It seems to me that your iris airlock wouldn't work. Imagine what the air rushing in would do to the speed of your projectile when you opened it. How does your projectile transition from the evacuated region to the non-evacuated region without hitting this problem? You would need a theoretical airlock that could open instantaniously and at the last second.
Thats correct, which is why we use an iris airlock. Air pressure and density above the troposphere is considerably lower than sea level, but in any case I would envision the vessels themselves to be needle shaped, with three fins for the maglev rail. Rather kewl, actually, and it would lend itself to a "rifling effect" further enhanced by the lateral coriolis force inherent in magnetic propulsion, for stability. As to how fast it can click open and closed, how fast is a computer? Besides, an airlock is two doors. Once it passes the bottom one, that closes, and the top one opens simultaneously, to the transition to atmosphere would be fairly gradual (after a fashion).
There is no way this works for human payloads without additional thrust after you leave the tube
Only if you need to hit escape velocity, which as it turns out, you don't. For GEO its perfectly adequate.
People are working on exactly such a design
Who? As far as I know this combination of technologies is entirely unique. I know I certainly came up with it under my own steam. You can even watch the process of that happening in the linked discussion.
but if you can't get up to full speed within your structure's length, why not do away with the tube entirely?
Because an evacuated tube is needed to negate the effects of friction at lower altitudes, otherwise you gain nothing by using maglev, as opposed to chemical propulsion.
but it's non trivial to accelerate beyond certain speeds using maglev style propulsion.
The research here has already been done, with proposals for a transatlantic evacuated tube containing a maglev train. Its really not practical, the cost is something fantastical, but it reaches something like 1/8 escape velocity at its top speed, if I recall correctly. And designs do not call for dedicated nuclear plants to power it.
If you're not reaching orbital velocity without independant thrust, you don't need the evacuated tube.
Well as far as I can see, you are reaching orbital velocity, at a 5 gee acceleration. And with this system, its much cheaper to launch, requiring only SSTOs and enabling a far higher payload. As an added benefit, if you want to launch robotic missions (like most of the ones over the last 30 years), just ramp up the juice and escape velcoity there you go!
Serious research starts with a sanity check on what you've already got. Why are you attacking the people doing just that? I didn't say this couldn't be done... Just that it wasn't really a "current technology" kind of project.
I never let sanity get in the way of a good idea. I doubt the wright brothers did either when they built their flying-tent-crossed-with-shopping-cart. Anyway, my apologies if you felt I was attacking you, I opened up this idea to the community hoping to hear both positive and negative reactions, but I just had a skirmish with a rather nasty poster and I was feeling a bit raw. Your opinions and ideas are more than welcome! As for current technology, I stick to my guns when I say we can do this right now, and the benefits would be overwhelming.
Zero gee mining, heres a notion. Its like eating a half ton of cheese; you can't fit your mouth around it. So you cut it up into smaller segments, with cheesewire. So lets take say a rectangular frame of adjustable size (from a few hundred meters to many kilometers), power it with solar power, even a satellite ring of solar reflectors which it deploys when it reaches its target. These power lasers or some kind of diamond saw arrangement going from one side of the framework to the other, which slice the asteroid up. That doesn't resolve your problems, however, since now you have slices of asteroid falling all over the shop.
So when a laser passes through a segment of rock, foam of a sticky sort gets pumped in behind it (I don't think this exists right now, but its not impossible, I am sure) to keep the bits stuck together. Then, just keep cross sectioning the rock until you have manageable bits, which can be broken off. Then the third part of the ensemble comes into play.
The refinery, nearby, would be fed chunks of asteroid, and superheat them to seperate components. Not having gravity, a massive centrifuge (centriforge?) would be needed to seperate the parts into their elements. Split up, cooled, and shaped, these ingots of asteroidy goodness could then be shipped back to a manufactory in orbit, or processed on the spot (unlikely given the complexity of the components to be designed, circuit boards, ceramics, the lot). Even bare rock could be used as nutrients for algae pods.
Since we don't know whats out there, I can't begin to say which components could possibly be manufactured in space, and which would need earth based supplies, at least at first. Once we have a vast stream or streams of ore sailing back towards earth, dozens of these rigs slicing up rocks, and more being built, the sky is indeed the limit. Also another factor is that cutting up even one decent sized asteroid might take years, so it might be better just to slice off bits from it, maybe encase it in some kind of foam or resin first for stability.
Yes, I thought something was amiss, and I barely understood the equation, heheh. I have been thinking about the fact that its relatively easy to insert something into GEO with this system (and very very cheap, comparitively speaking). It would be an idea to build components for further exploration up there, since its far easier to escape the earth's gravity well from GEO than from the surface, especially if you can move a few thousand tons of components up there every day. Not to mention that if you combine this system with a chemical propellant (much less than would be needed for the shuttle, for example), you could go pretty much anywhere you liked.
Also, I discussed building it laying down with Carlton Meyer, the skyramp guy. Apparently almost all of it would have to be vertical or you're dealing with some serious forces that we really don't have the engineering to handle right now.
If you had read my response, you would have realised that the evacuation is a non-issue. And the acceleration is not unfeasable, just incredibly bad for the health. The more people I talk to, the more realisation I have that the acceleration is a serious issue. However it appears now that this system is very useful for getting people and equipment into geosynchronous orbit, at a miniscule fraction of the current cost, and en masse. And keep in mind that this is without chemical rocket assistance. If you add even a small amonut of extra thrust (nowhere near what the shuttle uses) you can go just about anywhere you like. But orbit is sufficient for now. Once there, the rest of my suggestions could easily be put into play. Its a whole lot easier to get from orbit to escape than it is to get from ground to escape, especially when you can shuttle up components at a rate of a few thousand tons a day.
One way or the other I have gotten some wildly variant responses in terms of the acceleration required and its effects, which tell me that a lot of people really have no idea. Also its worth mentioning that this system would effectively shelve any space elevator ambitions for the forseeable future, so I am getting a lot of flak from that crowd. Some serious research shall be done.:D
Just doing a "back of the envelope" calculation and an understanding of raw structural engineering, I fail to see how you can get a tube up that high.
Did you even read the links? Your back of the envelope calculations are inkorrekt, baby. They were designing mile high skyscrapers back in the 30's. The rest of your post rather falls into place from there.
space elevator as well, which is equally exotic but at least has some significant more engineering which has gone into the design and development of such systems.
Okay, I didn't want to have to do this, but I suppose it was inevitable. Equally exotic? Are you mad? We do not have now, or are ever likely to have, the kind of materials required for a space elevator. We don't even know if they are physically possible. Like impossible in the same way as super-relativistic speeds are impossible. I remember one poster in a previous discussion pointing out that it was like time travelling sneakers. Shoelace tying functionality, 100%. Rubber sole attachment, check. Time travelling, still working on it. I'll tell you what, read the links I supplied, then you can return and spout whatever you like. Until such time as you do, you have no right to be contributing to this discussion.
So an 11km launch tube, going at 5 gees, gets us almost 8% of escape velocity. And you're telling me that a tube 1232km long is needed for full escape velocity? Methinks I need to hire an actual physicist for a couple of days to get the facts here, cos a whole lotta numbers ain't adding up.:D
Okay, I was breaking it down into much smaller units, not dealing with the entire launch, sort of like changing speed from 10,000m/s to 10,001m/s over a space of 1m. Obviously as the speed gets higher the time to effect this change gets much much smaller, over the 1m distance. So the problem is the cumulative application of energy? Changing from 10,000m/s to 10,001m/s over 1m, whether it takes 1 second or.00001 seconds, is still just a change of 1m/s. Okay, I see the point here.
Right now I'm thinking of either a taller tower and / or chemical propellant after it pops out the top. One poster above suggested that at 5 gees, it would be enough to reach geostationary orbit, so it still offers massive advantages over anything we have now, especially in terms of cost per launch and time to launch. Twenty or thirty km high? Hmmm...
I think I'll post this again in a later discussion, I was a bit late to the party this time around. If it pans out anyway well, I'll go ahead and set up a feasability study with some investors, I reckon.
Wait something is fishy here. 2 seconds to traverse the launch tube is wildly out there. Even to accelerate to 30m/s would take a lot longer than that. What you are looking at with this system is a slower initial acceleration, and then power being applied every meter (perhaps in increasing amounts) via a maglev system (one or more rails). So the time taken to cross each 1m second becomes shorter and shorter, but the actual speed increase (in terms of pressure) stays the same. Its not like a cannon blast. And how do cars reach 27m/s in 3 or 4 seconds? I think your numbers are a little off, there.
Yes indeed, I was fascinated by the idea of "ironbergs" in the Peter F. Hamilton neutronium alchemist series, basically they infuse an iron asteroid with nitrogen or something and it airbrakes down to terminal velocity when it lands. I have no idea how feasable that really is though.
The global destruction end of things will definetely lead to some creative defence technology as well. I mean when you think about it, if we can build spaceships weighing a half million tons and capable of doing.2 C, any pilot could pop a hole in one side of the earth and pop out the other. Well maybe not, but certainly annihilate civilisation as we know it. Tricky times ahead, one way or the other.
I haven't read your links yet, but I'm skeptical about this being "readily achievable with today's technology."
Well you might have a look at the links before you go shooting down the structural engineering end of things. As far as I can see, its very doable. The point of the top being 11 km in the air is that it sticks out above the troposphere, so burying it 11km underground or undersea defeates the purpose. Thats 11km above sea level. Anyone popping out at escape velocity into dense atmosphere is going to have a lousy afternoon. In the links they are talking about a standard chemical launch from the top; I'm talking about using that height to gain speed. And the discussions cover towers hundreds of kilometers tall, its fascinating stuff.
you've got to pump air out faster than it flows in the open top, or add the mass of a cover to the top
Yes, so you put an iris airlock at the top, and just keep it evacuated. Whatever air gets in (not at sea level air pressures of course, much much less) you just pump out of the airlock between launches.
I also went ahead and did some quick math. 1 m/s/s acceleration over 11 km is not enough:
Okay I'm not an engineer or a physicist, so I was a bit fuzzy on this whole area here. I was working it from 1m per second acceleration every single meter traversed (based on distance not time elapsed), bringing you to 11,000m/s when you pop out the top; am I completely off base in that? Assuming I am, how much taller would the tower need to be built to get escape velocity, or would adding chemical propellants once it is clear of the tower have much effect? Certainly much, much less propellant would be required in the latter case than is currently needed, I think.
requires 2.4 MW of power, not accounting for losses, which is one capability we do easily have
Yes, thats where the nuclear power station(s) I mentioned come in, 40mwe to 2000mwe for a normal plant. Financially very doable as well, as these things go.
It's a pity, because all of these ideas show some measure of original thought and are theoretically feasible in some fashion, but the technical challenges are rather mind-numbing.
Not a bit, they are all doable with what we have today. The scale may be somewhat grandiose, but what should be looked at are the potential returns, which I outlined in the original post there. I'm not out to discredit the space elevator idea, if it ever works I'll be happier than anyone, but I just don't see it working anytime soon. We can build the tower right now!:D
Thank you for your comments by the way, I don't know a lot about this field, but I'm trying to build up a theoretical model, and criticism is good!
Its not FTL but baby will it get the ball rolling. I'll just run this by everyone here... With all the talk lately about a space elevator, I got to thinking after a sort of recent slashdot discussion, just what advantages would a space elevator offer over a tower launch? I contacted the man responsible for a similar idea, the skyramp (warning: hideous javascript menu may break firefox), Carlton Meyer, and had a dialogue in which he pointed me to a tower launch archive.
The ideas I see bandied about there are similar to what I had in mind, which would be essentially an 11km tall tower (think pylons rather than skyscrapers, based at sea), with evacuated airless launch tubes, using nuclear reactors to power a maglev or pulley system to accelerate vessels to escape velocity. These would then emerge above the end of the troposphere, with it's associated weather and air pressure, and have little to no fuel needed to escape the earth's gravity, meaning you could do a lot more while you were up there. At 1m/s acceleration, you would be at escape velocity when you exit the top of the tower.
Not only would this enable multiple launches daily, it is, unlike the space elevator, readily achievable with today's technology, and financially viable as well. Given NASA had an annual budget of $16.2 billion for 2005, and a nuclear power plant costs a cool billion to build, give or take, we could have this up and running in a few years. And once we are up there...
Space has got vast, essentially unlimited resources. One recent story pointed out the trillion dollar iron asteroid up there. The thing has about 5 tons of steel for every man, woman and child on earth. And thats just one of god knows how many... billions more?
Once we leap the cost to escape hurdle (as I think I have managed), we can proceed to use these resources. There are several obstacles in the way of this, first of which is zero gee mining, we have no idea how to do it. We can either mine the ore out there, or bring the asteroid back into orbit and slice it up there. Or slice it up and send it back to orbit. I would be opposed to moving it back into orbit for processing, purely for the debris issue. Perhaps a lunar base would have some merit there.
So we set up a mining and processing operation either on the moon or in deep orbit, and start cutting and processing one of those bad boys. Whats the first thing we build? A bigger processing and mining operation. Space exploration, much like the internet, has to be a largely incestuous affair at first, existing solely for its own benefit.
Once we have that mastered, we can move to algae pods in orbit for food production, oxygen refining, and fuel production (biodiesel or chemical engines), all of which can be powered by the immense energy of the sun, and use the raw materials abundantly available in space. Whether you ship that stuff back to earth or use it for further colonisation, its a vital step.
The production of automated scouts is also a high priority; a vast amount of surveyor and prospector drones to sweep and map every square inch of every rock and gas in the system, out to the Oort cloud, and figure out what they are made of. I'd err on the side of quantity rather than quality, still no reason not to have either. This could be combined with deep space observatories that would make hubble look like the end of a coke bottle.
So now we have a manufacturing bridgehead, a good idea of what's interesting out there, and a cheap means to launch to orbit. Actual manned system ships would come next, to either colonise or investigate the system. The rest, as they say, is (future) history.
Well coward, that works out at 10m x 10m for every man, woman and child, or about 25m by 25m for every family of five. You can't fit in that, coward, you really are justifying the fat ass american cliche. Keep sucking down those cheeseburgers, baby.
Disruptive change never comes about via the masses.
What masses. Masses are composed of people, individual units. Le Bon's contagion theory of mass psychology has been fairly comprehensively disproven, to my satisfaction at least. There is no group mind. Just because they are not assembled in a mob at this exact moment in time does not make them any more or less susceptible to crowd psychology (Turner and Killian's diffuse crowds), as in this case, the internet. Even marketing, the art of influencing the masses and crowd psychology, is ultimately targeted at the lowest common denominator; a scattershot approach designed to attract individuals, as many as possible.
it would appear that smart people are on the rise.
Smart, stupid. Such a vast amount depends on the environment that one's genetic makeup rarely has anything but a passing influence on comparitive intelligence. Sorry for that, eugenics, back to the drawing board, I'm afraid.
In the overpopulation of our planet
The planet is so far from overpopulated its not even funny. You could quite comfortably fit the entire population of the planet in the state of Texas, and I don't mean three high, I mean a house and land each. The perception of overpopulation is a misconception.
try convincing billions that you are right!
If you are right, you are right. The opinion of billions does not make you less so. Sooner or later they will have to come to accept your point of view. Draw your conclusions, base your future actions on that, and move on.
Communism would have been a massively disruptive change (on paper), but once it was implemented, people were able to smash it back down into the monarchy they were accustomed to
People didn't smash it anywhere. A few individuals did, taking advantage of a poorly educated, impoverished, and frankly terrified population. I have tremendous faith in humanity and its ability to ultimately rectify its own shortcomings. Denigrating the teeming masses really isn't helping anything. Anyway communism was a fundamentally flawed social theory. Marx sadly did not think it through to its logical conclusion. What he did manage to do was sully the waters sufficiently that any even vaguely similar system can immediately be branded "communism" by those with a lot to lose in such a system. Indeed, any system outside the current one.
Do you really envision slavering mobs of semi intelligent buffons marauding up and down the countryside, crushing new ideas anywhere they go?
Ah, yes, Pubmed: the home of 20 years of total hogwash stored in one compleat archive. Right up there with the UC San Francisco Pharmacy School as the world's leading research center into ignorant and racist thought.
Yes, highly skilled in both anthropology and history there too. Or wait, no. Don't get me wrong, I have no quarrel with their findings, which I am sure are accurate, or as much as they can be, which given the state of medicine generally, ain't that much. However you would not be the first to take good(?) science and turn it to a sly dig.
"His incorrect conclusions"? You're an outstanding poster child for someone who is willing to disregard peer-reviewed research...blah blah blah... world.
See above for details. Pharmacology does not an accurate picture of history make.
I would reference my European History textbook, but it doesn't have the advantage of being online like Wikipedia does.
European history textbook, hmmm... no, I've never heard of this hallowed tome. And I did European History.
I'm ethnically almost half Irish and have an Irish last name
Sigh. Just out of interest, rather than the many points I could raise here, why don't I just ask how one can be "almost half Irish". Was there surgery involved? Having been born and raised in Ireland, ethnically all Irish, and being able to trace my roots back a thousand years, I'm still calling bullshit on your argument. I might know, having been born and raised here and all. 0% my arse.
Find a reference to prove me wrong
You're the one asserting that the people of the republic of Ireland are alcohol dependants, and have been for thousands of years. The burden of proof lies with you.
It's always fun Europeans learn a little bit about their own history from Americans.
Kind of weird, but if this shapes up to have a 70% mortality rate, then it is what will be needed to survive. Not just for personal self, but also for our children.
What exactly do you mean by this? You are aware that the entire worlds population could fit very comfortably in an area the size of Texas? I don't mean piled three high, I mean a house and land each. You aren't one of these people that think the population needs "weeding out"?
If you ever did work at the CDC, I sincerely hope they fired your ass long, long ago.
Maybe agarwal should have studied the effects of extended alcohol consupmtion on people before wobbling to his incorrect conclusions then. Still, you do seem to have a lot of research to back you up there, its understandable if you swallowed it whole.
Ah yes, the wikipedia, even more reliable sources of information. I can't be bothered to look up the article now, but I recall reading one worthy had written up an article about how european men had smaller willies than american men. Truly a rock of reliability. As for vitriol, sufficient unto the day, the evil thereof. I have learned a few things however, probably not what you think, though.
The January/2006 Wired had an article titled "How Click Fraud Could Swallow the Internet"
Just a point of interest here, the only thing click fraud is going to swallow is google. The rest of the internet will get by just fine. Honestly the only types of online advertising I would pay for would be fixed fee (and I'd only try that for a short period to see results) or affiliate advertising, where clicks are attributed to referrers and tracked directly to sales. When sales are made, the referrer gets a commission.
Honestly google should have their heads examined, basing their whole business model on pay per click. This settlement will be the first of many, mark my words.
which would greatly increase the chances of contracting disease.
Nah given even basic statistical gradients, your assumptions are wildly inaccurate. Wildly.
Perhaps you should keep your outrage in check until you finish understanding what is written.
Are you saying all Irishmen are hot headed maniacs who fly off the handle at the least provocation? RaARAaaARRRR (head asplode)(joke).
The world reknowned anthropologist and history professor. Oh wait he's not. Try do a little better next time you quote your dependable sources. Hint: sci fi writers don't count.
as a result a total innability to drink alcohol would have quickly resulted in death.
Wow. Did you just say that anyone that couldn't drink alcohol in Europe would have died during the middle ages? This displays an ignorance so profound it defies belief, both of European history and of what happens to people who drink alcohol continuously. There were various extended periods during Irish history that the general population couldn't afford to eat, never mind afford to drink alcoholic beverages. Thats why the population is smaller now than it was in the 1840s. And have you ever met anyone that has replaced all of their liquid intake with beer and/or other spirits? I sincerely doubt you have, because they generally don't survive longer than a few months, if that.
And having travelled and lived in many parts of asia, I can tell you that alcohol intake is just as prevalent (and has been historically) as in the west. Slightly less so, but not enough to make a difference. So basically your post is just as much bullshit as the other guys.
Pull nonsense figures out of your arse, get called on it.
Slashdot Mirror
It seems to me that your iris airlock wouldn't work. Imagine what the air rushing in would do to the speed of your projectile when you opened it. How does your projectile transition from the evacuated region to the non-evacuated region without hitting this problem? You would need a theoretical airlock that could open instantaniously and at the last second.
Thats correct, which is why we use an iris airlock. Air pressure and density above the troposphere is considerably lower than sea level, but in any case I would envision the vessels themselves to be needle shaped, with three fins for the maglev rail. Rather kewl, actually, and it would lend itself to a "rifling effect" further enhanced by the lateral coriolis force inherent in magnetic propulsion, for stability. As to how fast it can click open and closed, how fast is a computer? Besides, an airlock is two doors. Once it passes the bottom one, that closes, and the top one opens simultaneously, to the transition to atmosphere would be fairly gradual (after a fashion).
There is no way this works for human payloads without additional thrust after you leave the tube
Only if you need to hit escape velocity, which as it turns out, you don't. For GEO its perfectly adequate.
People are working on exactly such a design
Who? As far as I know this combination of technologies is entirely unique. I know I certainly came up with it under my own steam. You can even watch the process of that happening in the linked discussion.
but if you can't get up to full speed within your structure's length, why not do away with the tube entirely?
Because an evacuated tube is needed to negate the effects of friction at lower altitudes, otherwise you gain nothing by using maglev, as opposed to chemical propulsion.
but it's non trivial to accelerate beyond certain speeds using maglev style propulsion.
The research here has already been done, with proposals for a transatlantic evacuated tube containing a maglev train. Its really not practical, the cost is something fantastical, but it reaches something like 1/8 escape velocity at its top speed, if I recall correctly. And designs do not call for dedicated nuclear plants to power it.
If you're not reaching orbital velocity without independant thrust, you don't need the evacuated tube.
Well as far as I can see, you are reaching orbital velocity, at a 5 gee acceleration. And with this system, its much cheaper to launch, requiring only SSTOs and enabling a far higher payload. As an added benefit, if you want to launch robotic missions (like most of the ones over the last 30 years), just ramp up the juice and escape velcoity there you go!
Serious research starts with a sanity check on what you've already got. Why are you attacking the people doing just that? I didn't say this couldn't be done... Just that it wasn't really a "current technology" kind of project.
I never let sanity get in the way of a good idea. I doubt the wright brothers did either when they built their flying-tent-crossed-with-shopping-cart. Anyway, my apologies if you felt I was attacking you, I opened up this idea to the community hoping to hear both positive and negative reactions, but I just had a skirmish with a rather nasty poster and I was feeling a bit raw. Your opinions and ideas are more than welcome! As for current technology, I stick to my guns when I say we can do this right now, and the benefits would be overwhelming.
Zero gee mining, heres a notion. Its like eating a half ton of cheese; you can't fit your mouth around it. So you cut it up into smaller segments, with cheesewire. So lets take say a rectangular frame of adjustable size (from a few hundred meters to many kilometers), power it with solar power, even a satellite ring of solar reflectors which it deploys when it reaches its target. These power lasers or some kind of diamond saw arrangement going from one side of the framework to the other, which slice the asteroid up. That doesn't resolve your problems, however, since now you have slices of asteroid falling all over the shop.
So when a laser passes through a segment of rock, foam of a sticky sort gets pumped in behind it (I don't think this exists right now, but its not impossible, I am sure) to keep the bits stuck together. Then, just keep cross sectioning the rock until you have manageable bits, which can be broken off. Then the third part of the ensemble comes into play.
The refinery, nearby, would be fed chunks of asteroid, and superheat them to seperate components. Not having gravity, a massive centrifuge (centriforge?) would be needed to seperate the parts into their elements. Split up, cooled, and shaped, these ingots of asteroidy goodness could then be shipped back to a manufactory in orbit, or processed on the spot (unlikely given the complexity of the components to be designed, circuit boards, ceramics, the lot). Even bare rock could be used as nutrients for algae pods.
Since we don't know whats out there, I can't begin to say which components could possibly be manufactured in space, and which would need earth based supplies, at least at first. Once we have a vast stream or streams of ore sailing back towards earth, dozens of these rigs slicing up rocks, and more being built, the sky is indeed the limit. Also another factor is that cutting up even one decent sized asteroid might take years, so it might be better just to slice off bits from it, maybe encase it in some kind of foam or resin first for stability.
Yes, I thought something was amiss, and I barely understood the equation, heheh. I have been thinking about the fact that its relatively easy to insert something into GEO with this system (and very very cheap, comparitively speaking). It would be an idea to build components for further exploration up there, since its far easier to escape the earth's gravity well from GEO than from the surface, especially if you can move a few thousand tons of components up there every day. Not to mention that if you combine this system with a chemical propellant (much less than would be needed for the shuttle, for example), you could go pretty much anywhere you liked.
Also, I discussed building it laying down with Carlton Meyer, the skyramp guy. Apparently almost all of it would have to be vertical or you're dealing with some serious forces that we really don't have the engineering to handle right now.
If you had read my response, you would have realised that the evacuation is a non-issue. And the acceleration is not unfeasable, just incredibly bad for the health. The more people I talk to, the more realisation I have that the acceleration is a serious issue. However it appears now that this system is very useful for getting people and equipment into geosynchronous orbit, at a miniscule fraction of the current cost, and en masse. And keep in mind that this is without chemical rocket assistance. If you add even a small amonut of extra thrust (nowhere near what the shuttle uses) you can go just about anywhere you like. But orbit is sufficient for now. Once there, the rest of my suggestions could easily be put into play. Its a whole lot easier to get from orbit to escape than it is to get from ground to escape, especially when you can shuttle up components at a rate of a few thousand tons a day.
:D
One way or the other I have gotten some wildly variant responses in terms of the acceleration required and its effects, which tell me that a lot of people really have no idea. Also its worth mentioning that this system would effectively shelve any space elevator ambitions for the forseeable future, so I am getting a lot of flak from that crowd. Some serious research shall be done.
Just doing a "back of the envelope" calculation and an understanding of raw structural engineering, I fail to see how you can get a tube up that high.
Did you even read the links? Your back of the envelope calculations are inkorrekt, baby. They were designing mile high skyscrapers back in the 30's. The rest of your post rather falls into place from there.
space elevator as well, which is equally exotic but at least has some significant more engineering which has gone into the design and development of such systems.
Okay, I didn't want to have to do this, but I suppose it was inevitable. Equally exotic? Are you mad? We do not have now, or are ever likely to have, the kind of materials required for a space elevator. We don't even know if they are physically possible. Like impossible in the same way as super-relativistic speeds are impossible. I remember one poster in a previous discussion pointing out that it was like time travelling sneakers. Shoelace tying functionality, 100%. Rubber sole attachment, check. Time travelling, still working on it. I'll tell you what, read the links I supplied, then you can return and spout whatever you like. Until such time as you do, you have no right to be contributing to this discussion.
So an 11km launch tube, going at 5 gees, gets us almost 8% of escape velocity. And you're telling me that a tube 1232km long is needed for full escape velocity? Methinks I need to hire an actual physicist for a couple of days to get the facts here, cos a whole lotta numbers ain't adding up. :D
Okay, I was breaking it down into much smaller units, not dealing with the entire launch, sort of like changing speed from 10,000m/s to 10,001m/s over a space of 1m. Obviously as the speed gets higher the time to effect this change gets much much smaller, over the 1m distance. So the problem is the cumulative application of energy? Changing from 10,000m/s to 10,001m/s over 1m, whether it takes 1 second or .00001 seconds, is still just a change of 1m/s. Okay, I see the point here.
Right now I'm thinking of either a taller tower and / or chemical propellant after it pops out the top. One poster above suggested that at 5 gees, it would be enough to reach geostationary orbit, so it still offers massive advantages over anything we have now, especially in terms of cost per launch and time to launch. Twenty or thirty km high? Hmmm...
I think I'll post this again in a later discussion, I was a bit late to the party this time around. If it pans out anyway well, I'll go ahead and set up a feasability study with some investors, I reckon.
Well I know of a certain oil sheik or two that are trying to diversify their portfolio... ;)
Wait something is fishy here. 2 seconds to traverse the launch tube is wildly out there. Even to accelerate to 30m/s would take a lot longer than that. What you are looking at with this system is a slower initial acceleration, and then power being applied every meter (perhaps in increasing amounts) via a maglev system (one or more rails). So the time taken to cross each 1m second becomes shorter and shorter, but the actual speed increase (in terms of pressure) stays the same. Its not like a cannon blast. And how do cars reach 27m/s in 3 or 4 seconds? I think your numbers are a little off, there.
Where t is...? Time?
Yes indeed, I was fascinated by the idea of "ironbergs" in the Peter F. Hamilton neutronium alchemist series, basically they infuse an iron asteroid with nitrogen or something and it airbrakes down to terminal velocity when it lands. I have no idea how feasable that really is though.
.2 C, any pilot could pop a hole in one side of the earth and pop out the other. Well maybe not, but certainly annihilate civilisation as we know it. Tricky times ahead, one way or the other.
The global destruction end of things will definetely lead to some creative defence technology as well. I mean when you think about it, if we can build spaceships weighing a half million tons and capable of doing
I haven't read your links yet, but I'm skeptical about this being "readily achievable with today's technology."
:D
Well you might have a look at the links before you go shooting down the structural engineering end of things. As far as I can see, its very doable. The point of the top being 11 km in the air is that it sticks out above the troposphere, so burying it 11km underground or undersea defeates the purpose. Thats 11km above sea level. Anyone popping out at escape velocity into dense atmosphere is going to have a lousy afternoon. In the links they are talking about a standard chemical launch from the top; I'm talking about using that height to gain speed. And the discussions cover towers hundreds of kilometers tall, its fascinating stuff.
you've got to pump air out faster than it flows in the open top, or add the mass of a cover to the top
Yes, so you put an iris airlock at the top, and just keep it evacuated. Whatever air gets in (not at sea level air pressures of course, much much less) you just pump out of the airlock between launches.
I also went ahead and did some quick math. 1 m/s/s acceleration over 11 km is not enough:
Okay I'm not an engineer or a physicist, so I was a bit fuzzy on this whole area here. I was working it from 1m per second acceleration every single meter traversed (based on distance not time elapsed), bringing you to 11,000m/s when you pop out the top; am I completely off base in that? Assuming I am, how much taller would the tower need to be built to get escape velocity, or would adding chemical propellants once it is clear of the tower have much effect? Certainly much, much less propellant would be required in the latter case than is currently needed, I think.
requires 2.4 MW of power, not accounting for losses, which is one capability we do easily have
Yes, thats where the nuclear power station(s) I mentioned come in, 40mwe to 2000mwe for a normal plant. Financially very doable as well, as these things go.
It's a pity, because all of these ideas show some measure of original thought and are theoretically feasible in some fashion, but the technical challenges are rather mind-numbing.
Not a bit, they are all doable with what we have today. The scale may be somewhat grandiose, but what should be looked at are the potential returns, which I outlined in the original post there. I'm not out to discredit the space elevator idea, if it ever works I'll be happier than anyone, but I just don't see it working anytime soon. We can build the tower right now!
Thank you for your comments by the way, I don't know a lot about this field, but I'm trying to build up a theoretical model, and criticism is good!
Happily, this system produces 1/3 to 1/4 the acceleration of an average car.
:D
Its not FTL but baby will it get the ball rolling. I'll just run this by everyone here... With all the talk lately about a space elevator, I got to thinking after a sort of recent slashdot discussion, just what advantages would a space elevator offer over a tower launch? I contacted the man responsible for a similar idea, the skyramp (warning: hideous javascript menu may break firefox), Carlton Meyer, and had a dialogue in which he pointed me to a tower launch archive.
The ideas I see bandied about there are similar to what I had in mind, which would be essentially an 11km tall tower (think pylons rather than skyscrapers, based at sea), with evacuated airless launch tubes, using nuclear reactors to power a maglev or pulley system to accelerate vessels to escape velocity. These would then emerge above the end of the troposphere, with it's associated weather and air pressure, and have little to no fuel needed to escape the earth's gravity, meaning you could do a lot more while you were up there. At 1m/s acceleration, you would be at escape velocity when you exit the top of the tower.
Not only would this enable multiple launches daily, it is, unlike the space elevator, readily achievable with today's technology, and financially viable as well. Given NASA had an annual budget of $16.2 billion for 2005, and a nuclear power plant costs a cool billion to build, give or take, we could have this up and running in a few years. And once we are up there...
Space has got vast, essentially unlimited resources. One recent story pointed out the trillion dollar iron asteroid up there. The thing has about 5 tons of steel for every man, woman and child on earth. And thats just one of god knows how many... billions more?
Once we leap the cost to escape hurdle (as I think I have managed), we can proceed to use these resources. There are several obstacles in the way of this, first of which is zero gee mining, we have no idea how to do it. We can either mine the ore out there, or bring the asteroid back into orbit and slice it up there. Or slice it up and send it back to orbit. I would be opposed to moving it back into orbit for processing, purely for the debris issue. Perhaps a lunar base would have some merit there.
So we set up a mining and processing operation either on the moon or in deep orbit, and start cutting and processing one of those bad boys. Whats the first thing we build? A bigger processing and mining operation. Space exploration, much like the internet, has to be a largely incestuous affair at first, existing solely for its own benefit.
Once we have that mastered, we can move to algae pods in orbit for food production, oxygen refining, and fuel production (biodiesel or chemical engines), all of which can be powered by the immense energy of the sun, and use the raw materials abundantly available in space. Whether you ship that stuff back to earth or use it for further colonisation, its a vital step.
The production of automated scouts is also a high priority; a vast amount of surveyor and prospector drones to sweep and map every square inch of every rock and gas in the system, out to the Oort cloud, and figure out what they are made of. I'd err on the side of quantity rather than quality, still no reason not to have either. This could be combined with deep space observatories that would make hubble look like the end of a coke bottle.
So now we have a manufacturing bridgehead, a good idea of what's interesting out there, and a cheap means to launch to orbit. Actual manned system ships would come next, to either colonise or investigate the system. The rest, as they say, is (future) history.
A lot of this would require automatio
Well coward, that works out at 10m x 10m for every man, woman and child, or about 25m by 25m for every family of five. You can't fit in that, coward, you really are justifying the fat ass american cliche. Keep sucking down those cheeseburgers, baby.
Sorry, but its true.
Disruptive change never comes about via the masses.
What masses. Masses are composed of people, individual units. Le Bon's contagion theory of mass psychology has been fairly comprehensively disproven, to my satisfaction at least. There is no group mind. Just because they are not assembled in a mob at this exact moment in time does not make them any more or less susceptible to crowd psychology (Turner and Killian's diffuse crowds), as in this case, the internet. Even marketing, the art of influencing the masses and crowd psychology, is ultimately targeted at the lowest common denominator; a scattershot approach designed to attract individuals, as many as possible.
it would appear that smart people are on the rise.
Smart, stupid. Such a vast amount depends on the environment that one's genetic makeup rarely has anything but a passing influence on comparitive intelligence. Sorry for that, eugenics, back to the drawing board, I'm afraid.
In the overpopulation of our planet
The planet is so far from overpopulated its not even funny. You could quite comfortably fit the entire population of the planet in the state of Texas, and I don't mean three high, I mean a house and land each. The perception of overpopulation is a misconception.
try convincing billions that you are right!
If you are right, you are right. The opinion of billions does not make you less so. Sooner or later they will have to come to accept your point of view. Draw your conclusions, base your future actions on that, and move on.
Communism would have been a massively disruptive change (on paper), but once it was implemented, people were able to smash it back down into the monarchy they were accustomed to
People didn't smash it anywhere. A few individuals did, taking advantage of a poorly educated, impoverished, and frankly terrified population. I have tremendous faith in humanity and its ability to ultimately rectify its own shortcomings. Denigrating the teeming masses really isn't helping anything. Anyway communism was a fundamentally flawed social theory. Marx sadly did not think it through to its logical conclusion. What he did manage to do was sully the waters sufficiently that any even vaguely similar system can immediately be branded "communism" by those with a lot to lose in such a system. Indeed, any system outside the current one.
Do you really envision slavering mobs of semi intelligent buffons marauding up and down the countryside, crushing new ideas anywhere they go?
Ah, yes, Pubmed: the home of 20 years of total hogwash stored in one compleat archive. Right up there with the UC San Francisco Pharmacy School as the world's leading research center into ignorant and racist thought.
...blah blah blah... world.
Yes, highly skilled in both anthropology and history there too. Or wait, no. Don't get me wrong, I have no quarrel with their findings, which I am sure are accurate, or as much as they can be, which given the state of medicine generally, ain't that much. However you would not be the first to take good(?) science and turn it to a sly dig.
"His incorrect conclusions"? You're an outstanding poster child for someone who is willing to disregard peer-reviewed research
See above for details. Pharmacology does not an accurate picture of history make.
I would reference my European History textbook, but it doesn't have the advantage of being online like Wikipedia does.
European history textbook, hmmm... no, I've never heard of this hallowed tome. And I did European History.
I'm ethnically almost half Irish and have an Irish last name
Sigh. Just out of interest, rather than the many points I could raise here, why don't I just ask how one can be "almost half Irish". Was there surgery involved? Having been born and raised in Ireland, ethnically all Irish, and being able to trace my roots back a thousand years, I'm still calling bullshit on your argument. I might know, having been born and raised here and all. 0% my arse.
Find a reference to prove me wrong
You're the one asserting that the people of the republic of Ireland are alcohol dependants, and have been for thousands of years. The burden of proof lies with you.
It's always fun Europeans learn a little bit about their own history from Americans.
Indeed it is. That day, however, is not today.
Kind of weird, but if this shapes up to have a 70% mortality rate, then it is what will be needed to survive. Not just for personal self, but also for our children.
What exactly do you mean by this? You are aware that the entire worlds population could fit very comfortably in an area the size of Texas? I don't mean piled three high, I mean a house and land each. You aren't one of these people that think the population needs "weeding out"?
If you ever did work at the CDC, I sincerely hope they fired your ass long, long ago.
Maybe agarwal should have studied the effects of extended alcohol consupmtion on people before wobbling to his incorrect conclusions then. Still, you do seem to have a lot of research to back you up there, its understandable if you swallowed it whole.
Ah yes, the wikipedia, even more reliable sources of information. I can't be bothered to look up the article now, but I recall reading one worthy had written up an article about how european men had smaller willies than american men. Truly a rock of reliability. As for vitriol, sufficient unto the day, the evil thereof. I have learned a few things however, probably not what you think, though.
The January/2006 Wired had an article titled "How Click Fraud Could Swallow the Internet"
Just a point of interest here, the only thing click fraud is going to swallow is google. The rest of the internet will get by just fine. Honestly the only types of online advertising I would pay for would be fixed fee (and I'd only try that for a short period to see results) or affiliate advertising, where clicks are attributed to referrers and tracked directly to sales. When sales are made, the referrer gets a commission.
Honestly google should have their heads examined, basing their whole business model on pay per click. This settlement will be the first of many, mark my words.
which would greatly increase the chances of contracting disease.
Nah given even basic statistical gradients, your assumptions are wildly inaccurate. Wildly. Perhaps you should keep your outrage in check until you finish understanding what is written.
Are you saying all Irishmen are hot headed maniacs who fly off the handle at the least provocation? RaARAaaARRRR (head asplode)(joke).
Neal Stephenson
The world reknowned anthropologist and history professor. Oh wait he's not. Try do a little better next time you quote your dependable sources. Hint: sci fi writers don't count.
Source. On both counts. You could just as easily be blowing shit now as before.
as a result a total innability to drink alcohol would have quickly resulted in death.
Wow. Did you just say that anyone that couldn't drink alcohol in Europe would have died during the middle ages? This displays an ignorance so profound it defies belief, both of European history and of what happens to people who drink alcohol continuously. There were various extended periods during Irish history that the general population couldn't afford to eat, never mind afford to drink alcoholic beverages. Thats why the population is smaller now than it was in the 1840s. And have you ever met anyone that has replaced all of their liquid intake with beer and/or other spirits? I sincerely doubt you have, because they generally don't survive longer than a few months, if that.
And having travelled and lived in many parts of asia, I can tell you that alcohol intake is just as prevalent (and has been historically) as in the west. Slightly less so, but not enough to make a difference. So basically your post is just as much bullshit as the other guys.
Pull nonsense figures out of your arse, get called on it.