Matthew Robinson wrote: > From the description I saw of the elevator, the habitat ring the kids were > on was at a lower altitude than geostationary orbit. That puts it moving
Hmm most of what you said is reasonably consistent with real world physics. Good job. Except that I still cannot imagine why would the designer put any significant components (e.g. the gravity blocks) below the geosyn orbit. Especially, as low as where they are, where a minor mishap gives only 7-14 minutes for remedial measures. If the "lower ring" is placed where according to the scene when Louise fell at what looks like 1/10 to 1/6 g. (it's actually very easy to measure her fall from that scene and calculate very accurately how high up the lower ring is). Then the weight of the entire lower ring must be in the range of a thousand to a million tons. What is supposed to support that weight? The outer ring? Then the outer ring must be place way way higher then geosyn orbit to pull up all that weight. Now what's being used to keep the outer ring and inner rings together? Some super strong material perhaps, maybe even the same tether material for the space elevator. Sure, but there still need to be say, a ton of tether material to support a thousand ton at 1000 km separation (very conservative here). What purpose is served for placing infrastructure that low? How much excessive construction material is needed to build structure strong enough to support a 0.1g environment? How ridiculously dangerous and wasteful it is to have spacewalk, MS or cargo flight in 0.1 g environment? You have all the danger and peril of space, requiring life support for humans, but minus the big benefit: free flight so you need expend fuel + propellant just to stay "still". > around the Earth at a lower speed than would provide a stable orbit, so the > direction of fall seems right. For the blocks to fall outward, it would > have to be above geostationary -- much farther out. Also, regarding the Correct, but you agree that something massive must be placed above geosyn orbit in order for the space elevator to be built right? It must be massive enough to at least pull up the weight of the tether (space elevator). Just seems too sensible to put all the infrastructure above or precisely at geosyn orbit just to prevent the kind of drama in ep.5. If there's some mishap, you either "fall" very slowly outward, or ideally not fall at all. If you let go, you stay "still". It should make everything, especially construction so much easier. > of the train decelerating as it approached the ring. I'm guessing it > accelerates pretty fast as it initially leaves Earth, then coasts to a stop Ha... it needs to, to travel the nearly 40,000km in under 4 hours, you are going at 10,000 km/hr average. To accelerate and decelerate with minimal discomfort... you get 0.77 m/s^2 or 0.08g. Hmmm that's well under the discomfort level, so it's ok to accelerate/decelerate harder... OK I'm sold. Pseudo zero-g is well within reason. > as it approaches the station at a rate that provides free-fall for the > passengers (it would seem to me that you really could free-fall UP if you > started out fast enough and were slowing down...). In fact, we could Precisely, braking is a waste of energy, even with energy recovery device. So you would accelerate the linear train up to a certain speed, disengage the motor, and let gravity pulls the train to a stop. To save energy, you would want the gravity to stop the train at precisely the terminal station, but if it's at geosyn orbit, it will take forever (any physics major should understand why). To save travel time, you will speed the train a bit more than needed to reach geosyn altitude, let gravity slows it down to a gentle coast, than apply braking as the train approach the station. Either way, there's a period of "gravity braking" which is (thanks to Einstein) free fall or zero-G. > probably calculate how fast they were decelerating if we knew the altitude > of the gravity block. Indeed the equation is pretty simple. But honestly I don't feel like working it out now, it's getting a little too technical for the list. > Another note -- shouldn't the gravity block be on a slight angle? You'll Correct, but we hardly had a good look at the gravity blocks, so there might have been an incline. But beyond that, I just find the idea of building anything below geosyn altitude to be too absurd to contemplate. > Good point on the gravity block breaking apart with the sections missing. > Only way I could see it holding together would be if the habitable parts are > all attached to a much heavier ring, and the wild shots from the Super Fine you can think of many possible structure/configuration that would at the same time leave a few blocks highly vulnerable to break apart from conventional (MS-size) firearms, while leaving the rest of blocks maintaining integrity. But remembering Schenberg was both the architect of the space elevator and now looking a little saintly from CB's life-saving heroism. The populations of 2307 should start to see some conspiracy theories about how the gravity blocks are designed so awkwardly or precisely to create the dramatic crisis that make CB looks so _Celestial_. Ok ok... the episode really really sucks. But the outcome is that: Sergei has a good side to him; Allelujah has a back story; Soma is unstable and we can guess NT is going to play in the plotline. An interesting question is if Schenberg/Vega/Sumeragi knew about Soma/Allelujah's vulnerability to have NT-triggered berserker events. Or is this the long-awaited monkey wrench in CB's master plan? (yes some of you may know which Sci-fi classics I am thinking of) -- Dr. Core -------------------------------------------------- The Gundam Mailing List MK-II [email protected] Archives: http://www.gundam.com/gml Help: Email [EMAIL PROTECTED] with this in the BODY: help list
