hm.. I'm not sure what to think of what Kerry has said yet.
Posted by mr_porteiro_head (Member # 4644) on :
I am a Bush supporter, but I agree with Kerry on this subject. The stuff Bush has done has done nothing but hurt NASA, and I doubt any good will ever come out of it.
Posted by Dagonee (Member # 5818) on :
I'm goint to invade your thread with some remotely on-topic questions. You said you picked up this month's Discover. How realistic was the space elevator article?
The whole idea seems far-fetched to me. I guess the possibility for using it to launch ships is because they overcome gravity without losing the centrifugal motion? But doesn't that mean the cable has to be able to support all the weight on it?
A ship launched this way would still need a very powerful engine to slow down, right?
Dagonee
Posted by mr_porteiro_head (Member # 4644) on :
I haven't read the article, but I'll comment on space elevators.
No, a space elevator doesn't have to support all of its weight. Imagine that a space elevator is a rock tied to the end of a *very* long string. The earth, with it's rotation, is spinning that string and rock around once per day. If the string is long enough, then the centrifugal effect will start to counter-act gravity. If you make it too long, then the string will be pulling against the earth in the opposite direction of gravity. If you make it just the right length, then there will be no up or down force on the elevator -- gravity and the centrifugal effect will balance each other out.
Posted by Noemon (Member # 1115) on :
Funny you should ask, Dagonee--I was just getting ready to start a thread about it. We can just use this one though.
For those who are interested, here is the article Dag is talking about.
I'll give you my thoughts on it in a second.
Posted by mr_porteiro_head (Member # 4644) on :
I couldn't find the article there -- just a short introduction to the article. Posted by Noemon (Member # 1115) on :
I was much more excited by the idea of building a space elevator before I thought about the issues that ssywak raised in this thread.
By the way, I had the wrong link on Discover.com. The actual article can be found here. The piece I linked to was kind of an introduction to the article itself.
Oh, hell! Even that is just a teaser! Apparently you have to be a Discover subscriber, and I just bought this issue on the newsstand. Sorry folks.
Anyway, about space elevators: I still think that they're a really good idea, and worth pursuing. I don't think that we have all the answers yet as to how to build one, but the technology seems promising enough that it's worth finding a way to overcome obstacles like those that Steve details in my link above.
Posted by Dagonee (Member # 5818) on :
quote:No, a space elevator doesn't have to support all of its weight. Imagine that a space elevator is a rock tied to the end of a *very* long string. The earth, with it's rotation, is spinning that string and rock around once per day. If the string is long enough, then the centrifugal effect will start to counter-act gravity. If you make it too long, then the string will be pulling against the earth in the opposite direction of gravity. If you make it just the right length, then there will be no up or down force on the elevator -- gravity and the centrifugal effect will balance each other out.
But when you spin something around fast, doesn't it put stress on the string in an outward direction?
I'm having a hard time imagining it just "hanging" there, I guess.
What would happen if it snapped? Would things on the end go flying off at whatever the rotational speed is for something at 22,000? If so, that suggests there's a lot of stress on the tether.
The materials described in the article are cool, though - stronger than steel but so light and thin they waft down like newspaper if they fall.
Dagonee
Posted by mr_porteiro_head (Member # 4644) on :
Yes, if it's long enough, it puts stress in the oposite direction.
And it couldn't just "hang there" -- if it just hung there, the earth would spin underneath it. There would be a lot of horizontal forces where it connects to the earth. But if it were balanced correctly, there would be no vertical forces.
If it were balanced like this -- what would happen if it snapped? It depends on where it snapped. If it snapped right at the base, then it wouldn't float off. But if it snapped in the middle, then the oughtward part wouldn't weigh enough to stay balanced, and it would fly off. The closer part wouldn't have the centrifugal effect to counter-balance gravity, and it would crash to the earth.
[ June 17, 2004, 02:00 PM: Message edited by: mr_porteiro_head ]
Posted by eslaine (Member # 5433) on :
quote: What would happen if it snapped? Would things on the end go flying off at whatever the rotational speed is for something at 22,000? If so, that suggests there's a lot of stress on the tether.
Depending on the materials, this could be worse than a cometary impact! A carbon fiber cable, whipping around the planet at the equator, impacting at near orbital velocity.
I don't need to do the math for this crowd.
Posted by mr_porteiro_head (Member # 4644) on :
You are right. Things would get interesting *very* quick.
Posted by naledge (Member # 392) on :
I have to agree with Kerry's view on this matter. While Bush's initiative provides a definite direction for American space exploration, the timelines and funding this administration is proposing for this venture grossly underestimates the true costs.
-nal
Posted by advice for robots (Member # 2544) on :
I wonder if Kerry will ever not be critical of anything Bush does. It's almost a knee-jerk reaction.
Posted by Kwea (Member # 2199) on :
Except that he has a point, and his point agrees with just about every person qualified to actually do the science...
Haven't you heard what the NASA scientists think of his plan and the estimated costs?
Kwea
[ June 17, 2004, 08:17 PM: Message edited by: Kwea ]
Posted by ArCHeR (Member # 6616) on :
Maybe it's because Bush NEVER cares about if his budgeting works, as long as what he does makes him look good. People are just going to have to realize that Bush doesn't care about people besides his rich friends, his family, and maybe Texas.
About the space elevator: Impossible to build. You can only buid up so high, and you can only build down so much, and the distance between those two is too great. maybe if the bottem were built to record heights, and the top were built entirely in zero G, then lowered down into place using a lot of rockets to counter gravity and keep it at geo-sync orbit...
It would just have to be a MASSIVE engineering feat. It would be the greatest thing man has ever built to say the least.
Posted by Zamphyr (Member # 6213) on :
meh, Kerry didn't really say anything that spectacular. It basically boils down to, "I like what NASA's been doing, I'll try not to cut funding." Nothing I'm getting too excited about.
Whereas the President has basically said, "NASA, you've gone nowhere since I was a kid. Stop research. Go to Mars."
I can't say I whole-heartedly support either side. President Bush has done nothing for NASA in his first term; recent comments seem to be nothing more than campaign promises. I remember Bill Clinton doing the same thing at about the same time eight years ago.
The current President seems to have a strong aversion to basic science. I hate that. About the only thing I really can get behind is his (sofar) loose suggestion that the government should set goals and let the private sector try to reach them, ala federally backed X-prize type contracts/contests.
Posted by plaid (Member # 2393) on :
Red Mars by Kim Stanley Robinson has space elevators. His scientists use nanobots to build it.
S P O I L E R
... and there's a scene where the space elevator gets sabotaged. The folks at the top go plunging off towards Saturn. The cable itself falls towards Mars and wipes out everyone within, what, 100 miles of the path of the cable...
Posted by advice for robots (Member # 2544) on :
Oh, heck, Kerry's probably right, but it is the nature of election year for the opposing candidates to cry wolf so many time that the fact that Kerry actually has a valid point in criticizing Bush is lost in the many times that it's all just spin. And vice-versa, of course.
As long as Bush is making the original proposals and Kerry is just seizing on things to critique, Kerry comes off as a comedian who just builds a bit on everyone else's material to get laughs. And vice-versa.
Sorry I got hung up on that. Posted by ArCHeR (Member # 6616) on :
They way I see it, Kerry is saying, "Bush, you're right. We need to go back to the moon, and go to Mars. But you're a moron, and you're not giving NASA what they need to do it."
Oh yeah, and just my little plug to support Kerry: He has a plan for the economy that is actually logical, and despite what the GOP wants you to think, doesn't raise taxes (only resets the top 1%'s taxes so that we can pay for things), and Bush's plan is to do the same thing he's been doing [sarcasm] because it's working so well [/sarcasm].
Posted by Dagonee (Member # 5818) on :
quote:People are just going to have to realize that Bush doesn't care about people besides his rich friends, his family, and maybe Texas.
Posted by Kwea (Member # 2199) on :
I don't like Bush...big suprise there...
But I wouldn't say he doesn't care about others. As long as the are "christian". And support his war.
Posted by Dagonee (Member # 5818) on :
More .
Posted by ArCHeR (Member # 6616) on :
You roll your eyes, and yet it's the truth. Don't you see that?
Posted by fugu13 (Member # 2859) on :
Care . . . is an interesting word. Is it enough to say one cares? Does it count if one "really feels it big time" but doesn't act on it in a meaningful way? Is it possible to really feel it big time and not act in a meaningful way?
For instance, does Bush care about education based on teh NCLB act? Perhaps. I'm somewhat undecided, but would like to abstract out a smidge, from particular acts to the people behind the DOE. Rod Paige. Rod Paige was superintendent of the extremely "successful" public school system in Houston.
Houston's school system has been exposed as a bed of incompetence and corruption. Paige either knew what was going on and is criminally corrupt, or didn't know and is insufferably incompetent. Schools were reporting completely insane numbers to the superintendent's office on people voluntarily leaving school, for instance. Any educator that glanced at those numbers would know something highly unusual was going on.
Rod Paige should not be secretary of education. He is not qualified for the job, either morally or technically, depending as above. That he still has the job says something about the Bush administration, and how much Bush "cares" for education.
[ June 18, 2004, 10:46 AM: Message edited by: fugu13 ]
Posted by Mike (Member # 55) on :
On the elevator issue...
Yes, the technology isn't there yet. But it is neither as far-fetched nor as dangerous as it seems. I read the article when I got the magazine a few weeks ago, so this is from memory, but:
First, the biggest stumbling block technology-wise is developing a cable that is strong enough to support its own mass (plus the additional overhead mass required to make the thing functional). Carbon nanotubes are plenty strong enough, but so far we haven't been able to build them into a material in high enough concentrations. We'll need to increase the strength of current attempts by about two orders of magnitude, which is a lot. I'm guessing we'll get there eventually, but it'll take at least 20 years.
Second, they have thought of everything. They launch a coiled ribbon into geosynchronous orbit, then begin to unroll it both upwards and downwards, keeping the center of gravity of the entire thing at 22,000 miles. They've designed a sort of relay system that will catch the lower end of the ribbon and fix it to a platform in the Pacific. The base of the cable will be thicker and less wide so that hurricanes won't affect it much. They will place a thin layer of platinum or some such non-reactive metal over the area of the ribbon that passes through the ozone layer to prevent corrosion. They will perform constant repairs to protect against damage from spacejunk.
Third, if it snaps: yes, we'll lose the far end and whatever/whoever is attached to it. (Though, not necessarily, since most of what's up there will be close to a true orbit, so could detach and be recovered later.) The lower end probably wouldn't cause any damage at all: all but the bottom 50 to 100 miles of the ribbon would burn up in the atmosphere, and since the ribbon is extremely light (I think the figure was something ridiculously small like a few pounds per mile) the rest would float down and land in the ocean.
So we won't see this for a while, but it is not impossible. And not any more dangerous than the space shuttle. And it makes it easy and cheap to get things into orbit.
(Again, if I got any of the details wrong, this is from memory. Sue me.)
Now back to your regularly scheduled Kerry-Bush wrangling.
Posted by Dagonee (Member # 5818) on :
quote:You roll your eyes, and yet it's the truth. Don't you see that?
Apparently caring can only be done in Archer-approved ways, is that it?
Dagonee
Posted by ArCHeR (Member # 6616) on :
Let's see. Bush said a tax cut would help the economy. It didn't. Why? Probably because most of the tax cut went to the uber wealthy.
Bush wants to support the no child left behind act? Then why isn't he funding it? I thought someone who cared about education would fund their plans to help it (by the way, even fully funded NCLB doesn't work anyway due to the very nature of the program).
And I'm sure he really cares about human life. That's why he's pro-life and pro-death at the same time! Amazing, isn't it?
Posted by Dagonee (Member # 5818) on :
quote:Let's see. Bush said a tax cut would help the economy. It didn't. Why? Probably because most of the tax cut went to the uber wealthy.
Incorrect - it did help the economy.
quote:Bush wants to support the no child left behind act? Then why isn't he funding it? I thought someone who cared about education would fund their plans to help it (by the way, even fully funded NCLB doesn't work anyway due to the very nature of the program).
Read one liberals take on it. It’s not fully endorsing of the plan, but it acknowledges the good points: Giving 'No Child' a Chance.
quote:And I'm sure he really cares about human life. That's why he's pro-life and pro-death at the same time! Amazing, isn't it?
You are either A) incapable of making subtle philosophical distinctions between innocent lives and those of duly convicted murderers or B) deliberately mischaracterizing the President’s position. Which is it?
Dagonee
Posted by ArCHeR (Member # 6616) on :
Correction: it didn't help the economy in any signifigant way, and nowhere near as much as was promised.
And conviction has nothing to do with the death penalty being wrong. Or don't you remember that Jesus was condemned by HIS peers?
Posted by Dagonee (Member # 5818) on :
It helped a lot.
And no where does it say civil authorities can't punish people for crimes.
Dagonee
Posted by fugu13 (Member # 2859) on :
Oh, much of the tax cut so far has helped the economy (though some of its been silly). Its just that most of the tax cuts haven't been implemented. The ones that have already gone through were supported by the democrats as well when enacted.
Giving credit to Bush for most of the tax cuts that have happened so far is giving undue credit, these tax cuts were almost all obvious and needed. The capital gains tax is the only one I'm willing to give his administration kudos for before anyone else, the rest they don't deserve any particular congratulations for.
It's the yet to take effect tax cuts that Greenspan and O'Neill have been horrified about.
[ June 18, 2004, 11:29 PM: Message edited by: fugu13 ]
Posted by ArCHeR (Member # 6616) on :
So you're saying the jews had the right to punish Jesus for heresy?
It's better to have a guilty man get life, than an innocent man death. That's why I'm against the death penalty. Or have you not heard of all those cases where men were put to death, only to have DNA evidence reveal their innocence after they're already burried?
And doesn't it make sense for true Christians to be against the death penalty, even if the accused is guilty? Let him live as long as possible somewhere where he's not a danger, and perhaps one day he'll find God.
It's better that a righteous man die early and reach the father sooner, than an unrighteous man to die before he can repent.
And on the tax cuts: The aren't anywhere as good as they were promised to be, and they're also regressive, which is unfair. I believe they could have been much more effective if the lower and middle class got, say, the tax cut from the top 1% divided amoung them...
Posted by Mabus (Member # 6320) on :
quote:So you're saying the jews had the right to punish Jesus for heresy?
Actually, the charge was blasphemy. But yes, if the charge had been accurate, Jesus should have been executed.
quote:It's better to have a guilty man get life, than an innocent man death. That's why I'm against the death penalty. Or have you not heard of all those cases where men were put to death, only to have DNA evidence reveal their innocence after they're already burried?
I hear this all the time, and I always point out--when I can stand to repeat myself so often--that having criminals run loose harms a lot more people than the occasional mistaken execution. It's tragic, but the alternative is worse.
quote:And doesn't it make sense for true Christians to be against the death penalty, even if the accused is guilty? Let him live as long as possible somewhere where he's not a danger, and perhaps one day he'll find God.
It's better that a righteous man die early and reach the father sooner, than an unrighteous man to die before he can repent.
A lot depends on what doctrine you believe here. Suffice it to say that just because you're innocent of a particular crime doesn't make you righteous overall.
Posted by Ron Lambert (Member # 2872) on :
Send Kerry to Mars. He'd like it on the red planet. He could sit on Olympus Mons (the highest mountain in the solar system) and look down on everyone.
Posted by TomDavidson (Member # 124) on :
"It's tragic, but the alternative is worse."
No, it's not. You can prove this to yourself by taking the argument to its logical extreme on either end:
In one case, criminals are never arrested and punished. In the other case, everyone is arrested and punished. I submit that the latter case is worse.
But even if you don't want to go the absurdem route, consider that being so zealous in prosecution of the guilty that the innocent are indiscriminately punished is pretty much the definition of institutional evil.
Posted by kerinin (Member # 4860) on :
quote:having criminals run loose harms a lot more people than the occasional mistaken execution
yeah, that's a great sentiment; too bad it conflicts whith the whole basis of our legal system. innocent until proven guilty, equal in the eyes of the law, etc etc. no real need for that, let's just start our own gestapo eh? and besides, most of those "mistaken executions" are probably poor black guys, not need for us to worry right?
Posted by ArCHeR (Member # 6616) on :
I never said let them go! The criminals wouldn't be running loose. I'm saying don't kill them. Pay attention. And you just proved what's wrong with pro-death penalty. You said that if he was guilty, he should have been executed. They thought he was guilty, he wasn't, but was killed anyway. That's why it shouldn't be the death penalty.
Posted by Dagonee (Member # 5818) on :
He's supporting the death penalty in the context of our criminal justice system, not one without "innocent until proven guilty, equal in the eyes of the law, etc etc."
Really, why did you feel the need to bring race into it. Are you incapable of discussing this without calling people Nazis and racists?
Dagonee
Posted by Mabus (Member # 6320) on :
quote:In one case, criminals are never arrested and punished. In the other case, everyone is arrested and punished. I submit that the latter case is worse.
I think that's rather more extreme than is really warranted by the argument. The difference is between some innocent people being executed versus some guilty people continuing to kill, steal, rape, or what have you. I freely admit that we as a society are responsible for the former; I simply believe we're equally responsible for the latter. When the guilty are not properly punished, we bear a sizable measure of the guilt for their subsequent crimes.
quote:But even if you don't want to go the absurdem route, consider that being so zealous in prosecution of the guilty that the innocent are indiscriminately punished is pretty much the definition of institutional evil.
It's not about being "indiscriminate". It's about inevitable error and how many false negatives (leading to the potential for further crime that harms the innocent) are worth a false positive (that harms the innocent directly).
quote: yeah, that's a great sentiment; too bad it conflicts whith the whole basis of our legal system. innocent until proven guilty, equal in the eyes of the law, etc etc. no real need for that, let's just start our own gestapo eh? and besides, most of those "mistaken executions" are probably poor black guys, not need for us to worry right?
And how exactly does it do that? All I've said is that there is a danger to the public from criminals that we fail to convict, and that we as a society are just as responsible for that danger as we are for accidental executions of the wrong person. Therefore we need to take better action to prevent that kind of error, and that there is an inevitable tradeoff between the two kinds of error. I don't see how that means we must assume people are guilty rather than innocent or any such thing. It just means that we need to consider the results of our inaction just as we consider the results of our action.
quote:I never said let them go! The criminals wouldn't be running loose. I'm saying don't kill them. Pay attention.
Inevitably, some of them will be running loose, Archer. Some will be inappropriately freed at trial. Some will be paroled and return to crime. Some may escape. Some will commit violent crimes in prison. The death penalty should be reserved for the most serious cases, but it should be an option for those who pose the most danger to society.
quote: And you just proved what's wrong with pro-death penalty. You said that if he was guilty, he should have been executed. They thought he was guilty, he wasn't, but was killed anyway. That's why it shouldn't be the death penalty.
Let's go over this again--I said he should have been executed if he were guilty. That he was not guilty should have been blatantly obvious. This is not a circumstance in which accidental error makes sense. But where there is real possibility for error, it can go either way--and either type of error hurts people.
I don't understand why this is so difficult to understand. When someone is sentenced too lightly and does more harm as a result, we are just as responsible for that as when someone innocent is declared guilty.
Posted by Dan_raven (Member # 3383) on :
My problem with the President Bush Nasa plan is the same as my problem with the Bush Tax cut and the Bush Hyrdrogen Car push and the Bush--well, everything.
He sets out a plan, underfunds it, and makes allowances for the dirty work, the real funding of it, to occur somewhere in the future, after he has left office (even if he is reelected.). In this way he gets credit for creating these wonderful plans, but when they get shot down for being unbudgetable, he is out of the picture and someone else has to take the blame for being the "bean counter."
"We go to Mars" he says. Budget will be available 2010. "We we ride on Hydrogen" he says. Budget will be available 2020. "We cut taxes now, but they go back up in 8 years so the overall 10 year budget is not too unbalanced." This gets approved by even the fiscal conservatives. Then he turns around and calls anyone looking to actually keep to HIS budget plan (and allow the tax cuts to end to help balance the budget) a evil tax raising liberal.
I begin to think that Bush's plan for Iraq was to do a cheap invasion, and minimal rebuilding, and save the big costs of reconstruction for future presidents to worry about. This is where his plans fell apart.
Posted by ssywak (Member # 807) on :
As early as January 16th, on this forum:
quote:Oh, and a brief rejoinder to all those discussing Space Elevators in this thread:
What are you, nuts?
The NY Times had an article on this nonsense as recently as September 23, 2003 (I know--it's hanging up on the wall outside my cubicle at work). I've also read the "Popular Science" articles about it. I don't think that Scientific American has stooped to the level where they'll actually report on it (though I am probably wrong).
Problems:
NY Times--The Space elevator is specifically refered to as a "Ribbon ... about 3 feet wide and thinner than a piece of paper" and about 22,300 miles long. Has anyone here ever taken a blade of grass between their thumbs andmade a whistle out of it? This is a very long whistle. Two more concepts: Von Karmen Vortices, and flutter.
Popular Science: I don't have that article in front of me, but it amounted to, "as soon as we can develop the material to make such a plan work, we can start building it." Same goes for transparent aluminum, by the way. In other words, that's an incredibly big "if." We can also move from star-to-star easily, as soon as we develop an appropriate means of transportation.
Either way, even if the elevator column is hundreds of feet wide, it's still tens-of-thousands of miles long! You'll get fluttering instabilities regardless. For the first 50 miles, you'll have to deal with massive and variable wind effects. For the next few hundred miles you'll have to deal with space debris.
On, and for the first few miles, you'll have to deal with terrorists trying to fly planes into it.
And nobody has apparently given any thought as to just how you anchor the damn thing into the Earth.
Here's another pretty picture: the line snaps 12,000 miles up. What happens? I imagine the outer component starts moving towards geo-synchronous orbit, but takes up some god-awful high-energy rotation and winds up in a lower orbit, whipping incessantly and tying itself into knots. The lower section is driven by wind forces at its base, as well as gravity gradients along its length, and ACTS AS A GIANT BULL-WHIP AS IT WRAPS ITSELF AROUND HALF THE EARTH'S EQUATOR.
I do so wish you people would take some time and think these things through.
--Steve
PS--Don't get me wrong, though; I think that research in these areas is great, and will lead to some wonderful and helpful stuff. But if you're going to paint the big "Space Elevator" picture, you're going to have to look at all the other details as well. You can't just look at the benefits, and ignore the hurdles.
I really don't think that anything has changed.
And re. Bush's BS support for the Mission to Mars: Didn't Congress just turn down (a few months ago) pretty much any necessary budget increases required to start support of such a mission program?
I can't remember the phrase...is Bush blowing smoke out of his ass, or up ours?
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