Yes, but if you accept the fact that rescue missions will be impossible anyway, then it's a non-issue. Pretty much every astronaut who has ever gone up has accepted that fact. Even the astronauts on the ISS, in LEO have no realistic chance of rescue if something goes wrong and their escape Soyuz craft is unusable for some reason. No-one has a rescue rocket standing by to save them. Unless there happened to be a resupply mission coinciding with the disaster, they'd have to be able to wait months for rescue. On the moon? Forget it. So, for the time being, "abandoning it for safety reasons, medivac, or sending up emergency supplies/repair parts, etc" is no more viable a prospect on the moon than it is on Mars.
The gravity on the moon is half what it is on Mars. Mars has an atmosphere suitable for aerobraking and that actually provides a fair amount of radiation protection. It also may allow for lighter than air survey craft. The atmosphere also protects against micrometeorites, unlike the total vacuum of the moon. The atmosphere can also be processed to make methane and oxygen. Mars has a lot more water than the moon. It also has significant amounts of percholarates. The day is only fractionally longer than than that of Earth, making solar power practical, unlike the month long day on the moon.
Actual pluses for the moon include the fact that it has higher insolation than Mars, being closer to the sun. Of course, the month-long night kid of ruins that. The moon also requires marginally less power to reach than Mars, but since it takes less power to land on Mars since you can aerobrake, that's not really a factor. It matters when you're trying to lift off again, of course. You do need to spend longer in transit to Mars than to the moon, which increases the radiation exposure of the astronauts (though to perfectly acceptable levels with the right precautions). Don't give me the nonsense about the effects of isolation driving the astronauts crazy though. Pretty much every study ever done on it, along with the real world experience of the various space stations we've put up have put that one to bed.
Overall, Mars wins. It has much better prospects than the moon for the long term survival of a colony. People used to say that we should perfect colonizing the moon first, then move on to Mars, but Mars, despite not being closer, is safer and cheaper (marginally, but the more readily usable in situ resources take the win).
You can power a rocket launch with green renewable solar power. Just plug a solar power plant into a gas extraction/processing plant that sucks in air and produces liquid oxygen and methane. Then you use the liquid oxygen and methane to fuel your rocket.
Not that I think President Obama has been doing a particularly good job or that he's kept his campaign promises or anything like that, but I'm still astounded at the depths partisans will sink to in order to malign him. I mean, sticker shock at the pump is pretty harsh at the moment, but calling them "Obama levels" is disingenuous since they were this high, and higher, before he became President. It's sort of like when people blame the financial crisis on him and you're left sort of scratching your head. You can assume that those people just have short memories, but I remember people blaming him for the financial crisis within a week of him being elected (note: within a week of being elected, not within a week of taking office). That kind of magical thinking is just bizarre.
As for oil on Mars, importing it would be ridiculously expensive, but it could be useful as an in situ resource. It could be great for making rocket fuel for sending natural resources from Mars to Earth. If we could make everything (except maybe a few lightweight items like microchips) to manufacture rockets on Mars, then, from an Earth perspective, it actually would be financially viable to ship petroleum products to Earth from Mars. Of course, if the infrastructure on Mars ever gets that developed, then the resources would be more valuable in the local economy.
It took almost 90 years and a civil war for us to figure out that freedom applies to everyone or no-one. [wikipedia.org] Even those members of society we don't like.
The civil war ended in 1865. The US didn't give women, regardless of color, the right to vote until 1913. The civil rights movement didn't even gain real, national traction until the 1950's. The actual rights of the young are still a confusing mess.
No, not a cheque for the revenue generated. He's clearly entitled to from $750 to $150,000 per infringement. The award could then be reduced to $2,250 per infringement, just like for Jammie Thomas.
Believe me, that's certainly a concern too. It's just that it's not the _only_ concern. I just don't understand why people can only focus on one thing. The debate of the general public on air pollution (not that of experts, but the general public and the biased "experts" that polluting industries present are the ones that politicians listen to most) seems to focus only on climate change. The reality is that air pollution matters, climate change or not. To listen to some of the global warming "skeptics", if global warming isn't happening (or if it is, but it's not caused by humans, or if it is and it's caused by humans, but it's actually a great thing!!!) then all concerns about air pollution and dwindling fossil fuel supplies can just be thrown out of the window.
Why does this treat particulates as only a concern because they contribute to climate change? That's a potential problem, to be sure, but particulate emissions are a much more immediate environmental concern for those breathing them in. If the levels have been underestimated this much, that's a problem for people's health, especially along highways and in cities. Why does climate change have to be the be all and end all of all environmental impact discussions? Is it because it's so contentious and the ongoing feud drives page hits?
Yes, I know. Sorry my post was a wall of text, but if you'd read it you would see that I covered that. I'll explain it again and keep it briefer. As a car climbs the space elevator, it's velocity around the earth increases. Once it's about 2/3rds of the way to the altitude of geostationary orbit, it has achieved orbital velocity (for a lower orbit than the altitude it's at). Once it reaches geostationary orbit, it can hop off and stay in geostationary orbit, where the delta-v required to get anywhere in the solar system is drastically less than it is on Earth. The tether has to extend _past_ geostationary orbit, however. Beyond that point, anything dropping off the tether will be thrown into a higher orbit. Dropping off at around 50.96 km puts a payload into trans-lunar orbit. Dropping off around 53,100 km puts a payload at escape velocity. After that, you still need rocket propulsion for manoeuvring and braking/landing and so forth, but the vast majority of what you would have needed is eliminated.
You can look at any period of instability or injustice, in any region, at any time in history and ask "Why do they put up with [X]?". Whether it's warlords or just corrupt local politicians, or whatever the issue, it's easy to deride people for allowing the problem to persist. For the people on the ground it's not exactly as easy as you assume to fix things. Also, as far as warlords go (and warlords/bandits/etc. aren't the only problem, they were just the one you brought up that seemed to answer your own question), I think you may not understand how many warlords and their men actually consist of the "few good men" who put paid to the previous warlord, but then headed in the wrong direction, or are "good men" to one group and vile oppressors to another.
In the long run, people do things to improve the situation, and it does improve, then things can happen to set things back. Even if progress is steady in the right direction, it can take decades and decades and it's essentially a process of swimming upstream against all kinds of economic and political currents coming from the rest of the world.
You asked: "if they need a tractor, why in hell aren't they building their own tractors?", but then you wrote: "warlords wander large areas of Africa, raping and pillaging where they please. Instead of building dams, water purification plants, water distribution and sewage systems, they invest in guns, draft young children into their "armies", and do their very best to tear down the fragments of civilization that African enjoy."
The Earth's angular momentum is currently, through tidal interactions, moving the moons orbit out by about 3.8 cm a year. The moon masses about 7.36 × 10^22 kilograms and that's a change in velocity of about 5 * 10^-8 m/s. In terms of delta-v I suppose that's not a whole lot, but in terms of energy it's literally metric tons worth. The line stays up, rather than falling to Earth, in a hypothetical space elevator, because the counterweight is pulling away from Earth enough to counteract the weight of the cable. Take the elevator out to that point and drop off and you're not just going to stay in orbit at that point, you're going to fall away from Earth. Obviously, at that point, you're still going to need rockets for additional manoeuvring, but you're already essentially out of the reach of Earth's gravity.
There's still the question of what happens to the system when you drop something off the end of it like that. You put in energy climbing the tether, but that should have pulled the whole thing back towards Earth (it will if the system is designed so you can pull too hard and overcome the equilibrium of the system). So why can you keep putting payload after payload up it without it dropping down? The answer is that the energy comes from the Earth's angular momentum.
So, your objection is incorrect. Once the space elevator is up, it doesn't need delta-v to keep it up, or to fling payloads into higher orbits (which at that point pretty much means the entire solar system). Realistically, it probably will need rocket propulsion or solar sails, etc. to deal with 1001 equilibrium problems that will crop up. Super long tethers in space are going to be subject to all kinds of oscillations and weird effects we can't predict yet. Not to mention that we'll surely need to move the cable out of the way of space debris from time to time.
All this is kind of moot since the space elevator is still a pipe dream. It takes massive amounts of material in space to begin with and most of that material needs to be some kind of unobtanium that we don't even have a sound theoretical basis for yet. The best we have is that we haven't absolutely proven that a material that strong isn't possible yet. Even if we do find one strong enough, there's a ton of other physical requirements for it that it has to meet. The overall idea has some merit, but for the time being we should stick to ideas that we actually can build with real materials. Space elevators might be out, but skyhooks are a possibility. Also launch loops are a possibility. We might also be able to build short space elevators to low earth orbit orbital rings. An orbital ring would basically be a non-anchored version of a launch loop consisting of two tether loops rotating slightly faster than their orbits require, but in opposite directions. No mechanical system could touch the cables, but a magnetic system could, and a station could sit between them and have a tether of only 100 km or so descending into the atmosphere. Some materials like kevlar, fibreglass, and graphite fibre have breaking lengths sufficient for a space elevator that short. Once you actually have the payload in low earth orbit, you could then magnetically lock it to the orbital ring and accelerate the cargo along it until you release it. There are lots of other ideas for ways to make a tether system to space that can get around the problem of the breaking strength of the cable. For example, you can have a set of tethers on very complicated hybrid orbits that essentially play hopscotch with the earth and dynamically support a web of variable length cables that in turn support a space elevator to low earth orbit which then proceeds in longer and longer similarly supported sections until it gets to geostationary orbit.
Hopefully, we'll get advances in propulsion technology, or at least in the economics (it would be nice if we could get to the point where the materials and fuel of the rocket weren't negligible line items of the entire cost of launching) of rocket propulsion that will render i
That would be before 1783 then. Before then, human flight hadn't been achieved (on record, anyway) and was strictly in the realm of science fiction and mythology. So the only airspace anyone was likely to even consider is that reachable by an overhanging tree limb or part of a structure. Perhaps objects ballistically flung across the property might have been considered too. I highly doubt anyone at the time considered property rights to extend infinitely into the heavens.
Also, I believe I covered in the original criticism the fat that the borders of the property are in fact in motion with respect to the rest of the universe. I think I forgot to point out, probably because it's obvious, that you don't have to go out very far (about 4.3 billion kilometers depending on latitude, which is about ) before the borders are superluminal, making it physically impossible to actually locate anything inside the (infinite) majority of your property for any significant length of time.
That doesn't really answer my question of what counts as "over" your property though. There's very clearly a problem with that legal theory in that it doesn't define things very well geometrically. What kind of projection does the area "over" someone's property use. Is it a point projection from the center of the Earth that grows exponentially as it projects out into space, or not. To illustrate it better, imagine your property is perfectly circular. One projection is a cone with the point at the center of the earth and extending through your property so that the circumference of the cone touches the edge of your property and the other is a cylinder sitting on your property line and extending out into the universe parallel to a line that goes from the center of the earth and through your property.The first means that if your property borders another property, the border of your airspace borders theirs all the way out to infinity. The second means that the airspace borders diverge immediately and there's a tiny no-mans land between the two that grows at altitude.
This isn't meant to be 100% serious, it's just to illustrate how stupid the idea of projecting airspace indefinitely above someone's property is. The legal principle you're talking about doesn't actually take reality into account. It really only considers airspace on the scale of trees or buildings.
I'm curious about that airspace. Does it only extend to the top of the atmosphere, or all the way to the end of the universe? And does it operate as a projection from the center of the Earth outward so that at 2x the Earth's radius from your property straight up the horizontal cross-section of your property is 4x the area of your property on the ground and 16x the area at 3 Earth radii and so forth, or do the lines stay parallel to a line from the Earths center and through the exact geometric center of your property so that the cross-section is exactly the same area no matter how far away you are? I prefer the second option, because it leaves lanes that aircraft, or at least spacecraft can travel through as long as they're high enough. It's a bit unfair on people whose property is very, very large though because the area of the cross-section of their airspace is a less than their measured land area because of the curvature of the Earth. Plus, the second approach doesn't jibe with mineral rights because those must logically extend downward to a point at the center of the Earth, otherwise they would intersect everyone else's mineral rights. So, logically, airspace would extend the same pattern. I wonder how ownership of celestial bodies like the moon and the sun is handled. Temporarily owned by whoever's property cone it happens to be passing through at the time?
Or maybe airspace rights over property actually follow some sane principle? Up to a certain low altitude, for example?
The moons orbit is oblong, so you'd have to have some method by which the cable length could change. You need a cable strong enough to support its own weight. Gravity drops off as altitude increases by the formula g = 9.8 m/s^2(r/r+h)^2 (r is the radius of the earth and his your height), so it's 100% at the surface (very slightly less if you're at the equator), 96.937% 100 km up, 94.012% 200km up, 85.990% 500km up, 74.730% 1000 km up, 57.955% 2000 km up 37.770% 4000 km up, 19.678%. 8000 km up and so on. Even at geosynchronous orbit altitude (which may or may not be relevant depending on how this cable is being managed) where gravity is 2.287%, the average weight of the 35,800 km of cable to that point is about 15.172% of its Earth weight. Out at 325,000 km, which is about the distance of the L1 point between the Earth and the moon the gravity is.037% of what it is on Earth (not at the actual L1 point where it's cancelled by the moons gravity, this is just an approximation, not taking all forces into account) the average weight of the 325,000 km of cable is still about 1.932% of its Earth weight. So, if you need to stretch a tether out to Geosynchronous orbit, it needs to be strong enough to hold 15.172% of the Earth weight of 35,800 km of material. If the tether masses 1 kg per kilometer, that means it has to be strong enough, at that thickness, to hold the Earth equivalent of.15172*35,800=5431.576 kilograms. Tapering the tether can help, of course, but we still don't have any materials strong enough. For the L1 point, it's equivalent to holding 6279 kg on earth with that size cable.
Then there's the problem that the moon isn't in a geosynchronous orbit, so you can't tether the cable at a stationary point on earth. The poles aren't stationary, so the best you can do is anchor to tower, built on a train on a huge circular track around one of the poles.
Of course, the cable doesn't actually need to be a straight line to the moon. If you could make a tether to geosynchronous orbit, you could then have another tether from there to the moon. For that matter, you might be able to build a 60,000 mile tether that circles the earth at slightly greater than orbital speed (maintained by propellant brought up from earth on the space elevator) then attach multiple secondary tethers that loop around the earth towards the poles where they connect to smaller tether rings suspended above each pole with a station suspended in a web in the middle and a variable length tether that need only be a 100 km long or so (and could be supported by dirigibles through a good portion of the atmosphere) that tethers to a polar base station. You could take an elevator up at the pole, then down along one of the loops to the equatorial ring. From the equatorial ring, you could suspend another ring further out, or perhaps just spokes out to additional stations. From one of those, you could potentially even build a tether all the way to the moon and set it up on an orbit that jump ropes the Earth. Of course, the tether all the way to the moon would hardly be necessary. Once you're out to the orbital ring, if it's fast enough, you can just drop off and fall toward the moon, it would be a heck of a lot faster than pulling an elevator car along 400,000 kilometers of tether. At the moon end you could have another space elevator. The one at that end could use the same equatorial ring with polar elevator trick, but the moons smaller size and lower gravity mean that you could actually have a plain old space elevator right to the surface.
Of course, the above idea might have a lot of problems. Getting that giant orbital lasso trick to actually work might be next to impossible. Also, such a long tether going around the entire Earth is going to have to be carefully designed. It could run into some really interesting electrical effects that could instantly fry it. On the other hand, they could also be used as a method of powering the whole thing. In any case, it's a massive endeavour. You would have to start
I was thinking in terms of real humans rather than movie ones. I do remember the club he went to in the movie where they had lawyers on call to negotiate dating contracts and the ex-girlfriend and the robot sitting down for sandwiches in the desert at the end. Even in the movie universe though, those other girls presumably had real feelings and desires underneath all of the social constructs they were living within (maybe not the ex-girlfriend). The robot though, was pretty clearly just going through the motions without even any desires. It did the housework and put on a cheery face, brought him his slippers and a Martini or whatever and said that it loved him in an adoring voice a lot. Just a well-designed program. She was also easy in every sense of the word. No complaints, completely compliant, utterly selfless in every sense of the word (especially in the sense that she didn't have one). In that respect, she was very different from the girls from the club who were pretty clearly nowhere near selfless.
Of course, if the only objective is "more human than some humans" then we're setting the bar pretty low I suppose because there are some pretty damaged humans out there. On a scale of sentience that includes Data and remote controlled cars, the Cherry 2000 is far, far closer to the remote controlled cars than Data. I would say that AIs in sci fi actually populate points all along that scale between the remote controlled cars and Data, then beyond them in both directions as well as leaping off the one dimensional scale into additional dimensions.
The plant material will be heavily physically and chemically processed before being used in much the same way that crude oil is now. A good deal of the contaminated land I'm talking about is contaminated with petrochemicals or even natural crude oil in the first place. Given that the source materials for most of our current plastics and fuels are contaminated by definition already, using plants grown in contaminated soil shouldn't really be a problem. The crops won't meet standards for human consumption any more than crude oil will, but the final product should be no dirtier.
Except of course that there's tons of land that isn't suitable for growing food crops that we can use to grow crops for industrial material. There's quite a lot of contaminated land out there, for example.
Spherical means a big cross-section as a target. Depending on how the encounters actually pan out, that might be fine. On the other hand, if you want to dodge lasers or even projectile weapons coming from one ship or cluster of ships very far away, what you want to do is present as small a target to them as possible and make unpredictable lateral movements. For that, a long thin ship with all its armor towards the front might be best. If you're in the thick of attacks from all sides, the spherical shape you suggest may be better. It all depends on so many unknown factors, it's hard to predict. For example, how good the targeting is. To dodge weapons firing at relativistic or light speed, you might be able to move out of the way continually to make a poor target, but that only works if the distances are great enough and if it's even possible to keep moving around like that without running out of propellant. At the 150,000 kilometers (light has to go from you to them for them to note your position, then they have to fire the laser back for a round trip of 300,000 km) it would take for a ship to have 1 second to move to a new position, the best collimated, most powerful lasers we have now would be spread out so much they might as well be a flashlight beam so dodging the best lasers we have now would be unnecessary. Also, even if we could deliver a pinpoint high-powered laser at that range, we may not be able to target it well enough, so moving around randomly might not actually decrease chances of a hit. On the other hand, if the lasers and the targeting get good enough (and if there aren't absolute physical limits preventing it), then moving to dodge becomes a viable strategy to reduce the odds of taking a hit.
Ultimately, technological space warfare would be just like technological warfare on Earth. Balances would be found in ship design and strategy, then changes in technology or simply new ideas in strategy (or new implementations of old ideas) would come along and completely obliterate that balance. Big slow carrier ships with a carrier group to protect them might make sense in a given strategic situation. Then someone might develop a way to get 50% more propulsion out of the smaller craft that actually do the fighting and all of a sudden the carriers are obsolete and go into mothballs. A new battlefront comes into play with greater demand for manoeuvring from the smaller craft or a new strategy or innovation from the enemy requires the same and suddenly carriers are practical again. The enemy finds a reliable way to take out carriers regardless of the protection of the carrier group and carriers are out again and the smaller craft that do the fighting have to get a bit bigger. Someone finds a better countermeasure to protect carriers... etc., etc., etc. The designs, technologies and strategies that work will keep changing and changing. Super-effective, game changing weapons will become obsolete from simple changes in tactics. It will probably never settle on just one set of warship designs.
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Yes, but if you accept the fact that rescue missions will be impossible anyway, then it's a non-issue. Pretty much every astronaut who has ever gone up has accepted that fact. Even the astronauts on the ISS, in LEO have no realistic chance of rescue if something goes wrong and their escape Soyuz craft is unusable for some reason. No-one has a rescue rocket standing by to save them. Unless there happened to be a resupply mission coinciding with the disaster, they'd have to be able to wait months for rescue. On the moon? Forget it. So, for the time being, "abandoning it for safety reasons, medivac, or sending up emergency supplies/repair parts, etc" is no more viable a prospect on the moon than it is on Mars.
What, are you crazy?
The gravity on the moon is half what it is on Mars. Mars has an atmosphere suitable for aerobraking and that actually provides a fair amount of radiation protection. It also may allow for lighter than air survey craft. The atmosphere also protects against micrometeorites, unlike the total vacuum of the moon. The atmosphere can also be processed to make methane and oxygen. Mars has a lot more water than the moon. It also has significant amounts of percholarates. The day is only fractionally longer than than that of Earth, making solar power practical, unlike the month long day on the moon.
Actual pluses for the moon include the fact that it has higher insolation than Mars, being closer to the sun. Of course, the month-long night kid of ruins that. The moon also requires marginally less power to reach than Mars, but since it takes less power to land on Mars since you can aerobrake, that's not really a factor. It matters when you're trying to lift off again, of course. You do need to spend longer in transit to Mars than to the moon, which increases the radiation exposure of the astronauts (though to perfectly acceptable levels with the right precautions). Don't give me the nonsense about the effects of isolation driving the astronauts crazy though. Pretty much every study ever done on it, along with the real world experience of the various space stations we've put up have put that one to bed.
Overall, Mars wins. It has much better prospects than the moon for the long term survival of a colony. People used to say that we should perfect colonizing the moon first, then move on to Mars, but Mars, despite not being closer, is safer and cheaper (marginally, but the more readily usable in situ resources take the win).
You can power a rocket launch with green renewable solar power. Just plug a solar power plant into a gas extraction/processing plant that sucks in air and produces liquid oxygen and methane. Then you use the liquid oxygen and methane to fuel your rocket.
Not that I think President Obama has been doing a particularly good job or that he's kept his campaign promises or anything like that, but I'm still astounded at the depths partisans will sink to in order to malign him. I mean, sticker shock at the pump is pretty harsh at the moment, but calling them "Obama levels" is disingenuous since they were this high, and higher, before he became President. It's sort of like when people blame the financial crisis on him and you're left sort of scratching your head. You can assume that those people just have short memories, but I remember people blaming him for the financial crisis within a week of him being elected (note: within a week of being elected, not within a week of taking office). That kind of magical thinking is just bizarre.
As for oil on Mars, importing it would be ridiculously expensive, but it could be useful as an in situ resource. It could be great for making rocket fuel for sending natural resources from Mars to Earth. If we could make everything (except maybe a few lightweight items like microchips) to manufacture rockets on Mars, then, from an Earth perspective, it actually would be financially viable to ship petroleum products to Earth from Mars. Of course, if the infrastructure on Mars ever gets that developed, then the resources would be more valuable in the local economy.
It took almost 90 years and a civil war for us to figure out that freedom applies to everyone or no-one. [wikipedia.org] Even those members of society we don't like.
The civil war ended in 1865. The US didn't give women, regardless of color, the right to vote until 1913. The civil rights movement didn't even gain real, national traction until the 1950's. The actual rights of the young are still a confusing mess.
No, not a cheque for the revenue generated. He's clearly entitled to from $750 to $150,000 per infringement. The award could then be reduced to $2,250 per infringement, just like for Jammie Thomas.
Believe me, that's certainly a concern too. It's just that it's not the _only_ concern. I just don't understand why people can only focus on one thing. The debate of the general public on air pollution (not that of experts, but the general public and the biased "experts" that polluting industries present are the ones that politicians listen to most) seems to focus only on climate change. The reality is that air pollution matters, climate change or not. To listen to some of the global warming "skeptics", if global warming isn't happening (or if it is, but it's not caused by humans, or if it is and it's caused by humans, but it's actually a great thing!!!) then all concerns about air pollution and dwindling fossil fuel supplies can just be thrown out of the window.
Why does this treat particulates as only a concern because they contribute to climate change? That's a potential problem, to be sure, but particulate emissions are a much more immediate environmental concern for those breathing them in. If the levels have been underestimated this much, that's a problem for people's health, especially along highways and in cities. Why does climate change have to be the be all and end all of all environmental impact discussions? Is it because it's so contentious and the ongoing feud drives page hits?
Yes, I know. Sorry my post was a wall of text, but if you'd read it you would see that I covered that. I'll explain it again and keep it briefer. As a car climbs the space elevator, it's velocity around the earth increases. Once it's about 2/3rds of the way to the altitude of geostationary orbit, it has achieved orbital velocity (for a lower orbit than the altitude it's at). Once it reaches geostationary orbit, it can hop off and stay in geostationary orbit, where the delta-v required to get anywhere in the solar system is drastically less than it is on Earth. The tether has to extend _past_ geostationary orbit, however. Beyond that point, anything dropping off the tether will be thrown into a higher orbit. Dropping off at around 50.96 km puts a payload into trans-lunar orbit. Dropping off around 53,100 km puts a payload at escape velocity. After that, you still need rocket propulsion for manoeuvring and braking/landing and so forth, but the vast majority of what you would have needed is eliminated.
You can look at any period of instability or injustice, in any region, at any time in history and ask "Why do they put up with [X]?". Whether it's warlords or just corrupt local politicians, or whatever the issue, it's easy to deride people for allowing the problem to persist. For the people on the ground it's not exactly as easy as you assume to fix things. Also, as far as warlords go (and warlords/bandits/etc. aren't the only problem, they were just the one you brought up that seemed to answer your own question), I think you may not understand how many warlords and their men actually consist of the "few good men" who put paid to the previous warlord, but then headed in the wrong direction, or are "good men" to one group and vile oppressors to another.
In the long run, people do things to improve the situation, and it does improve, then things can happen to set things back. Even if progress is steady in the right direction, it can take decades and decades and it's essentially a process of swimming upstream against all kinds of economic and political currents coming from the rest of the world.
You asked: "if they need a tractor, why in hell aren't they building their own tractors?", but then you wrote: "warlords wander large areas of Africa, raping and pillaging where they please. Instead of building dams, water purification plants, water distribution and sewage systems, they invest in guns, draft young children into their "armies", and do their very best to tear down the fragments of civilization that African enjoy."
I think you kind of answered your own question.
The Earth's angular momentum is currently, through tidal interactions, moving the moons orbit out by about 3.8 cm a year. The moon masses about 7.36 × 10^22 kilograms and that's a change in velocity of about 5 * 10^-8 m/s. In terms of delta-v I suppose that's not a whole lot, but in terms of energy it's literally metric tons worth. The line stays up, rather than falling to Earth, in a hypothetical space elevator, because the counterweight is pulling away from Earth enough to counteract the weight of the cable. Take the elevator out to that point and drop off and you're not just going to stay in orbit at that point, you're going to fall away from Earth. Obviously, at that point, you're still going to need rockets for additional manoeuvring, but you're already essentially out of the reach of Earth's gravity.
There's still the question of what happens to the system when you drop something off the end of it like that. You put in energy climbing the tether, but that should have pulled the whole thing back towards Earth (it will if the system is designed so you can pull too hard and overcome the equilibrium of the system). So why can you keep putting payload after payload up it without it dropping down? The answer is that the energy comes from the Earth's angular momentum.
So, your objection is incorrect. Once the space elevator is up, it doesn't need delta-v to keep it up, or to fling payloads into higher orbits (which at that point pretty much means the entire solar system). Realistically, it probably will need rocket propulsion or solar sails, etc. to deal with 1001 equilibrium problems that will crop up. Super long tethers in space are going to be subject to all kinds of oscillations and weird effects we can't predict yet. Not to mention that we'll surely need to move the cable out of the way of space debris from time to time.
All this is kind of moot since the space elevator is still a pipe dream. It takes massive amounts of material in space to begin with and most of that material needs to be some kind of unobtanium that we don't even have a sound theoretical basis for yet. The best we have is that we haven't absolutely proven that a material that strong isn't possible yet. Even if we do find one strong enough, there's a ton of other physical requirements for it that it has to meet. The overall idea has some merit, but for the time being we should stick to ideas that we actually can build with real materials. Space elevators might be out, but skyhooks are a possibility. Also launch loops are a possibility. We might also be able to build short space elevators to low earth orbit orbital rings. An orbital ring would basically be a non-anchored version of a launch loop consisting of two tether loops rotating slightly faster than their orbits require, but in opposite directions. No mechanical system could touch the cables, but a magnetic system could, and a station could sit between them and have a tether of only 100 km or so descending into the atmosphere. Some materials like kevlar, fibreglass, and graphite fibre have breaking lengths sufficient for a space elevator that short. Once you actually have the payload in low earth orbit, you could then magnetically lock it to the orbital ring and accelerate the cargo along it until you release it. There are lots of other ideas for ways to make a tether system to space that can get around the problem of the breaking strength of the cable. For example, you can have a set of tethers on very complicated hybrid orbits that essentially play hopscotch with the earth and dynamically support a web of variable length cables that in turn support a space elevator to low earth orbit which then proceeds in longer and longer similarly supported sections until it gets to geostationary orbit.
Hopefully, we'll get advances in propulsion technology, or at least in the economics (it would be nice if we could get to the point where the materials and fuel of the rocket weren't negligible line items of the entire cost of launching) of rocket propulsion that will render i
That would be before 1783 then. Before then, human flight hadn't been achieved (on record, anyway) and was strictly in the realm of science fiction and mythology. So the only airspace anyone was likely to even consider is that reachable by an overhanging tree limb or part of a structure. Perhaps objects ballistically flung across the property might have been considered too. I highly doubt anyone at the time considered property rights to extend infinitely into the heavens.
Also, I believe I covered in the original criticism the fat that the borders of the property are in fact in motion with respect to the rest of the universe. I think I forgot to point out, probably because it's obvious, that you don't have to go out very far (about 4.3 billion kilometers depending on latitude, which is about ) before the borders are superluminal, making it physically impossible to actually locate anything inside the (infinite) majority of your property for any significant length of time.
I would really, really like to see a reference to the law that defines this.
I think with a space elevator the idea is that it's the earth's angular momentum you're using.
2,300 patents on H.264? I'm pretty sure you can implement H.264 in less lines of code than that.
That doesn't really answer my question of what counts as "over" your property though. There's very clearly a problem with that legal theory in that it doesn't define things very well geometrically. What kind of projection does the area "over" someone's property use. Is it a point projection from the center of the Earth that grows exponentially as it projects out into space, or not. To illustrate it better, imagine your property is perfectly circular. One projection is a cone with the point at the center of the earth and extending through your property so that the circumference of the cone touches the edge of your property and the other is a cylinder sitting on your property line and extending out into the universe parallel to a line that goes from the center of the earth and through your property.The first means that if your property borders another property, the border of your airspace borders theirs all the way out to infinity. The second means that the airspace borders diverge immediately and there's a tiny no-mans land between the two that grows at altitude.
This isn't meant to be 100% serious, it's just to illustrate how stupid the idea of projecting airspace indefinitely above someone's property is. The legal principle you're talking about doesn't actually take reality into account. It really only considers airspace on the scale of trees or buildings.
Are any of the patents on PostScript even still in force?
I'm curious about that airspace. Does it only extend to the top of the atmosphere, or all the way to the end of the universe? And does it operate as a projection from the center of the Earth outward so that at 2x the Earth's radius from your property straight up the horizontal cross-section of your property is 4x the area of your property on the ground and 16x the area at 3 Earth radii and so forth, or do the lines stay parallel to a line from the Earths center and through the exact geometric center of your property so that the cross-section is exactly the same area no matter how far away you are? I prefer the second option, because it leaves lanes that aircraft, or at least spacecraft can travel through as long as they're high enough. It's a bit unfair on people whose property is very, very large though because the area of the cross-section of their airspace is a less than their measured land area because of the curvature of the Earth. Plus, the second approach doesn't jibe with mineral rights because those must logically extend downward to a point at the center of the Earth, otherwise they would intersect everyone else's mineral rights. So, logically, airspace would extend the same pattern. I wonder how ownership of celestial bodies like the moon and the sun is handled. Temporarily owned by whoever's property cone it happens to be passing through at the time?
Or maybe airspace rights over property actually follow some sane principle? Up to a certain low altitude, for example?
The moons orbit is oblong, so you'd have to have some method by which the cable length could change. You need a cable strong enough to support its own weight. Gravity drops off as altitude increases by the formula g = 9.8 m/s^2(r/r+h)^2 (r is the radius of the earth and his your height), so it's 100% at the surface (very slightly less if you're at the equator), 96.937% 100 km up, 94.012% 200km up, 85.990% 500km up, 74.730% 1000 km up, 57.955% 2000 km up 37.770% 4000 km up, 19.678%. 8000 km up and so on. Even at geosynchronous orbit altitude (which may or may not be relevant depending on how this cable is being managed) where gravity is 2.287%, the average weight of the 35,800 km of cable to that point is about 15.172% of its Earth weight. Out at 325,000 km, which is about the distance of the L1 point between the Earth and the moon the gravity is .037% of what it is on Earth (not at the actual L1 point where it's cancelled by the moons gravity, this is just an approximation, not taking all forces into account) the average weight of the 325,000 km of cable is still about 1.932% of its Earth weight. So, if you need to stretch a tether out to Geosynchronous orbit, it needs to be strong enough to hold 15.172% of the Earth weight of 35,800 km of material. If the tether masses 1 kg per kilometer, that means it has to be strong enough, at that thickness, to hold the Earth equivalent of .15172*35,800=5431.576 kilograms. Tapering the tether can help, of course, but we still don't have any materials strong enough. For the L1 point, it's equivalent to holding 6279 kg on earth with that size cable.
Then there's the problem that the moon isn't in a geosynchronous orbit, so you can't tether the cable at a stationary point on earth. The poles aren't stationary, so the best you can do is anchor to tower, built on a train on a huge circular track around one of the poles.
Of course, the cable doesn't actually need to be a straight line to the moon. If you could make a tether to geosynchronous orbit, you could then have another tether from there to the moon. For that matter, you might be able to build a 60,000 mile tether that circles the earth at slightly greater than orbital speed (maintained by propellant brought up from earth on the space elevator) then attach multiple secondary tethers that loop around the earth towards the poles where they connect to smaller tether rings suspended above each pole with a station suspended in a web in the middle and a variable length tether that need only be a 100 km long or so (and could be supported by dirigibles through a good portion of the atmosphere) that tethers to a polar base station. You could take an elevator up at the pole, then down along one of the loops to the equatorial ring. From the equatorial ring, you could suspend another ring further out, or perhaps just spokes out to additional stations. From one of those, you could potentially even build a tether all the way to the moon and set it up on an orbit that jump ropes the Earth. Of course, the tether all the way to the moon would hardly be necessary. Once you're out to the orbital ring, if it's fast enough, you can just drop off and fall toward the moon, it would be a heck of a lot faster than pulling an elevator car along 400,000 kilometers of tether. At the moon end you could have another space elevator. The one at that end could use the same equatorial ring with polar elevator trick, but the moons smaller size and lower gravity mean that you could actually have a plain old space elevator right to the surface.
Of course, the above idea might have a lot of problems. Getting that giant orbital lasso trick to actually work might be next to impossible. Also, such a long tether going around the entire Earth is going to have to be carefully designed. It could run into some really interesting electrical effects that could instantly fry it. On the other hand, they could also be used as a method of powering the whole thing. In any case, it's a massive endeavour. You would have to start
Fair enough. Of course, the post he was replying to was talking about 100Gbit speeds. These threads do seem to drift.
I was thinking in terms of real humans rather than movie ones. I do remember the club he went to in the movie where they had lawyers on call to negotiate dating contracts and the ex-girlfriend and the robot sitting down for sandwiches in the desert at the end. Even in the movie universe though, those other girls presumably had real feelings and desires underneath all of the social constructs they were living within (maybe not the ex-girlfriend). The robot though, was pretty clearly just going through the motions without even any desires. It did the housework and put on a cheery face, brought him his slippers and a Martini or whatever and said that it loved him in an adoring voice a lot. Just a well-designed program. She was also easy in every sense of the word. No complaints, completely compliant, utterly selfless in every sense of the word (especially in the sense that she didn't have one). In that respect, she was very different from the girls from the club who were pretty clearly nowhere near selfless.
Of course, if the only objective is "more human than some humans" then we're setting the bar pretty low I suppose because there are some pretty damaged humans out there. On a scale of sentience that includes Data and remote controlled cars, the Cherry 2000 is far, far closer to the remote controlled cars than Data. I would say that AIs in sci fi actually populate points all along that scale between the remote controlled cars and Data, then beyond them in both directions as well as leaping off the one dimensional scale into additional dimensions.
The plant material will be heavily physically and chemically processed before being used in much the same way that crude oil is now. A good deal of the contaminated land I'm talking about is contaminated with petrochemicals or even natural crude oil in the first place. Given that the source materials for most of our current plastics and fuels are contaminated by definition already, using plants grown in contaminated soil shouldn't really be a problem. The crops won't meet standards for human consumption any more than crude oil will, but the final product should be no dirtier.
Except of course that there's tons of land that isn't suitable for growing food crops that we can use to grow crops for industrial material. There's quite a lot of contaminated land out there, for example.
Spherical means a big cross-section as a target. Depending on how the encounters actually pan out, that might be fine. On the other hand, if you want to dodge lasers or even projectile weapons coming from one ship or cluster of ships very far away, what you want to do is present as small a target to them as possible and make unpredictable lateral movements. For that, a long thin ship with all its armor towards the front might be best. If you're in the thick of attacks from all sides, the spherical shape you suggest may be better. It all depends on so many unknown factors, it's hard to predict. For example, how good the targeting is. To dodge weapons firing at relativistic or light speed, you might be able to move out of the way continually to make a poor target, but that only works if the distances are great enough and if it's even possible to keep moving around like that without running out of propellant. At the 150,000 kilometers (light has to go from you to them for them to note your position, then they have to fire the laser back for a round trip of 300,000 km) it would take for a ship to have 1 second to move to a new position, the best collimated, most powerful lasers we have now would be spread out so much they might as well be a flashlight beam so dodging the best lasers we have now would be unnecessary. Also, even if we could deliver a pinpoint high-powered laser at that range, we may not be able to target it well enough, so moving around randomly might not actually decrease chances of a hit. On the other hand, if the lasers and the targeting get good enough (and if there aren't absolute physical limits preventing it), then moving to dodge becomes a viable strategy to reduce the odds of taking a hit.
Ultimately, technological space warfare would be just like technological warfare on Earth. Balances would be found in ship design and strategy, then changes in technology or simply new ideas in strategy (or new implementations of old ideas) would come along and completely obliterate that balance. Big slow carrier ships with a carrier group to protect them might make sense in a given strategic situation. Then someone might develop a way to get 50% more propulsion out of the smaller craft that actually do the fighting and all of a sudden the carriers are obsolete and go into mothballs. A new battlefront comes into play with greater demand for manoeuvring from the smaller craft or a new strategy or innovation from the enemy requires the same and suddenly carriers are practical again. The enemy finds a reliable way to take out carriers regardless of the protection of the carrier group and carriers are out again and the smaller craft that do the fighting have to get a bit bigger. Someone finds a better countermeasure to protect carriers... etc., etc., etc. The designs, technologies and strategies that work will keep changing and changing. Super-effective, game changing weapons will become obsolete from simple changes in tactics. It will probably never settle on just one set of warship designs.