That one was very interesting - I was actually thinking of STS-37, which landed 600ft short of the runway at Edwards. (Of course, that is not in Utah - I got that one wrong, I was mixing up two missions.)
Basically, the weather people miss-predicted the winds at altitude. Fortunately, the Edwards runway has large under and overruns (its really just a big dry lake bed), so the Shuttle didn't break up. On a normal runway it would have been loss of orbiter, loss of crew.
It is interesting that this isn't mentioned in any official places - wouldn't it be better if NASA admitted to any and all mistakes? That way people would know that space is still dangerous. As it is, the public thinks that the shuttle is safe and boring - so they go ballistic when it fails. In reality, I think almost every mission has some failure.
To help you out here - most people agree that at least taking off from a runway doesn't make sense for large launches. Getting to orbit takes a LOT of energy, typically more than 7 times the mass of the ship in the highest energy mass density fuel available (hydrogen)! So, in order to lift off horizontally, you need wings that can carry all that mass at takeoff. It turns out the wings are too heavy if strong enough to support the fuel mass. It can be done with staging (leaving the wings behind), but then you need an amazingly huge aircraft, that can lift multiple thousands of tons!
Landing is debatable, though. Wings weigh more than a parachute, but add a LOT of capabilities. The common fight here is retro-rockets (seen as having safety issues) verses wings (heavier, and not quite as capable as retro-rockets). For real examples of the various problems, the DC-X landed hard and broke, the Space Shuttle landed short (and would have been destroyed anywhere but in the Utah desert).
Landing mass is very important, because it has to be lifted up, accelerated (using 7 times its mass in propellant), and decellerated (requires your shielding to handle more energy disipation).
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What two consenting adults people do between themselves is none of your concern
Agreed, and that has nothing to do with this issue. That is what I meant by keep listening, maybe those 100,000,000 people have something to say. And, by the way, in the only areas where we have actual data the percentage of people saying "no" to same sex marriages was higher than the number voting for Bush.
The real issue is not "should gays be given the same rights as hetros." Even the "evil" Bush says that they should. He says that the word marriage should be replaced by civil unions in laws, and that same-sex civil unions should be allowed.
The real issue is changing the word marriage to include something it didn't before. Lots of people have a real problem with that.
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I'm not upset at all about your opinion of the issues. I'm annoyed that people keep calling over half the population ignorant. If there are more than 100,000,000 ignorant people, you need to check your story on what is ignorant.
Besides, even if they are wrong - which in this case they may very well be - it is impolite and politically unwise (as in you will not get what you want) to call them "ignorant masses." Essentially, what you are saying is that you don't want a democracy, you want a dictator that agrees with your morals. Well, I want a dictator that agrees with my morals too, but that would be unpleasant for everyone except me...
This issue is not as simple as you think. Stop dismissing those that have concerns about it, and start listening to them. You don't have to agree, but if you want to be a responsible adult you must listen.
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Perhaps instead of calling them "ignorant masses" and ignoring their needs because they are different from yours and therefore unreasonable, you should try to console the "ignorant masses," and help them to realize their potential?
Liberals can be SO arrogant! If you decide a policy is right, and it causes half the entire country to rise up against you, can you at least entertain the possibilty that you were wrong?
The calculations are for a 0.1 meter wheel, which is admittedly small. The forces decrease as the wheel gets larger, but then the mass goes up. That is actually why I stated the force in Gs, because that way it scales pretty well with larger wheel sizes (larger wheels have lower force but are larger and so have more mass, so they basically have the same problem). I think 1000 km/hr is the asymptotic limit, and if you are operating in that regime, just use rockets - it will be cheaper.
The sheath (like paint to avoid oxidation) greatly increases the challenge, and that's pretty much what I'm pointing out. Not impossible, just unlikely to beat a carbon nanotube technology rocket in overall cost. Fuel is surprisingly cheap - fuel costs to orbit are around $10/pound. Airlines, which at a nantube technology level would be a pretty close analogy, run at about 1.5 times fuel costs. So the limit of rocket technology would go to $15/pound, or about $3,000 per person to orbit.
I'm just saying that beating this number using a large ribbon cable will be difficult.
As for the 100km/hr limit - top speeds will be several times this, presumably. But not an order of magnitude higher. An easy way to check the number is to design the connection point between the stationary cable and the elevator car. Connectionless doesn't work because the cable's properties cannot be changed (we are too close to the ultimate edge of the barely possible to make it magnetic, for example). So, you are really taking about a wheel on a ribbon. At 1000 km/hr, a 0.1 meter wheel will be turning at 28,000 RPM. The force required to keep the wheel from flying apart is about 30 billion Gs. So you can't even make the wheel from carbon nanotubes...
As I've said before, I think the real deal-breaker is the maintenance. Essentially, the Earth orbit environment is like a sandblaster. It will gradually eat through your cables. That means that you will need to replace the entire structure every few years - I think that will be too expensive.
That and the fact that the elevators will probably be slow. It is very hard to push on something next to you that is moving at high velocity next to you. At 100 km/hour (they are talking about a friction based drive mechanism), it would take 330 hours to get into orbit. And that limits your total throughput too much!
Some other interesting research that could factor in here is that Homosexuals are more likely in second children than in first. Biologically, that may make the first children more likely to prosper.
Just a nit - the 240,379 L version is a fuel transport version, with practically no cargo. It's not trivial engineering, and it may not be even practical, I'm just saying it's not meritless or impossible.
OK, I looked at your other posts and your not a troll, so...
You must have misunderstood me. I have no problem being a part of the solution, I just have a problem being called the problem. The terrorist hate me. The terrorists want to kill me, personally. They are not just going after the Romans, Greeks, Bush, etc because that group has attacked them. I am not doing anything to them, but because oil companies deal with Saudi Arabia (something not within my control) my life is in danger. The terrorists see my existance as the problem, when in reality they should see Isreal or Saudi Arabia (depending on who you talk to) as the problem. They can't sucessfully attack those targets, so instead they attack me so that my government will bring pressure on those targets.
I'm afraid I feel no connection whatsoever with the terrorists. They are a cancer of society. Cancers are lethal for the same reasons as terrorists, that the illness is not really treatable after the terrorists (or cancer) has spread. The only things that work at that point are too draconian to contemplate.
I think leaving the planet is a viable solution. All Iraqis, Iranians, Palestinians, etc that wish to come may come. But leave your hate at the door. Let those that remain tied to the Earth for religious and whatever other reasons die in the terrorist wars to come.
It may not seem viable now, but give me 10 years...
Technically, I knew that and just didn't think things though... I was thinking for some reason that Microsoft was reporting google searches as there own.
Kerosene (Pretend its Jet A) Energy per Liter: 33 MJ/L
Hydrogen (Liquid) Energy per Liter: 8 MJ/L
Assuming a 45% efficient jet turbine, and a 90% efficient fuel cell, the hydrogen fuel is about twice the volume of the kerosene fuel. That could be easily handled with a small modification of the plane's design.
As you say, making the fuel cells powerful enough to drive a 747's turbine would be tricky, to say the least...
It's just engineering, though! (Fuel cells produce electricity. Large electric motors are incredibly efficient, and so are electric fans.)
Good information, but in my opinion wrong conclusion (in the article). The amount of energy stored is set by the amount of energy needed. So the tank will store the same amount of energy whether it is gasoline or hydrogen. A hydrogen tank's fuel will weigh half as much but be twice as large (assuming fairly high compression). A gasoline tank will weigh more, and be smaller. Talking about energy density per unit mass and relating that to hazard level is pretty shaky. It is probably better to relate energy density per unit volume to hazard level, though as I say in general the total energy storage of a tank is is kept constant between fuel types (200 miles travel/tank of fuel, or in this case 1000 fillups=200,000 miles of travel/tank).
It all comes down to efficiency. A normal car gets maybe 10-15% of the energy of the fuel. A hydrogen car (using a fuel cell) gets 80-90% of the energy. Steam reforming oil to make hydrogen is 70-90% efficient. That means that oil-gas-car is 10-15% efficient, while oil-hydrogen-car is 56-81% efficient. Essentially, you use a LOT less oil (up to 1/8 normal usage) if you convert it to hydrogen frist. (ICE just cannot get to a fuel cell's efficiency)
The problem is that fuel cells are expensive. The hope is that they will be cheaper when mass produced.
The advantage is that if you use as fuel cell, energy retrieval can be 80-90% efficient. At that efficiency, the tank size goes back down to somewhat reasonable.
To be fair, they used the same technique for steam leaks on old battleships. It is the pressure, not the type of gas. Low pressure hydrogen is less likely to kill you than gasoline (because it won't stay on you while it burns, so you get to run away safely). Of course, it would be expensive to ship or store hydrogen low pressure, hence the problem.
It is true that hydrogen leaks are notoriously difficult to detect, however.
Where exactly can I go and be assured of not being attacked by pirates, unfriendly natives, or forced to obey to someone else's ideas of what "good" is?
In my opinion, any country I could go to has more problems than my own (that's why I haven't left permanently), and anywhere that is not a country is under threat of "bad" people, like pirates in asia and the south pacific.
Well, technically almost anything done in geosync is not going to make it to Earth. It is unlikely for anything to be put in an orbit intersecting Earth (an object thrown straight down from geo will not necessarily hit earth), and even if it did it would burn up in the atmosphere first (bad entry angle and all that). But what I was really saying is that anyone that wanted to could leave Earth, and so they don't have to worry about stuff falling on their heads.
People who stay on Earth are the people to whom the risk / benefit of staying on Earth is less than the cost of getting to orbit. (Of course with today's launch prices, that is everybody!)
Odd that you were marked as troll and flamebait. In general you are correct, except that (free will) colonists are normally middle class (because they can afford the ticket). They typically are trying to go from a situation they have no control over to a situation they have more control over. Quakers came to America for freedom of religion. Some Irish came over to avoid a famin. People talk about leaving the US to avoid Republican government, etc.
The real motivator I feel will be 2 fold. First, the threat of terrorism / poverty will drive people to leave Earth (which probably improves life for those left behind as well). Second, people will leave Earth to escape the mass of rules that all governments create. As any government ages, it comes up with lots of little rules of behaviour for every situation (for example, whenever someone dies or a shuttle blows up there is a new law created). These rules don't bother most people, but to some they troublesome. Those people will leave as well.
Just remember, the way to get rich during a colonist movement is to be a landowner, a shopkeeper, or a transportation system owner.
But even if they do that, it is better than what we have now. I don't have to be involved. And neither do, for example, the people in Iraq that really want peace - they could just leave in this instance. Right now, I cannot escape the fact that eventually a terrorist is going to make a crater out of a building near me. There is no reason I should be involved in a middle eastern problem that I personally had no (or at least very little) part in creating. Frankly, I could live well enough getting my energy elsewhere, but that isn't an option for me at this point.
As you say, space is big and if I don't want to be involved with a fight in the middle east (or as you say, over it) - I can just leave!
I am thinking more long term. There are problems to be solved on Mars (cold, sand storms, low energy availability, etc.), and (probably somewhat harder) problems to be solved in space (near perfect recycling of air and water, safety, artificial gravity that doesn't make you sick, etc.). My point is that if you solve the problems on Mars, you have less than doubled the space available for humans (or probability of our species survival, if you prefer). Mars colonization doesn't lead anywhere but Mars.
Once we have gone to space, our possibilities are limitless. For example, once completely self contained space platforms are common, one of them will almost certainly get fed up with everyone in the sol system - and take off for another star. It won't matter how far you are going, because the journey (or arrival) would not really change your life style any.
In addition, it will be possible to get with a group of like-minded people and build your own society. This could be an end of terrorism, maybe even an end of some of the other unlpeasant things that happen on Earth. (Not that this will change human nature, it will just reduce the struggle for resources.)
I don't think we should colonize another planet. Why waste all that energy getting out of this gravity well only to stick ourselves in another one? I think the future of humanity is to create and live in structures in solar orbit. All the problems can be solved through engineering, just like the Mars problems would have to be. And once we have figured it out, there are no limits on expansion, etc!
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That one was very interesting - I was actually thinking of STS-37, which landed 600ft short of the runway at Edwards. (Of course, that is not in Utah - I got that one wrong, I was mixing up two missions.)
Basically, the weather people miss-predicted the winds at altitude. Fortunately, the Edwards runway has large under and overruns (its really just a big dry lake bed), so the Shuttle didn't break up. On a normal runway it would have been loss of orbiter, loss of crew.
Best Link I can find
It is interesting that this isn't mentioned in any official places - wouldn't it be better if NASA admitted to any and all mistakes? That way people would know that space is still dangerous. As it is, the public thinks that the shuttle is safe and boring - so they go ballistic when it fails. In reality, I think almost every mission has some failure.
what do i know, im just a geek
To help you out here - most people agree that at least taking off from a runway doesn't make sense for large launches. Getting to orbit takes a LOT of energy, typically more than 7 times the mass of the ship in the highest energy mass density fuel available (hydrogen)! So, in order to lift off horizontally, you need wings that can carry all that mass at takeoff. It turns out the wings are too heavy if strong enough to support the fuel mass. It can be done with staging (leaving the wings behind), but then you need an amazingly huge aircraft, that can lift multiple thousands of tons!
Landing is debatable, though. Wings weigh more than a parachute, but add a LOT of capabilities. The common fight here is retro-rockets (seen as having safety issues) verses wings (heavier, and not quite as capable as retro-rockets). For real examples of the various problems, the DC-X landed hard and broke, the Space Shuttle landed short (and would have been destroyed anywhere but in the Utah desert).
Landing mass is very important, because it has to be lifted up, accelerated (using 7 times its mass in propellant), and decellerated (requires your shielding to handle more energy disipation).
What two consenting adults people do between themselves is none of your concern
Agreed, and that has nothing to do with this issue. That is what I meant by keep listening, maybe those 100,000,000 people have something to say. And, by the way, in the only areas where we have actual data the percentage of people saying "no" to same sex marriages was higher than the number voting for Bush.
The real issue is not "should gays be given the same rights as hetros." Even the "evil" Bush says that they should. He says that the word marriage should be replaced by civil unions in laws, and that same-sex civil unions should be allowed.
The real issue is changing the word marriage to include something it didn't before. Lots of people have a real problem with that.
I'm not upset at all about your opinion of the issues. I'm annoyed that people keep calling over half the population ignorant. If there are more than 100,000,000 ignorant people, you need to check your story on what is ignorant.
Besides, even if they are wrong - which in this case they may very well be - it is impolite and politically unwise (as in you will not get what you want) to call them "ignorant masses." Essentially, what you are saying is that you don't want a democracy, you want a dictator that agrees with your morals. Well, I want a dictator that agrees with my morals too, but that would be unpleasant for everyone except me...
This issue is not as simple as you think. Stop dismissing those that have concerns about it, and start listening to them. You don't have to agree, but if you want to be a responsible adult you must listen.
Perhaps instead of calling them "ignorant masses" and ignoring their needs because they are different from yours and therefore unreasonable, you should try to console the "ignorant masses," and help them to realize their potential?
Liberals can be SO arrogant! If you decide a policy is right, and it causes half the entire country to rise up against you, can you at least entertain the possibilty that you were wrong?
Sorry, that would be radius.
The calculations are for a 0.1 meter wheel, which is admittedly small. The forces decrease as the wheel gets larger, but then the mass goes up. That is actually why I stated the force in Gs, because that way it scales pretty well with larger wheel sizes (larger wheels have lower force but are larger and so have more mass, so they basically have the same problem). I think 1000 km/hr is the asymptotic limit, and if you are operating in that regime, just use rockets - it will be cheaper.
The sheath (like paint to avoid oxidation) greatly increases the challenge, and that's pretty much what I'm pointing out. Not impossible, just unlikely to beat a carbon nanotube technology rocket in overall cost. Fuel is surprisingly cheap - fuel costs to orbit are around $10/pound. Airlines, which at a nantube technology level would be a pretty close analogy, run at about 1.5 times fuel costs. So the limit of rocket technology would go to $15/pound, or about $3,000 per person to orbit.
I'm just saying that beating this number using a large ribbon cable will be difficult.
As for the 100km/hr limit - top speeds will be several times this, presumably. But not an order of magnitude higher. An easy way to check the number is to design the connection point between the stationary cable and the elevator car. Connectionless doesn't work because the cable's properties cannot be changed (we are too close to the ultimate edge of the barely possible to make it magnetic, for example). So, you are really taking about a wheel on a ribbon. At 1000 km/hr, a 0.1 meter wheel will be turning at 28,000 RPM. The force required to keep the wheel from flying apart is about 30 billion Gs. So you can't even make the wheel from carbon nanotubes...
As I've said before, I think the real deal-breaker is the maintenance. Essentially, the Earth orbit environment is like a sandblaster. It will gradually eat through your cables. That means that you will need to replace the entire structure every few years - I think that will be too expensive.
That and the fact that the elevators will probably be slow. It is very hard to push on something next to you that is moving at high velocity next to you. At 100 km/hour (they are talking about a friction based drive mechanism), it would take 330 hours to get into orbit. And that limits your total throughput too much!
Some other interesting research that could factor in here is that Homosexuals are more likely in second children than in first. Biologically, that may make the first children more likely to prosper.
Just a nit - the 240,379 L version is a fuel transport version, with practically no cargo. It's not trivial engineering, and it may not be even practical, I'm just saying it's not meritless or impossible.
OK, I looked at your other posts and your not a troll, so...
You must have misunderstood me. I have no problem being a part of the solution, I just have a problem being called the problem. The terrorist hate me. The terrorists want to kill me, personally. They are not just going after the Romans, Greeks, Bush, etc because that group has attacked them. I am not doing anything to them, but because oil companies deal with Saudi Arabia (something not within my control) my life is in danger. The terrorists see my existance as the problem, when in reality they should see Isreal or Saudi Arabia (depending on who you talk to) as the problem. They can't sucessfully attack those targets, so instead they attack me so that my government will bring pressure on those targets.
I'm afraid I feel no connection whatsoever with the terrorists. They are a cancer of society. Cancers are lethal for the same reasons as terrorists, that the illness is not really treatable after the terrorists (or cancer) has spread. The only things that work at that point are too draconian to contemplate.
I think leaving the planet is a viable solution. All Iraqis, Iranians, Palestinians, etc that wish to come may come. But leave your hate at the door. Let those that remain tied to the Earth for religious and whatever other reasons die in the terrorist wars to come.
It may not seem viable now, but give me 10 years...
Technically, I knew that and just didn't think things though... I was thinking for some reason that Microsoft was reporting google searches as there own.
To beat this horse even further...
747 Maximum Fuel Load: 43,625 L
Kerosene (Pretend its Jet A) Energy per Liter: 33 MJ/L
Hydrogen (Liquid) Energy per Liter: 8 MJ/L
Assuming a 45% efficient jet turbine, and a 90% efficient fuel cell, the hydrogen fuel is about twice the volume of the kerosene fuel. That could be easily handled with a small modification of the plane's design.
As you say, making the fuel cells powerful enough to drive a 747's turbine would be tricky, to say the least...
It's just engineering, though! (Fuel cells produce electricity. Large electric motors are incredibly efficient, and so are electric fans.)
Even easier than that - type a random string (like SAGASDGXBJDFHZH) into msn, check the google search logs for that random string.
Good information, but in my opinion wrong conclusion (in the article). The amount of energy stored is set by the amount of energy needed. So the tank will store the same amount of energy whether it is gasoline or hydrogen. A hydrogen tank's fuel will weigh half as much but be twice as large (assuming fairly high compression). A gasoline tank will weigh more, and be smaller. Talking about energy density per unit mass and relating that to hazard level is pretty shaky. It is probably better to relate energy density per unit volume to hazard level, though as I say in general the total energy storage of a tank is is kept constant between fuel types (200 miles travel/tank of fuel, or in this case 1000 fillups=200,000 miles of travel/tank).
It all comes down to efficiency. A normal car gets maybe 10-15% of the energy of the fuel. A hydrogen car (using a fuel cell) gets 80-90% of the energy. Steam reforming oil to make hydrogen is 70-90% efficient. That means that oil-gas-car is 10-15% efficient, while oil-hydrogen-car is 56-81% efficient. Essentially, you use a LOT less oil (up to 1/8 normal usage) if you convert it to hydrogen frist. (ICE just cannot get to a fuel cell's efficiency)
The problem is that fuel cells are expensive. The hope is that they will be cheaper when mass produced.
The advantage is that if you use as fuel cell, energy retrieval can be 80-90% efficient. At that efficiency, the tank size goes back down to somewhat reasonable.
To be fair, they used the same technique for steam leaks on old battleships. It is the pressure, not the type of gas. Low pressure hydrogen is less likely to kill you than gasoline (because it won't stay on you while it burns, so you get to run away safely). Of course, it would be expensive to ship or store hydrogen low pressure, hence the problem.
It is true that hydrogen leaks are notoriously difficult to detect, however.
Where exactly can I go and be assured of not being attacked by pirates, unfriendly natives, or forced to obey to someone else's ideas of what "good" is?
In my opinion, any country I could go to has more problems than my own (that's why I haven't left permanently), and anywhere that is not a country is under threat of "bad" people, like pirates in asia and the south pacific.
Really, what are my options?
Well, technically almost anything done in geosync is not going to make it to Earth. It is unlikely for anything to be put in an orbit intersecting Earth (an object thrown straight down from geo will not necessarily hit earth), and even if it did it would burn up in the atmosphere first (bad entry angle and all that). But what I was really saying is that anyone that wanted to could leave Earth, and so they don't have to worry about stuff falling on their heads.
People who stay on Earth are the people to whom the risk / benefit of staying on Earth is less than the cost of getting to orbit. (Of course with today's launch prices, that is everybody!)
Odd that you were marked as troll and flamebait. In general you are correct, except that (free will) colonists are normally middle class (because they can afford the ticket). They typically are trying to go from a situation they have no control over to a situation they have more control over. Quakers came to America for freedom of religion. Some Irish came over to avoid a famin. People talk about leaving the US to avoid Republican government, etc.
The real motivator I feel will be 2 fold. First, the threat of terrorism / poverty will drive people to leave Earth (which probably improves life for those left behind as well). Second, people will leave Earth to escape the mass of rules that all governments create. As any government ages, it comes up with lots of little rules of behaviour for every situation (for example, whenever someone dies or a shuttle blows up there is a new law created). These rules don't bother most people, but to some they troublesome. Those people will leave as well.
Just remember, the way to get rich during a colonist movement is to be a landowner, a shopkeeper, or a transportation system owner.
But even if they do that, it is better than what we have now. I don't have to be involved. And neither do, for example, the people in Iraq that really want peace - they could just leave in this instance. Right now, I cannot escape the fact that eventually a terrorist is going to make a crater out of a building near me. There is no reason I should be involved in a middle eastern problem that I personally had no (or at least very little) part in creating. Frankly, I could live well enough getting my energy elsewhere, but that isn't an option for me at this point.
As you say, space is big and if I don't want to be involved with a fight in the middle east (or as you say, over it) - I can just leave!
I am thinking more long term. There are problems to be solved on Mars (cold, sand storms, low energy availability, etc.), and (probably somewhat harder) problems to be solved in space (near perfect recycling of air and water, safety, artificial gravity that doesn't make you sick, etc.). My point is that if you solve the problems on Mars, you have less than doubled the space available for humans (or probability of our species survival, if you prefer). Mars colonization doesn't lead anywhere but Mars.
Once we have gone to space, our possibilities are limitless. For example, once completely self contained space platforms are common, one of them will almost certainly get fed up with everyone in the sol system - and take off for another star. It won't matter how far you are going, because the journey (or arrival) would not really change your life style any.
In addition, it will be possible to get with a group of like-minded people and build your own society. This could be an end of terrorism, maybe even an end of some of the other unlpeasant things that happen on Earth. (Not that this will change human nature, it will just reduce the struggle for resources.)
I don't think we should colonize another planet. Why waste all that energy getting out of this gravity well only to stick ourselves in another one? I think the future of humanity is to create and live in structures in solar orbit. All the problems can be solved through engineering, just like the Mars problems would have to be. And once we have figured it out, there are no limits on expansion, etc!
Anybody with me?