what else are you going to use besides steel ? >NOTHING can support its own weight of 10,000 km of it. > >go ahead, NAME what you propose to use. You're not hanging a simple cable. It tapers. The taper amount depends on the material. So they talk about boron filaments or buckeytubes. Still not there, but they make steel look "cute". >>> I asking to see if you know what you are talking about. 20,000 km is >>> 12,427 miles, if you support the tower it will swing at least 2 degrees >>> sin 2 degrees = 0.035 times 12427 = *434 miles* >>> >>> does the tip swinging wider than most states bother you ?? >>> >> >> You're not smart enough to be asking questions. It's not a 'tower'. > >what do you propose ? "If you support the tower" shows that you don't even understand the proposal. Nobody here is saying that any currently known material is practical for this, but you're clearly not even in the ballpark. -- We are geeks. Resistance is voltage over current.
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| From | Thomas Koenig <tkoenig@netcologne.de> |
|---|---|
| Date | 2018-06-19 17:01 +0000 |
| Message-ID | <pgbct9$tkg$1@newsreader5.netcologne.de> |
| In reply to | #691078 |
Sergio <invalid@invalid.com> schrieb: > On 6/16/2018 8:54 AM, Alain Fournier wrote: >> Building an elevator, with current technologies, is outrageously >> expensive. But if you have one, it can be very useful. >> > we don't have one, and never will. It is a joke among Engineers. Well, I did like the space elevator in "Red Mars". Spoiler: When it fell, Mars finally acquired a visible equator... it came down as some sort of continuous meteor.
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