Angular momentum would mean that it would definitely NOT fall "straight" down. 40,000km is ~6x the radius of the Earth, meaning it has ~6x the tangential velocity of the Earth-tethered end. That cable is going to wrap itself around the planet.
You might need to re-read my post. I said "For at least the first few hundred kilometers of tether, down is going to mean on top of the anchor station and the area immediately around it". I later said "further out, a breaking cable is going to have other forces pulling it away from falling right onto the anchor point, but it's still going to be falling down", that's down as in towards the Earth, not down as in on top of the anchor station. The point was that the parts that are going to be going slowly enough that they won't hit the atmosphere at a serious clip are going to be falling in an area you can have pretty good control over. The rest of it will hit the atmosphere so hard it should mostly just burn up.
As for the thickness of the cable, I think you're a bit confused. The material would have to be very lightweight, we both agree on that. But you seem to be imagining a lot more thickening of the cable than would be necessary. Exponential growth of a tapered cable is a bit of a simplification, though it would need to get thicker all the way to geosynch. We know that if a space elevator could be built, it would require materials with much higher tensile strength to weight ratios than we currently have access to in order to be practically built. The higher the strength to weight ratio of the material, the less thickening of the cable would be required as it went up. A material actually strong enough to support its own weight to geosynch wouldn't need to thicken at all, but would have a strength to weight ratio slightly higher than the most optimistic projections for carbon nanotubes. At those optimistic, but still within the bounds of reason, projections for carbon nanotubes, the cable would need to be 1.2 times its sea level thickness at geosynch. So, assuming some amazing materials development (and we can't really have a discussion about space elevators without doing that) a cable which _averages_ 5 cm along its whole length would be about right. If you built it out of steel, it would need to be at least 42,000,000,000,000,000 times thicker at geosynch than at sea level. Out of kevlar, it would only need to be about 16,000 times thicker. Out of zylon, _only_ about 700 times thicker.
So, if we're talking about the hypothetical situation of what happens if a space elevator fails, we're not talking about a cable of enourmously massive thickness, even at the geosynch end. If it falls, it either hits the ground relatively lightly, or it rams the atmosphere hard enough to burn up.
I'm a bit too young to remember, but my parents cannot recall any such derision of either so I suspect it's a bit of revisionism like the "flat earth" that no sailor that ever went up a mast believed in.
They certainly existed, but they were wrong, so mostly they're forgotten, especially by the people who are embarrassed to have whole-heartedly believed them. It's a mix of the same old stuff about humans not being able to withstand high acceleration (even high velocity, which is nonsensical), weightlessness being fatal, space being full of deadly microbes, cosmic rays being unsurvivable, etc. You don't have to look far for some of those theories being promoted today. For example, The Fine Article. True, it's not claiming that the cosmic rays would be instantly fatal, just that it might create an increased risk for Alzheimer's-like symptoms later in life. The claims then reach the press and get presented in the mindset of "so much for space travel", then they reach somewhere like Slashdot and people crawl out of the woodwork to lambast anyone who thinks humans should travel in space. As another example, there's the moon hoaxers. According to them, humans really can't survive passing through the Van Allen belts, etc., etc. They're a minority but, if you include all the mentally malleable and lazy people who believe them when they're showcased in gaudy "documentary" shams on TV, they're a disturbingly large minority.
Same for the Flat Earth theory. No-one sensible believed it. The fact that the Earth was a sphere and even very accurate measurements of the circumference of the Earth have been known since antiquity. The problem is, a surprising number of very non-sensible people seem to manage to end up with a lot of power and influence. I've had to deal with seeking funding and/or approval from people whose understanding of the subject at hand was incredibly poor or even incredibly wrong. Nevertheless, they were very sure they were the smartest people in the room, and if you hurt their egos too much by trying to correct their misunderstandings, you were out of luck. Actually, Christopher Columbus is a great example of people in authority without a clue on the subject they were providing funding for. He was proposing a suicide mission, but he was a nut and thought that everyone who actually knew what they were talking about was wrong about the circumference of the Earth and he got people holding some pretty enormous purse strings to believe him. The world, even today, is full of people who will believe all manner of hokum and hex while disbelieving basic science. Sometimes even, otherwise brilliant people will end up with crazy fixed ideas. Fred Hoyle and his campaign against the "hoax" he believed Archaeopteryx to be springs to mind.
As for Mars retaining an atmosphere, there are a number of important details to consider there. The example of Titan, with one eighth Earth gravity and 150% of Earth's atmospheric density certainly demonstrates that being less massive than Earth is no obstacle to retaining a dense atmosphere. Venus is another example of atmospheric density at least not having a one-to-one relationship to the mass of a planet. Energetic causes like meteors and solar wind are the kinds of things that lose atmosphere to space on a planet like Mars. There's also the unanswered question of how much of the atmosphere was sucked up into the ground through various processes versus being ejected into space. The actual rate of ejection into space is also in question. Many people seem to give the figure of 10 thousand years as if it were settled but that seems wildly pessemistic. The magnetic field of Earth functions as a shield diverting some of the solar wind so that it doesn't strip the atmosphere and, when the solar wind does strip Earth's atmosphere (mostly of hydrogen) it returns most of the lost atmosphere back to Earth and Mars doesn't have that protection and escape velocity is lower, so clearly it's a lot more vulnerable than Earth, but no-one really has a good ide
I suppose we can keep off each others lawns:) Or walk all over them too. That's what lawns should be for.
A colony we could essentially do now (not now as in today, but with our current level of technology) with resupply, or just a boatload of initial supplies. I certainly don't think terraforming is within our current level of technology. Discussion of it does come up during these discussions, however, and it tends to get speculative and hypothetical. Personally, I find it intellectually refreshing to think about the possible solutions to these problems. Even with all the things we don't know about the problem in the first place, thinking about it exercises what you _do_ know and it reveals to you that you don't know the things that you don't know. After all, if you never let your mind wander then you will miss the chasms of ignorance in your own knowledge. Sometimes, when you can find those chasms, you can try to fill them. Sometimes you can float an idea and someone will totally destroy it with a clear, informative explanation of why it won't work that really expands your knowledge. I miss the days when that seemed to happen a lot more on Slashdot. I miss the glory days of newsgroups like alt.destroy.the.earth and alt.pave.the.earth as well. The subjects were ridiculous in pretty much every practical sense, but the thought experiments were enlightening.
Overall, I think that if we actually had technology on the level and scale required to terraform Mars, we could find a way to replicate the function of the magnetosphere. Actually truly understanding how planetary magnetic fields arise and why Mars doesn't have a coherent one would obviously help a lot and I think that's the kind of useful science that might someday be done from research stations on Mars and other locations in the solar system if we can ever really get out there. That can be one tiny, tiny baby step towards actually terraforming Mars if we ever do.
At present, it's a virtual certainty that pretty much everyone involved in the last effort to move a human being out of LEO will be dead before we manage to actually get another one out there. In the late 60's/early 70's, years before I was even born, it was done on approximately a 5 month schedule for 4 years. Then it just stopped, and it's run backwards, and the country that did it not only doesn't have manned spaceflight anymore, it doesn't even have a coherent plan for achieving manned spaceflight again any time in the next decade or so. It's all so frustrating, I think some of us can be forgiven a little speculation about the future. I think we can even be forgiven a little derision for the latest person to "prove" space travel is impossible for astronauts to survive the same way there were people "proving" that surviving supersonic flight was impossible back in the day.
There's no reason to put "blue" in quotes there. The sky is blue (when it's blue) because of its optical properties. Explaining it in more detail is informative, but doesn't make it not really blue. Same as how a deeper understanding of the electromagnetic forces that bind together atoms and molecules doesn't mean that objects never really "touch" each other, as deep a thought as that may seem when you're eight and you learn some basics of atomic theory.
A space elevator has a massive host of problems, but the tether falling disastrously to the ground doesn't seem to be one of them. To start with, it would need to be a lightweight tether. It would be tapered (and probably ribbon shaped) close to the Earth, but approach a more uniform thickness closer to the Earth. If it fell in the atmosphere, it would probably have a relatively low terminal velocity. Thing is, where-ever it would need to be anchored would probably be out of the way in the middle of nowhere, or maybe even on an island. If the tether falls, it is going to fall down. For at least the first few hundred kilometers of tether, down is going to mean on top of the anchor station and the area immediately around it. The only thing that would prevent that is if it's very aerodynamic and drifts. If it's that affected by air, then it's going to have a low terminal velocity, and it won't do much damage unless it lands right on a person. Further out, a breaking cable is going to have other forces pulling it away from falling right onto the anchor point, but it's still going to be falling down, from a very great height, with no atmosphere to slow it until it hits the atmosphere like a brick wall and probably burns up before reaching the ground. A 5 cm cable, 40,000 km long, spooled one layer thick would cover about 2 square kilometers. That's a fair amount of area, but not that impressive covering an entire planet that's mostly ocean.
Basically, the cable burns up or breaks up or falls at a reasonably low speed onto a fairly small fraction of the surface of the planet, doing some damage to buildings and so forth, and maybe even hitting a few people. Not really that big a deal.
Sir Fleming was actively searching for antibacterial agents. He wasn't explicitly testing moulds for antibacterial properties at the time, he just had a contaminated petri dish of staphylococci, so in that sense he may have stumbled upon it. But, penicillium is not exactly an uncommon mould. Millions of people had surely "stumbled upon" it before him, but not recognized the significance.
Burton was, while widely travelled, still a firm believer in the racial superiority of white Europeans. It wouldn't be surprising if I was running into embellishments by Burton.
Were you meaning to reply to a different post? Just wondering since I've certainly not suggested anywhere in this thread that you can just add more gravity to a planet, nor can I find anywhere that I talk about artificial magnetospheres or capping the atmosphere although I did mention such ideas in another post. You could create centrifuge habitats (high speed trains on circular tracks ) if it turned out that people needed it to maintain bone density, but that seems unlikely (although we'll never find out until we actually colonize another planet with different gravity or create a spinning space habitat) for some highly localized simulated gravity. As for adding a magnetosphere, I did mention that in another post specifically in the context of terraforming the entire planet. Relative to a task like terraforming, which I wasn't advocating as something we could even hope to accomplish at present, creating an artificial magnetosphere might be possible. Actually understanding the nature of planetary magnetic fields would clearly be necessary before even conceiving of _how_ to do that, which is why we need to take the baby steps of exploring space in the first place.
Anyway, I certainly never said "just terraform", and I'm not sure why you're talking to me about what happened to this place. You may have, like me, lurked on Slashdot for a long time before actually getting an account, but it still looks, based on our UIDs, like I've been participating here for a lot longer than you have. If one of us has the right to complain about the other walking on their lawn (#@%@# kids!), it would seem to be me.
The main reason they shouldn't be behind bars is because now the situation has gone completely out of the control of the parents. They probably went to the police determined to show the kids the severity of the situation. The problem is, the parents may soon discover that they themselves didn't understand the severity of the situation. If they decide that it's gone far enough and that the kids have faced enough, they will probably discover that their feelings are irrelevant and that the children now belong to the system which may end up heavily abusing them directly or indirectly. The parents may end needing to choose between either abandoning their children to their fate, or having to spend tens of thousands of dollars on legal fees.
There are plenty of arguments one way or the other about whether or not harsh punishments are effective behaviour modification. The kind of prolonged punishment sending your children to prison, even a juvenile one, represents passes well beyond that debate.
The problem is how you determine which "fair share" they're paying for. If it's actual wear and tear to the roads, that's pretty much all caused by big trucks or by snow clearing (ploughs and, even worse, salt). Passenger vehicles cause essentially zero wear on the roads compared to those other factors. Fuel efficient cars tend to be even lighter and therefore even less likely to cause damage. You could say that the "fair share" is tied to how much space/time the vehicle occupies. The problem there is that it creates a negative incentive for state and local governments to care about preventing traffic congestion or providing optimal routes for drivers. Those governments already seem to consider driver's time to be irrelevant to cost calculations, so suddenly making it _relevant_ (by positively correlating driver time/distance to revenues) is a frightening thought. You could dismiss that thinking as paranoid, but you would have to ignore all the debacles with things like red light cameras where local governments have intentionally created unsafe conditions at red lights to drive up revenues.
How to pay for roads does become an issue, of course. Raising fuel taxes across the board when some people have much more efficient cars than others seems unfair to the drivers with less efficient cars (some of whom may be unrepentant gas-guzzler drivers, but others of whom are probably too poor to afford a new car). Mileage taxes on fuel-efficient cars are a very bad incentive since conserving fossil fuels is the behaviour a responsible government should be encouraging. Roads and similar infrastructure are the kinds of must-have items that benefit pretty much everyone, even those who don't have cars or drive anywhere, so rightfully could come out of general taxes applied to everyone, rather than just to drivers, but people who don't drive or don't drive very much will scream that they're being forced to pay for everyone else, ignoring the fact that the civilization they rely one wouldn't run without roads. The roads need to be funded somehow, though.
The worst case scenario (barring the big-brother box that tracks your car everywhere and bills based on that) is the government throwing up their hands and selling millions of acres of roadway to a private company (coincidentally run by some cronies) for a dollar and a vague promise of not abusing the position, then letting them run a toll system that makes the old, taxed roadway look cheap, while simultaneously being kept in worse condition and with traffic gridlocked from whatever toll-collection scheme they think up.
I would expect terraforming to take more than just a few hundred years, but I suppose that would depend on what technology we can muster. In any case, we clearly wouldn't want to (and wouldn't be able to) jump straight into terraforming. A permanent colony would be the starting point. I don't think it's as unlikely or impractical (for a definition of practical that doesn't require $X return on investment within Y years) as you seem to think. With resupply missions, we have the technology to do it right now (for a definition of "have the technology" that imagines we can at least achieve the kinds of space missions we were technologically capable of back when my father was a teenager). For a fully self-sustaining colony, we certainly need more work, but it's always difficult to reach self-sustaining without bootstrapping it into place.
For example I suggest reading: One thousand and one nights
Do you recommend a version of that? I tried getting through the Sir Richard Burton version and eventually choked on all the racism. Wasn't really sure if it was coming from the original sources or from Burton.
Technically speaking, the only constitutional protection against slavery is the bit about "cruel and unusual punishment", which is _very_ open to interpretation. The constitution still allows slavery as a punishment for a crime otherwise, and I don't think it really addresses contracts of indenture. Technically speaking, it could be made a criminal offense to violate an employment contract, punishable by being forced to fulfil the employment contract. The Supreme Court might decide that the punishment was cruel and/or unusual, but I'm not so sure they would.
The next question is how severe the punishment can be for then refusing to work. Based on what I've heard out of prisons and jails where there are currently people performing slave labour in the US, they can, at the very least, put the non-compliant slave into solitary confinement and restrict them to a bread and water diet. Exactly how legal beatings are is up in the air. Prison guards are certainly allowed to use "compliance blows", pepper spray, physical restraint, etc. on prisoners who refuse to go where they're told or do what they're told. I'm not sure exactly where the courts stand on those techniques when the "where" is a workstation and the "what" is some form of labour.
N2 28 g/mol, CO 28 g/mol, CH4 16 g/mol, H2 2 g/mol, H2O 18 g/mol, He, 4 g/mol, NO 30 g/mol, Ne 20 g/mol. I'll grant you Ar 40 g/mol. I'm not sure the mass of molecules really count for this sort of thing though. Do molecules being stripped by solar wind actually stay together in such energetic conditions? We might only be able to consider the masses of individual atoms. Anyway, oxygen, either in molecular form or as single atoms, isn't exactly heavy, but it's not really that light either compared to most of the other stuff typically found in a planetary atmosphere.
To make it safe, they would have to turn it into what we currently call “flag” or “touch” Football. It would be a different sport.
Or they could go the rugby route and just get rid of all that padding. There would be a modest increase in severe, acute injuries, and a drastic decrease in these long term ones. This would largely be based on the players learning not to use their heads as weapons.
Millions of years are an eyeblink in geologic terms. The chances of being hit tomorrow are not nil. They are very small, but it's a virtual certainty that it will happen again. At that point, unless we have the capability to either stop the piece of rock, or to escape it, we may be doomed. Stopping it or escaping it both require a healthy presence in space.
Go look at the history of the space program, and how something as simple as a person eating dinner and taking a shit afterward had to be rethought from the ground up to work in zero-gravity.
Yep. Using a wet/dry vac as a toilet really was just an unimaginable adaptation. Eating pureed food out of tubes and drinking out of spill proof cups, there's another one. Turns out that now, for the most part, they just send up regular food with a review process beforehand and tell the astronauts not to be messy eating it.
It also assumes lead/concrete shielding is the only option
Very true. If, for example, you're setting up a Mars colony, you need to take a lot of supplies and equipment with you. All those supplies and equipment would make great shielding.
Temperatures on Mars aren't really much worse than Antarctica. Also, since the Martian atmosphere is so thin, there's a lot less heat transfer to the atmosphere through conduction and convection. So, for all practical purposes, you can think of Mars as actually being a lot warmer than Antarctica.
If their real innovation was their control scheme, then it is truly amazing that they managed to get all the glory. Their control scheme was a disaster and wasn't adopted by anyone. At least, not by anyone who didn't kill themselves trying to fly.
You are right that there was a race on to achieve manned powered flight at the time. There were also many dissenters well before the Wright brothers flew. There were those who insisted that it was impossible, and those who insisted that humans would be physiologically incapable of surviving (getting back on the topic of the actual article) and those who simply insisted that it shouldn't be tried for their own bizarre contrarian reasons. Nevertheless, powered heavier than air flight succeeded.
The same kinds of dissent sprang up around spaceflight. There were claims that rockets wouldn't work in a vacuum, that humans couldn't survive the acceleration, or weightlessness, or space radiation, etc. Somehow, the naysayers generally seem to be proven wrong.
As the GP said, you're clearly trying to speak authoritatively on a topic about which you clearly know nothing, or at least very little. Your information is certainly well out of date at the very least. After all, you write: "I am aware of the *possible* existence of even smaller trace amount of water ice on the moon.". Either you don't know what a trace amount is, or you haven't heard about the results of Chandrayaan-1, which strongly suggest millions of tons of water ice in shadowed craters on the moon. Sure, if you averaged it out over the whole moon, it would probably only be a trace amount, but you don't get to call it a trace amount unless it actually is spread out. It's certainly not a meaningless amount of water for even a very large colonization effort. Mars is almost certainly a better target, however.
Pretty much all recent evidence strongly suggests that you're completely wrong about Mars having only trace amounts of water. Soil is very complex, but it can still be made. All those complex organics you mention come from organic processes. You can start with small amounts of soil, or organics grown without soil and compost them to create soil. As for nitrates not being available on Mars, it's theorized that there should be plenty of nitrates on Mars fixed through meteorite bombardment.
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Angular momentum would mean that it would definitely NOT fall "straight" down. 40,000km is ~6x the radius of the Earth, meaning it has ~6x the tangential velocity of the Earth-tethered end. That cable is going to wrap itself around the planet.
You might need to re-read my post. I said "For at least the first few hundred kilometers of tether, down is going to mean on top of the anchor station and the area immediately around it". I later said "further out, a breaking cable is going to have other forces pulling it away from falling right onto the anchor point, but it's still going to be falling down", that's down as in towards the Earth, not down as in on top of the anchor station. The point was that the parts that are going to be going slowly enough that they won't hit the atmosphere at a serious clip are going to be falling in an area you can have pretty good control over. The rest of it will hit the atmosphere so hard it should mostly just burn up.
As for the thickness of the cable, I think you're a bit confused. The material would have to be very lightweight, we both agree on that. But you seem to be imagining a lot more thickening of the cable than would be necessary. Exponential growth of a tapered cable is a bit of a simplification, though it would need to get thicker all the way to geosynch. We know that if a space elevator could be built, it would require materials with much higher tensile strength to weight ratios than we currently have access to in order to be practically built. The higher the strength to weight ratio of the material, the less thickening of the cable would be required as it went up. A material actually strong enough to support its own weight to geosynch wouldn't need to thicken at all, but would have a strength to weight ratio slightly higher than the most optimistic projections for carbon nanotubes. At those optimistic, but still within the bounds of reason, projections for carbon nanotubes, the cable would need to be 1.2 times its sea level thickness at geosynch. So, assuming some amazing materials development (and we can't really have a discussion about space elevators without doing that) a cable which _averages_ 5 cm along its whole length would be about right. If you built it out of steel, it would need to be at least 42,000,000,000,000,000 times thicker at geosynch than at sea level. Out of kevlar, it would only need to be about 16,000 times thicker. Out of zylon, _only_ about 700 times thicker.
So, if we're talking about the hypothetical situation of what happens if a space elevator fails, we're not talking about a cable of enourmously massive thickness, even at the geosynch end. If it falls, it either hits the ground relatively lightly, or it rams the atmosphere hard enough to burn up.
I'm a bit too young to remember, but my parents cannot recall any such derision of either so I suspect it's a bit of revisionism like the "flat earth" that no sailor that ever went up a mast believed in.
They certainly existed, but they were wrong, so mostly they're forgotten, especially by the people who are embarrassed to have whole-heartedly believed them. It's a mix of the same old stuff about humans not being able to withstand high acceleration (even high velocity, which is nonsensical), weightlessness being fatal, space being full of deadly microbes, cosmic rays being unsurvivable, etc. You don't have to look far for some of those theories being promoted today. For example, The Fine Article. True, it's not claiming that the cosmic rays would be instantly fatal, just that it might create an increased risk for Alzheimer's-like symptoms later in life. The claims then reach the press and get presented in the mindset of "so much for space travel", then they reach somewhere like Slashdot and people crawl out of the woodwork to lambast anyone who thinks humans should travel in space. As another example, there's the moon hoaxers. According to them, humans really can't survive passing through the Van Allen belts, etc., etc. They're a minority but, if you include all the mentally malleable and lazy people who believe them when they're showcased in gaudy "documentary" shams on TV, they're a disturbingly large minority.
Same for the Flat Earth theory. No-one sensible believed it. The fact that the Earth was a sphere and even very accurate measurements of the circumference of the Earth have been known since antiquity. The problem is, a surprising number of very non-sensible people seem to manage to end up with a lot of power and influence. I've had to deal with seeking funding and/or approval from people whose understanding of the subject at hand was incredibly poor or even incredibly wrong. Nevertheless, they were very sure they were the smartest people in the room, and if you hurt their egos too much by trying to correct their misunderstandings, you were out of luck. Actually, Christopher Columbus is a great example of people in authority without a clue on the subject they were providing funding for. He was proposing a suicide mission, but he was a nut and thought that everyone who actually knew what they were talking about was wrong about the circumference of the Earth and he got people holding some pretty enormous purse strings to believe him. The world, even today, is full of people who will believe all manner of hokum and hex while disbelieving basic science. Sometimes even, otherwise brilliant people will end up with crazy fixed ideas. Fred Hoyle and his campaign against the "hoax" he believed Archaeopteryx to be springs to mind.
As for Mars retaining an atmosphere, there are a number of important details to consider there. The example of Titan, with one eighth Earth gravity and 150% of Earth's atmospheric density certainly demonstrates that being less massive than Earth is no obstacle to retaining a dense atmosphere. Venus is another example of atmospheric density at least not having a one-to-one relationship to the mass of a planet. Energetic causes like meteors and solar wind are the kinds of things that lose atmosphere to space on a planet like Mars. There's also the unanswered question of how much of the atmosphere was sucked up into the ground through various processes versus being ejected into space. The actual rate of ejection into space is also in question. Many people seem to give the figure of 10 thousand years as if it were settled but that seems wildly pessemistic. The magnetic field of Earth functions as a shield diverting some of the solar wind so that it doesn't strip the atmosphere and, when the solar wind does strip Earth's atmosphere (mostly of hydrogen) it returns most of the lost atmosphere back to Earth and Mars doesn't have that protection and escape velocity is lower, so clearly it's a lot more vulnerable than Earth, but no-one really has a good ide
I suppose we can keep off each others lawns :) Or walk all over them too. That's what lawns should be for.
A colony we could essentially do now (not now as in today, but with our current level of technology) with resupply, or just a boatload of initial supplies. I certainly don't think terraforming is within our current level of technology. Discussion of it does come up during these discussions, however, and it tends to get speculative and hypothetical. Personally, I find it intellectually refreshing to think about the possible solutions to these problems. Even with all the things we don't know about the problem in the first place, thinking about it exercises what you _do_ know and it reveals to you that you don't know the things that you don't know. After all, if you never let your mind wander then you will miss the chasms of ignorance in your own knowledge. Sometimes, when you can find those chasms, you can try to fill them. Sometimes you can float an idea and someone will totally destroy it with a clear, informative explanation of why it won't work that really expands your knowledge. I miss the days when that seemed to happen a lot more on Slashdot. I miss the glory days of newsgroups like alt.destroy.the.earth and alt.pave.the.earth as well. The subjects were ridiculous in pretty much every practical sense, but the thought experiments were enlightening.
Overall, I think that if we actually had technology on the level and scale required to terraform Mars, we could find a way to replicate the function of the magnetosphere. Actually truly understanding how planetary magnetic fields arise and why Mars doesn't have a coherent one would obviously help a lot and I think that's the kind of useful science that might someday be done from research stations on Mars and other locations in the solar system if we can ever really get out there. That can be one tiny, tiny baby step towards actually terraforming Mars if we ever do.
At present, it's a virtual certainty that pretty much everyone involved in the last effort to move a human being out of LEO will be dead before we manage to actually get another one out there. In the late 60's/early 70's, years before I was even born, it was done on approximately a 5 month schedule for 4 years. Then it just stopped, and it's run backwards, and the country that did it not only doesn't have manned spaceflight anymore, it doesn't even have a coherent plan for achieving manned spaceflight again any time in the next decade or so. It's all so frustrating, I think some of us can be forgiven a little speculation about the future. I think we can even be forgiven a little derision for the latest person to "prove" space travel is impossible for astronauts to survive the same way there were people "proving" that surviving supersonic flight was impossible back in the day.
There's no reason to put "blue" in quotes there. The sky is blue (when it's blue) because of its optical properties. Explaining it in more detail is informative, but doesn't make it not really blue. Same as how a deeper understanding of the electromagnetic forces that bind together atoms and molecules doesn't mean that objects never really "touch" each other, as deep a thought as that may seem when you're eight and you learn some basics of atomic theory.
You'll never have 14 psi atmosphere on Mars as it has a 3rd of the gravitational pull at surface level as Earth.
Hmmm. Titan has about an eighth of the surface gravity of Earth and has an atmosphere 50% denser than ours.
I just have to note here that, when catching a baseball you have considerably less than a second to catch the ball.
A space elevator has a massive host of problems, but the tether falling disastrously to the ground doesn't seem to be one of them. To start with, it would need to be a lightweight tether. It would be tapered (and probably ribbon shaped) close to the Earth, but approach a more uniform thickness closer to the Earth. If it fell in the atmosphere, it would probably have a relatively low terminal velocity. Thing is, where-ever it would need to be anchored would probably be out of the way in the middle of nowhere, or maybe even on an island. If the tether falls, it is going to fall down. For at least the first few hundred kilometers of tether, down is going to mean on top of the anchor station and the area immediately around it. The only thing that would prevent that is if it's very aerodynamic and drifts. If it's that affected by air, then it's going to have a low terminal velocity, and it won't do much damage unless it lands right on a person. Further out, a breaking cable is going to have other forces pulling it away from falling right onto the anchor point, but it's still going to be falling down, from a very great height, with no atmosphere to slow it until it hits the atmosphere like a brick wall and probably burns up before reaching the ground. A 5 cm cable, 40,000 km long, spooled one layer thick would cover about 2 square kilometers. That's a fair amount of area, but not that impressive covering an entire planet that's mostly ocean.
Basically, the cable burns up or breaks up or falls at a reasonably low speed onto a fairly small fraction of the surface of the planet, doing some damage to buildings and so forth, and maybe even hitting a few people. Not really that big a deal.
Sir Fleming was actively searching for antibacterial agents. He wasn't explicitly testing moulds for antibacterial properties at the time, he just had a contaminated petri dish of staphylococci, so in that sense he may have stumbled upon it. But, penicillium is not exactly an uncommon mould. Millions of people had surely "stumbled upon" it before him, but not recognized the significance.
Burton was, while widely travelled, still a firm believer in the racial superiority of white Europeans. It wouldn't be surprising if I was running into embellishments by Burton.
Were you meaning to reply to a different post? Just wondering since I've certainly not suggested anywhere in this thread that you can just add more gravity to a planet, nor can I find anywhere that I talk about artificial magnetospheres or capping the atmosphere although I did mention such ideas in another post. You could create centrifuge habitats (high speed trains on circular tracks ) if it turned out that people needed it to maintain bone density, but that seems unlikely (although we'll never find out until we actually colonize another planet with different gravity or create a spinning space habitat) for some highly localized simulated gravity. As for adding a magnetosphere, I did mention that in another post specifically in the context of terraforming the entire planet. Relative to a task like terraforming, which I wasn't advocating as something we could even hope to accomplish at present, creating an artificial magnetosphere might be possible. Actually understanding the nature of planetary magnetic fields would clearly be necessary before even conceiving of _how_ to do that, which is why we need to take the baby steps of exploring space in the first place.
Anyway, I certainly never said "just terraform", and I'm not sure why you're talking to me about what happened to this place. You may have, like me, lurked on Slashdot for a long time before actually getting an account, but it still looks, based on our UIDs, like I've been participating here for a lot longer than you have. If one of us has the right to complain about the other walking on their lawn (#@%@# kids!), it would seem to be me.
The main reason they shouldn't be behind bars is because now the situation has gone completely out of the control of the parents. They probably went to the police determined to show the kids the severity of the situation. The problem is, the parents may soon discover that they themselves didn't understand the severity of the situation. If they decide that it's gone far enough and that the kids have faced enough, they will probably discover that their feelings are irrelevant and that the children now belong to the system which may end up heavily abusing them directly or indirectly. The parents may end needing to choose between either abandoning their children to their fate, or having to spend tens of thousands of dollars on legal fees.
There are plenty of arguments one way or the other about whether or not harsh punishments are effective behaviour modification. The kind of prolonged punishment sending your children to prison, even a juvenile one, represents passes well beyond that debate.
The problem is how you determine which "fair share" they're paying for. If it's actual wear and tear to the roads, that's pretty much all caused by big trucks or by snow clearing (ploughs and, even worse, salt). Passenger vehicles cause essentially zero wear on the roads compared to those other factors. Fuel efficient cars tend to be even lighter and therefore even less likely to cause damage. You could say that the "fair share" is tied to how much space/time the vehicle occupies. The problem there is that it creates a negative incentive for state and local governments to care about preventing traffic congestion or providing optimal routes for drivers. Those governments already seem to consider driver's time to be irrelevant to cost calculations, so suddenly making it _relevant_ (by positively correlating driver time/distance to revenues) is a frightening thought. You could dismiss that thinking as paranoid, but you would have to ignore all the debacles with things like red light cameras where local governments have intentionally created unsafe conditions at red lights to drive up revenues.
How to pay for roads does become an issue, of course. Raising fuel taxes across the board when some people have much more efficient cars than others seems unfair to the drivers with less efficient cars (some of whom may be unrepentant gas-guzzler drivers, but others of whom are probably too poor to afford a new car). Mileage taxes on fuel-efficient cars are a very bad incentive since conserving fossil fuels is the behaviour a responsible government should be encouraging. Roads and similar infrastructure are the kinds of must-have items that benefit pretty much everyone, even those who don't have cars or drive anywhere, so rightfully could come out of general taxes applied to everyone, rather than just to drivers, but people who don't drive or don't drive very much will scream that they're being forced to pay for everyone else, ignoring the fact that the civilization they rely one wouldn't run without roads. The roads need to be funded somehow, though.
The worst case scenario (barring the big-brother box that tracks your car everywhere and bills based on that) is the government throwing up their hands and selling millions of acres of roadway to a private company (coincidentally run by some cronies) for a dollar and a vague promise of not abusing the position, then letting them run a toll system that makes the old, taxed roadway look cheap, while simultaneously being kept in worse condition and with traffic gridlocked from whatever toll-collection scheme they think up.
I would expect terraforming to take more than just a few hundred years, but I suppose that would depend on what technology we can muster. In any case, we clearly wouldn't want to (and wouldn't be able to) jump straight into terraforming. A permanent colony would be the starting point. I don't think it's as unlikely or impractical (for a definition of practical that doesn't require $X return on investment within Y years) as you seem to think. With resupply missions, we have the technology to do it right now (for a definition of "have the technology" that imagines we can at least achieve the kinds of space missions we were technologically capable of back when my father was a teenager). For a fully self-sustaining colony, we certainly need more work, but it's always difficult to reach self-sustaining without bootstrapping it into place.
For example I suggest reading:
One thousand and one nights
Do you recommend a version of that? I tried getting through the Sir Richard Burton version and eventually choked on all the racism. Wasn't really sure if it was coming from the original sources or from Burton.
I've learned to instinctively take headshots,
Sorry, why would this make someone more proficient in a real world firefight?
Technically speaking, the only constitutional protection against slavery is the bit about "cruel and unusual punishment", which is _very_ open to interpretation. The constitution still allows slavery as a punishment for a crime otherwise, and I don't think it really addresses contracts of indenture. Technically speaking, it could be made a criminal offense to violate an employment contract, punishable by being forced to fulfil the employment contract. The Supreme Court might decide that the punishment was cruel and/or unusual, but I'm not so sure they would.
The next question is how severe the punishment can be for then refusing to work. Based on what I've heard out of prisons and jails where there are currently people performing slave labour in the US, they can, at the very least, put the non-compliant slave into solitary confinement and restrict them to a bread and water diet. Exactly how legal beatings are is up in the air. Prison guards are certainly allowed to use "compliance blows", pepper spray, physical restraint, etc. on prisoners who refuse to go where they're told or do what they're told. I'm not sure exactly where the courts stand on those techniques when the "where" is a workstation and the "what" is some form of labour.
N2 28 g/mol, CO 28 g/mol, CH4 16 g/mol, H2 2 g/mol, H2O 18 g/mol, He, 4 g/mol, NO 30 g/mol, Ne 20 g/mol. I'll grant you Ar 40 g/mol. I'm not sure the mass of molecules really count for this sort of thing though. Do molecules being stripped by solar wind actually stay together in such energetic conditions? We might only be able to consider the masses of individual atoms. Anyway, oxygen, either in molecular form or as single atoms, isn't exactly heavy, but it's not really that light either compared to most of the other stuff typically found in a planetary atmosphere.
To make it safe, they would have to turn it into what we currently call “flag” or “touch” Football. It would be a different sport.
Or they could go the rugby route and just get rid of all that padding. There would be a modest increase in severe, acute injuries, and a drastic decrease in these long term ones. This would largely be based on the players learning not to use their heads as weapons.
Millions of years are an eyeblink in geologic terms. The chances of being hit tomorrow are not nil. They are very small, but it's a virtual certainty that it will happen again. At that point, unless we have the capability to either stop the piece of rock, or to escape it, we may be doomed. Stopping it or escaping it both require a healthy presence in space.
Go look at the history of the space program, and how something as simple as a person eating dinner and taking a shit afterward had to be rethought from the ground up to work in zero-gravity.
Yep. Using a wet/dry vac as a toilet really was just an unimaginable adaptation. Eating pureed food out of tubes and drinking out of spill proof cups, there's another one. Turns out that now, for the most part, they just send up regular food with a review process beforehand and tell the astronauts not to be messy eating it.
It also assumes lead/concrete shielding is the only option
Very true. If, for example, you're setting up a Mars colony, you need to take a lot of supplies and equipment with you. All those supplies and equipment would make great shielding.
Temperatures on Mars aren't really much worse than Antarctica. Also, since the Martian atmosphere is so thin, there's a lot less heat transfer to the atmosphere through conduction and convection. So, for all practical purposes, you can think of Mars as actually being a lot warmer than Antarctica.
If their real innovation was their control scheme, then it is truly amazing that they managed to get all the glory. Their control scheme was a disaster and wasn't adopted by anyone. At least, not by anyone who didn't kill themselves trying to fly.
You are right that there was a race on to achieve manned powered flight at the time. There were also many dissenters well before the Wright brothers flew. There were those who insisted that it was impossible, and those who insisted that humans would be physiologically incapable of surviving (getting back on the topic of the actual article) and those who simply insisted that it shouldn't be tried for their own bizarre contrarian reasons. Nevertheless, powered heavier than air flight succeeded.
The same kinds of dissent sprang up around spaceflight. There were claims that rockets wouldn't work in a vacuum, that humans couldn't survive the acceleration, or weightlessness, or space radiation, etc. Somehow, the naysayers generally seem to be proven wrong.
As the GP said, you're clearly trying to speak authoritatively on a topic about which you clearly know nothing, or at least very little. Your information is certainly well out of date at the very least. After all, you write: "I am aware of the *possible* existence of even smaller trace amount of water ice on the moon.". Either you don't know what a trace amount is, or you haven't heard about the results of Chandrayaan-1, which strongly suggest millions of tons of water ice in shadowed craters on the moon. Sure, if you averaged it out over the whole moon, it would probably only be a trace amount, but you don't get to call it a trace amount unless it actually is spread out. It's certainly not a meaningless amount of water for even a very large colonization effort. Mars is almost certainly a better target, however.
Pretty much all recent evidence strongly suggests that you're completely wrong about Mars having only trace amounts of water. Soil is very complex, but it can still be made. All those complex organics you mention come from organic processes. You can start with small amounts of soil, or organics grown without soil and compost them to create soil. As for nitrates not being available on Mars, it's theorized that there should be plenty of nitrates on Mars fixed through meteorite bombardment.