The problem with predictions on costs, its that you have no idea how much the cable will cost, and hence estimated costs are literally just made up. There is simple no way to know what the cable will cost.
As for disruptive technology. Not really. Not nearly as disruptive as CNT bulk materials with +60GPa strength with a density at ~3000 kg/m3. This is so much better than what we have today that is like jumping from the copper age to the post industrial age in one go, with respect to materials anyway. Lets not forget CNT very different thermal conductivities and other properties. It would/will be a big deal.
However such a material is so useful in so many different ways, that we don't need a space elevator as a reason to research it.
This is how i see it happening. First we finally get bulk CNT with +60GPa strength, but they are expensive(try buying 1kg of SWCNT today). However the weight savings and hence fuel savings for aircraft make them worth every penny. The weight savings for rockets are even bigger, and launch costs drop significantly now is easy to make STO RLV. With cheaper access to LEO the number of launches increases.. this keeps going till the price of CNT bulk material comes down enough (there is now more demand from other markets) that a elevator starts to make sense. You now have the demand and volume to space that it could work--economically--and you have a cheaper materiel (which is only getting cheaper). Things keep going from there. Note that there was little disruption in this case due to the high initial cost of the fibers.
But even if the fibers are really cheap. Then it is *cheaper* to make rockets too, and fuel is cheap. This is left out of economic analysis from space elevator proponents. They assume the break trough can only be used for the elevator and leave launch costs of rockets where they are without the break trough.
We could build a railway bridge across the ocean. It would a lot more capacity compared to airports. But we don't. Because its just not economic. This is like that, in more ways than one. Airports are flexible with the routes they fly, while you have to make a bridge point to point. A space elevator is the same. Its useless for LEO access, and you still need rockets if you want to go anywhere where but ~GEO.
There is a difference between "asked to change the name" and a cease and desist. It is like the difference between asking nicely and being a rude bastard.
I have got all my jobs after my PhD from people i meet at conferences. I didn't kiss arse, i was "me" both with respect to the social activities and the professional talks/work. I know my field so when i meet people I generally know what they have done, otherwise i just ask and we talk "shop". It is not hard to work out who will be a good boss and who will not, if what they work on is interesting or not. Also they quickly work out if you are going to be a good post doc or not.
Now when you apply for a position you are not just a name on a pile. It really makes a big difference.
But what kind of robotic lab can I get with the mass budget needed for several humans+life support. Such a lab does not need to return, does not get sick from radiation effects etc. Also if it does die, this is still 100x more politically tenable and a human. However we can go much smaller and still get a lot done, probably cheaper than sample return. Since i can always send a follow on lab after i have some results and this would still be cheaper than sample return.
It would be cheaper to devlop and send such a robotic lab that would be capable of a huge amount of science.
And the strategic value for Humankind of being able to reach one planet apart from Earth is immense.
Well start with a list already. Getting men on the moon was a waste of money, they would have got better science out of the money by using even 1960s robotics. Today robotics is even better. So what "immense" strategic value do we get from single human mission that does many many times less than the 100s of robotic missions that could have been sent instead?
What "immense" value do I get when the people send die before they get there?
One way trips don't preserve anything. There is no reason to send people, there is nothing that people can do on the surface that robots can't (you can make and send a *lot* of robotic missions for the price of one human mission). The argument that we should do because all these people will get jobs is a broken window fallacy... You only have to look at the pork being held over from the shuttle program to see that a bulk of NASA "missions" is nothing but government welfare for engineers.
60 is enough for carbon since the density is about 2000-3000kg m^-3. However its not a given that bulk cable will have even close to that strength. All materials have a bulk strength much lower than the "theoretical bond strength". Basically you are fighting entropy. A few mm of fiber without defects is easy. A few meters is harder, 50,000km.... good luck. There is already one paper that suggested that bulk CNT will not do the job since defects can "slip" just like in metals (more complex in CNT however).
If you can get a bulk cable that is strong enough, you still have some very big obstacles. One that you just never see addressed is the massive amounts of energy that are stored in the strained fibers. At 63GPa, even 1mm of strain is 63MJ per m^2. When a micro meteorite hits some fibers that energy got to go somewhere, there is very real possibility that you just can't make "rip stop" CNT cable.
However as I said before. The biggest obstacle IMO is economic. Once you have 63GPa CNT bulk material, you can make rockets out of it, with pretty magical weight ratios. Or even launch loops or whatever. Its not a given that a space elevator will be the best investment.
This is not correct. Cosmic rays have high energy and are not stopped so easily. Indeed they have so much energy that they produce massive secondary showers of high energy particles.
How long you are in space depends what you need to worry about. Long duration, cosmic rays becomes the lions share of the dose. Shorter missions the solar wind is more of a issue (IIRC). In both cases CME are a real problem--without a "bunker" shelter, your dead. The shielding requirements means that you just can't do small without pretty high doses compared to what we would endure here on earth.
We have materials with tensile strength in the GPa range. Some very high strength steels even have that (~2GPa) and glass fiber does as well. Some carbon fiber is up in the 3-5GPa region. However a space elevator needs strength to weight *ratio* (steel is poor while carbon fiber is the best so far). Almost the whole structure is supporting itself.
There is no material in existence that's strong enough for a space elevator. Sure there are some *theoretical* possibilities, but that's all they are, *theory*.
And even if we do eventually make a material with that kind of strength to weight ratio (ie more that 10x current best). It will be easy to make uber performance rockets.
A space elevator is like a bridge across the ocean. Even if you could build it. Its still cheaper to have a runway at each end and fly, than to build the bridge.
Gift tax, Fringe benefit tax etc... all came up as folks worked out ways *around* taxes, by either paying folks with fringe benefits rather than salary or just giving them a "gift" every now and then.
I do mostly agree. However at least for music there are places like jamendo. I have found some good stuff lately and its not garage band quality recordings either. Like TenPenny Joke...
Nine tenths of the law is enforcement. The choice to not enforce the law for your "buddies" is perfectly legal. A DA can and does choose who and who not to charge with a crime. This principal can be applied at any level.
Proton Anti-proton annihilation does not result in gamma rays. Protons are made out of quarks, so you get more interesting results. The primary products are on average an even split of all 3 Pions, +, - and 0. The 0 decays almost immediately to gammas, and there goes 1/3 of your energy. However these are high energy gammas and will deposit there energy in a fairly short range in dense (ie higher than air) medium, and still quite confined in air (ie miles). The + and - Pions have quite a long life time (2.6e-8 s mean life time) and are traveling almost at the speed of light. They can travel many meters in free space. However since they are charged they dump there energy into matter very quickly. Heating the sounding mass to insane temperatures. Finally the changed Pions decay into muons and neutrinos.
Now you have a ball of matter heated to millions even billions of degrees. This emits massive amounts of x rays which then heats a even bigger ball of matter. It should be noted in conventional nukes, the initial hot ball of plasma heats a larger ball of matter via x rays. This "secondary" ball of heated material expands creating the destructive shockwave.
It would be very easy to ensure rapid mixing of matter and antimatter. There are many instabilities that aid the mixing.
Note that as with conventional nukes, they do rely on dumping energy into surrounding matter. In a vacuum like in space, the effects are very different and pretty much attenuated compared to "surface work".
Theoretically you could make a hydrogen bomb powerful enough to be a "crust buster" at the least. You just need a *lot* of lithium and Deuterium, and a pretty big fission trigger or triggers, or even a hydrogen bomb trigger.
But the biggest deployed H bomb by the US was 25Mt yield and weighed less than 10tonns IIRC. So by a lot, I don't really mean a lot compared to the size of the planet. In fact 25 tonns of LiD can produce a bomb of over 1 GTon (1000Mt) and would be a cube 3 meters on each side. You still need a trigger, hohlraum and tamper. This is too small to be a true doomsday device. But you get the idea. If you hide it in a warehouse, say 30x10x10, you are a 100x more powerful and need 2700tons of LiD--so we getting up to a 1000Gt yield.....
Your forgetting that we really are talking about a *single* proton (~1GeV of rest mass) or even a million protons, its nothing compared to us. All the antimatter ever produced in the history of mankind is not enough energy to light a light bulb for more than a few minutes. We are around high energy events like this all the time from background radiation, especially if you live in Denver or spend a lot of time at the top of mountains or in airliners.
For this level of instrumentation, there are no economies of scale. Its why good optics are expensive even for terrestrial applications and with lots of competition. making stuff accurate to +-50nm or so over a large area is expensive.
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Do you seriously think that some people don't have more than one account? Modding is many things. Reliable and objective it is not.
The problem with predictions on costs, its that you have no idea how much the cable will cost, and hence estimated costs are literally just made up. There is simple no way to know what the cable will cost.
As for disruptive technology. Not really. Not nearly as disruptive as CNT bulk materials with +60GPa strength with a density at ~3000 kg/m3. This is so much better than what we have today that is like jumping from the copper age to the post industrial age in one go, with respect to materials anyway. Lets not forget CNT very different thermal conductivities and other properties. It would/will be a big deal.
However such a material is so useful in so many different ways, that we don't need a space elevator as a reason to research it.
This is how i see it happening. First we finally get bulk CNT with +60GPa strength, but they are expensive(try buying 1kg of SWCNT today). However the weight savings and hence fuel savings for aircraft make them worth every penny. The weight savings for rockets are even bigger, and launch costs drop significantly now is easy to make STO RLV. With cheaper access to LEO the number of launches increases.. this keeps going till the price of CNT bulk material comes down enough (there is now more demand from other markets) that a elevator starts to make sense. You now have the demand and volume to space that it could work--economically--and you have a cheaper materiel (which is only getting cheaper). Things keep going from there. Note that there was little disruption in this case due to the high initial cost of the fibers.
But even if the fibers are really cheap. Then it is *cheaper* to make rockets too, and fuel is cheap. This is left out of economic analysis from space elevator proponents. They assume the break trough can only be used for the elevator and leave launch costs of rockets where they are without the break trough.
We could build a railway bridge across the ocean. It would a lot more capacity compared to airports. But we don't. Because its just not economic. This is like that, in more ways than one. Airports are flexible with the routes they fly, while you have to make a bridge point to point. A space elevator is the same. Its useless for LEO access, and you still need rockets if you want to go anywhere where but ~GEO.
There is a difference between "asked to change the name" and a cease and desist. It is like the difference between asking nicely and being a rude bastard.
No, the G. Lucas estate has already taken all possible forms of overrated.
I have got all my jobs after my PhD from people i meet at conferences. I didn't kiss arse, i was "me" both with respect to the social activities and the professional talks/work. I know my field so when i meet people I generally know what they have done, otherwise i just ask and we talk "shop". It is not hard to work out who will be a good boss and who will not, if what they work on is interesting or not. Also they quickly work out if you are going to be a good post doc or not.
Now when you apply for a position you are not just a name on a pile. It really makes a big difference.
But why do we need G.O.D.? And if we don't need G.O.D. we don't need HARLIE.
But what kind of robotic lab can I get with the mass budget needed for several humans+life support. Such a lab does not need to return, does not get sick from radiation effects etc. Also if it does die, this is still 100x more politically tenable and a human. However we can go much smaller and still get a lot done, probably cheaper than sample return. Since i can always send a follow on lab after i have some results and this would still be cheaper than sample return.
It would be cheaper to devlop and send such a robotic lab that would be capable of a huge amount of science.
And the strategic value for Humankind of being able to reach one planet apart from Earth is immense.
Well start with a list already. Getting men on the moon was a waste of money, they would have got better science out of the money by using even 1960s robotics. Today robotics is even better. So what "immense" strategic value do we get from single human mission that does many many times less than the 100s of robotic missions that could have been sent instead?
What "immense" value do I get when the people send die before they get there?
One way trips don't preserve anything. There is no reason to send people, there is nothing that people can do on the surface that robots can't (you can make and send a *lot* of robotic missions for the price of one human mission). The argument that we should do because all these people will get jobs is a broken window fallacy... You only have to look at the pork being held over from the shuttle program to see that a bulk of NASA "missions" is nothing but government welfare for engineers.
I have even donated to some of the artists...
Its at .01ppm or about 10000x less than commercial U ore. It is 100x easier to make it here. Even today without fusion.
Learn how to tell a joke.
60 is enough for carbon since the density is about 2000-3000kg m^-3. However its not a given that bulk cable will have even close to that strength. All materials have a bulk strength much lower than the "theoretical bond strength". Basically you are fighting entropy. A few mm of fiber without defects is easy. A few meters is harder, 50,000km.... good luck. There is already one paper that suggested that bulk CNT will not do the job since defects can "slip" just like in metals (more complex in CNT however).
If you can get a bulk cable that is strong enough, you still have some very big obstacles. One that you just never see addressed is the massive amounts of energy that are stored in the strained fibers. At 63GPa, even 1mm of strain is 63MJ per m^2. When a micro meteorite hits some fibers that energy got to go somewhere, there is very real possibility that you just can't make "rip stop" CNT cable.
However as I said before. The biggest obstacle IMO is economic. Once you have 63GPa CNT bulk material, you can make rockets out of it, with pretty magical weight ratios. Or even launch loops or whatever. Its not a given that a space elevator will be the best investment.
This is not correct. Cosmic rays have high energy and are not stopped so easily. Indeed they have so much energy that they produce massive secondary showers of high energy particles.
How long you are in space depends what you need to worry about. Long duration, cosmic rays becomes the lions share of the dose. Shorter missions the solar wind is more of a issue (IIRC). In both cases CME are a real problem--without a "bunker" shelter, your dead. The shielding requirements means that you just can't do small without pretty high doses compared to what we would endure here on earth.
We have materials with tensile strength in the GPa range. Some very high strength steels even have that (~2GPa) and glass fiber does as well. Some carbon fiber is up in the 3-5GPa region. However a space elevator needs strength to weight *ratio* (steel is poor while carbon fiber is the best so far). Almost the whole structure is supporting itself.
There is no material in existence that's strong enough for a space elevator. Sure there are some *theoretical* possibilities, but that's all they are, *theory*.
And even if we do eventually make a material with that kind of strength to weight ratio (ie more that 10x current best). It will be easy to make uber performance rockets.
A space elevator is like a bridge across the ocean. Even if you could build it. Its still cheaper to have a runway at each end and fly, than to build the bridge.
Gift tax, Fringe benefit tax etc... all came up as folks worked out ways *around* taxes, by either paying folks with fringe benefits rather than salary or just giving them a "gift" every now and then.
Imagine if you had to pay IP rights on every piece of technology you buy.
We already do. But here is some irony, Hollywood was set up in California because it was lax with patents, in particular Thomas Edison patents.
The government is worse than the private sector for everything has truthiness. What do you need data or facts for?
I do mostly agree. However at least for music there are places like jamendo. I have found some good stuff lately and its not garage band quality recordings either. Like TenPenny Joke ...
Nine tenths of the law is enforcement. The choice to not enforce the law for your "buddies" is perfectly legal. A DA can and does choose who and who not to charge with a crime. This principal can be applied at any level.
Proton Anti-proton annihilation does not result in gamma rays. Protons are made out of quarks, so you get more interesting results. The primary products are on average an even split of all 3 Pions, +, - and 0. The 0 decays almost immediately to gammas, and there goes 1/3 of your energy. However these are high energy gammas and will deposit there energy in a fairly short range in dense (ie higher than air) medium, and still quite confined in air (ie miles). The + and - Pions have quite a long life time (2.6e-8 s mean life time) and are traveling almost at the speed of light. They can travel many meters in free space. However since they are charged they dump there energy into matter very quickly. Heating the sounding mass to insane temperatures. Finally the changed Pions decay into muons and neutrinos.
Now you have a ball of matter heated to millions even billions of degrees. This emits massive amounts of x rays which then heats a even bigger ball of matter. It should be noted in conventional nukes, the initial hot ball of plasma heats a larger ball of matter via x rays. This "secondary" ball of heated material expands creating the destructive shockwave.
It would be very easy to ensure rapid mixing of matter and antimatter. There are many instabilities that aid the mixing.
Note that as with conventional nukes, they do rely on dumping energy into surrounding matter. In a vacuum like in space, the effects are very different and pretty much attenuated compared to "surface work".
Theoretically you could make a hydrogen bomb powerful enough to be a "crust buster" at the least. You just need a *lot* of lithium and Deuterium, and a pretty big fission trigger or triggers, or even a hydrogen bomb trigger.
But the biggest deployed H bomb by the US was 25Mt yield and weighed less than 10tonns IIRC. So by a lot, I don't really mean a lot compared to the size of the planet. In fact 25 tonns of LiD can produce a bomb of over 1 GTon (1000Mt) and would be a cube 3 meters on each side. You still need a trigger, hohlraum and tamper. This is too small to be a true doomsday device. But you get the idea. If you hide it in a warehouse, say 30x10x10, you are a 100x more powerful and need 2700tons of LiD--so we getting up to a 1000Gt yield.....
Your forgetting that we really are talking about a *single* proton (~1GeV of rest mass) or even a million protons, its nothing compared to us. All the antimatter ever produced in the history of mankind is not enough energy to light a light bulb for more than a few minutes. We are around high energy events like this all the time from background radiation, especially if you live in Denver or spend a lot of time at the top of mountains or in airliners.
For this level of instrumentation, there are no economies of scale. Its why good optics are expensive even for terrestrial applications and with lots of competition. making stuff accurate to +-50nm or so over a large area is expensive.