Replying to my own comment here just to comment on the moderation. Someone tacked on a -1 Flamebait to my post. I'm curious if anyone can tell me what part of my post was flamebait? Is it the suggestion that the police would have shot him if he had a gun? That seems perfectly reasonable to me.
Possible, sure. Practical for a small colony, no. A geosynchronous orbit on Mars is about 17,000 km from the surface. No practical space mirror is going to be able to focus light on any usefully small area from that kind of distance. The only way you could do it is to make it incredibly gigantic. If you have terraforming in mind, then that could work. If you just want to provide extra light to a small colony, it won't really work. Closer orbits could shine light into a relatively tightly focused area around the colony, but only for a small fraction of the day as they pass overhead. So, for that to work, you would need lots of space mirrors. Directly on the ground, you can concentrate light just fine with a number of different designs and cheap, lightweight reflective films.
If my observations of typical reality shows hold true, then what happens is that the ratings go through the roof. The biggest sellers in that sort of entertainment seem to be sex and human tragedy.
In any case, if a Martian colonist is dying a very public death of cancer far from help, maybe it will help people to think about all the people who die from disease _right here on Earth_ who simply don't get help. Maybe it can be turned into a net positive.
Also, if it has "only a small chance of being cured on Earth", that means that the colonist is going to be scarcely any worse off than they would be on Earth anyway.
Project Gnome was an experiment to create such a cavern in a salt deposit. There's a photo of someone standing in one of those caverns in the link. Considering the instability of such caverns, the guy in that picture has to be pretty brave. The Wikipedia article on Underground Nuclear Testing talks about these caverns. The process is well enough understood that they have specific names for the zones that form in the rock around the melt cavity: "crushed zone", "cracked zone" and "zone of irreversible strain". Overall, they don't sound like great places to live if you like surviving.
Insolation on Mars is 44% of insolation on Earth based on the distance from the sun. However, the differing conditions on Earth and Mars push that up to effectively 60% of the insolation on Earth. This is mostly due to the light atmosphere and lack of sun-blocking weather. Even in the harshest dust storms, virtually all of the light still reaches the ground.
Basically, plant growth won't be as great as the equator, but it won't be as bad as Antarctica either. Ground-based solar concentrators and maybe grow lights (either nuclear powered, or maybe even solar powered as paradoxical as that seems) could improve that even more.
You pointed out yourself that the atmosphere is 3% nitrogen. Even though that makes the concentration of nitrogen only about.025% of the concentration on Earth, there's still a massive amount of it available. It's just a matter of choosing the most reliable/energy efficient method to extract and compress it. Whether that's using custom zeolites filters or cryogenic methods or chemical/biological methods is still up in the air, but it's clear that colonists won't have trouble actually finding nitrogen, they will just need the right equipment to extract it and sufficient energy.
I have to take issue with the "ridiculous infatuation" statement. It's unfair and, frankly, a little cruel. It's not a "ridiculous infatuation", it's part of a genetic feedback loop. Heterosexual men don't have such "ridiculous infatuations" because they're childish or because they're bad people or anything like that, they have them because they're heterosexual males. Heterosexual males who don't have such infatuations generally have a serious psychological problem.
I remember hearing this nonsense from teenage girls about male erections when I was a teenager. Acting as if teenage boys are jerks for getting erections. Any typical male who has been through puberty knows that erections during those years just happen. Sometimes from sexual arousal that can be controlled through mental discipline, yes. Maybe half the time. The other half it just happens at random without any apparent stimulus and no amount of willpower will stop it. Resenting teenage boys for getting erections is akin to resenting girls for menstruating.
That said, writing juvenile things in code is something people can control. People doing it probably need to grow up and stop doing it. Of course, people getting up in arms about it likewise probably need to grow up and stop letting it bother them.
Now you know you're wrong and you're backpedalling by claiming he was reaching for his back pocket making it look like he had a gun. A simple "oops, I was wrong" would be a bit more dignified.
All right. Got me there. I think I can be forgiven a little since this was all in response to someone claiming that he had a gun that could be seen in the video and also the fact that the term "armed" pretty much never means possessing appendages in the upper torso but rather always means possessing a weapon. About the only exceptions to this seem to be when "armed is preceded" by something as in "one-armed", "hundred-armed", etc.
Jokes aside, the assertion that Rodney King was holding a gun is ridiculous on its face. Reality just doesn't support it. The very simple fact is that if a suspect has a gun and refuses to drop it, the police will not use tasers and batons, they will open fire with their own guns. That's just the way it is and, when it happens, most people have a hard time getting too upset about it. They may feel it's tragic, but they have a hard time actually blaming the officers. Beyond that, if Rodney King had been armed even with a knife the police would have been drawing as much attention as possible to that fact.
There doesn't seem to be anything in the public record of the event to support this. There's certainly no sign of these guns in the well-publicized video. Even if he had them, it doesn't somehow excuse the beating. Of course, if he actually did have guns on him and the police were aware of them, and he didn't drop them, they would have shot him rather than beaten him. This simple fact makes your claim a little dubious.
The problem basically boils down to scale. Most of us have done the experiment where you put out a candle flame with CO2, then wait for a bit, then introduce air again and the candle lights up again. It doesn't take an incredibly long time for the wick to cool enough that it won't light again, but it takes longer than intuition leads most people to believe, and a candle wick is tiny. When the heat is stored in a giant mass of coal underground, the heat can only be lost by conduction to the surrounding earth. The more you scale it up, the more 3-dimensional mass you have relative to the 2-dimensional borders where the heat is conducted away. So, if you get it hot enough to burn when there's oxygen in a large enough mass, it will stay hot enough to catch fire for decades or possibly centuries even without any oxygen getting in.
Now, if you're removing heat by pumping out gas, that's a faster way for heat to escape, but if the fires keep burning, the average temperature of the surrounding rock is going to go up and up and up and the fire is going to spread if there's flammable coal and any way for oxygen to get in. The idea seams to have the potential for uncontrollable disaster written all over it.
Of course, if you know the geology of the particular area well enough, then you can probably be pretty sure of whether or not it's even possible for it to get out of control. If you have an "island" of coal that you plan to completely burn anyway, then it's probably not an issue. Similarly, if it's already doomed to burn.
In some ways, perhaps. Certainly the availability and variety of things like food and material goods would be amazing to an ancient king (quality is a different story, that's more hit or miss). On the other hand, how many vassals do you have?
Watts measure power, not energy. Power is the rate of energy use and energy is the actual amount. Energy is measured in Joules and power is measured in Watts, which are Joules/second. 500 TW of power for one second would be 500 Terajoules. That's about eight times the energy released by the nuclear weapon that the US dropped on Hiroshima, or about one quarter the energy in a typical nuke from the US or Russian arsenals today. That would be a lot of energy. Problem is, this laser array (not a single laser) only fires for a tiny fraction of that time. The actual energy in one firing is more on the order of a walk around the neighborhood or a shot glass of gasoline to use examples that have been given by others commenting on this article.
Even with its high pressure, our sun is a very sluggish fusion reactor. At the core, the sun is said to generate about as much heat as a compost heap by unit of volume (not mass, and we're talking about material more than six times as dense as osmium). So, if we could actually replicate solar conditions, a power plant that could power the city of New York would have to weigh many times what the city itself weighs. So, we're not just competing with the conditions in the Sun, we have to do far, far better.
Actually doing it on purpose seems to be an idea fraught with risk unless it's a limited deposit and you know for a fact where all the coal runs and there's nothing above it you care about. The insulation provided by the ground is significant so unless the air can be cut off 100%, you'll probably end up with a fire you can never put out because everything stays above the flashpoint of coal all the time.
I was more thinking of places where there are already underground coal fires that they can't put out. As long as all that coal is going to burn anyway, it would be nice if you could make use of it. I don't know anything about the logistics and safety of drilling into rock that's actually on fire, however. I suppose the method you mentioned could be quite viable in coal deposits on the edge of existing coal fires. If it's not on fire now, but you know that it's inevitable it will catch fire, then you could set up the system you mentioned. I don't know much about how fire spreads underground either, of course.
Ultimately, I don't know if I consider anything to be magic. If you could give me absolute proof of fairies in the bottom of the garden who make the flowers grow, I would be amazed, but I would also consider them to be part of the natural world. I would be extremely interested in how they could be reconciled with our existing knowledge, theories and observations.
In any case, how gravity works at a fundamental level is pretty much irrelevant to the discussion. We know that gravity works and that we can know how gravity will operate in certain situations with a very, very high degree of certainty. Even if gravity actually works by tiny, invisible self-transforming machine elves linking hands and pulling, we can still be pretty sure that, in the situation we're discussing "rocks carrying massive amounts of water" were pulled to the Earth by the force we call gravity.
Sorry, right. An adjusted lens was the fix they applied to the faulty mirror, wasn't it? Maybe I was thinking of that. A bit of a monumental mess there. After they fixed it, it has been doing phenomenal work. Well worth the price.
On the contrary, the O-ring issue was quite well known, just not to the general public. The Rogers Commission report was pretty clear on that. Feynman was pretty scathing about the contractors concluding that the O-rings burning 1/3rd of the way through on previous flights constituted a "safety factor of 3". There was a flurry of concern about whether it was safe to launch in such cold temperatures before the launch precisely because of the known O-ring safety issue on the morning of the launch. It was essentially quashed for political/managerial reasons rather than engineering ones. Deciding to just risk conditions that were beyond those already known to be unsafe is not an engineering decision.
As a result, when Challenger took off, the O-ring didn't expand fast enough to fill the gap in the tang and clevis joints joining the sections of the solid booster as the joints flexed from internal pressure. Oxides from the burn filled the gap, but then were blown out during a moment of turbulence a little later in the launch. The jet of hot exhaust gases then made short work of the side of the liquid booster tank, which ruptured and ignited.
Not every part of that possible failure mode was understood before the Challenger disaster. What was known for sure is that the O-rings didn't seat properly and experienced severe damage in many previous launches and that the temperature of the O-rings at the time of launch was lower than the O-rings had been tested under. Also the fact that the O-rings and the (apparently largely useless) putty at the joints were what prevented superhot gas from spewing out of the joints.
Where did the ice come from on the asteroids? Were they hit by little wet Earths?
As you must know (or maybe not) water is made of two hydrogen atoms and one oxygen atom. By mass, that means that oxygen is 16 parts oxygen and 2 parts hydrogen. Now, hydrogen is quite simply the most abundant element (from the regular periodic table anyway, who knows if any of the dark matter takes forms that could be classed as "elements") in the entire universe. As a single proton with a single electron, it's the simplest, most basic stable form of baryonic matter. As for the oxygen, it's estimated to be the third most common element in the universe (based on the numbers from spectrographic analysis of our galaxy). There's about 1/71st as much oxygen as hydrogen by mass, which means that there's about 1/1136th as many oxygen atoms as hydrogen atoms. As such, it's not hard for h2 molecules to encounter 02 molecules. When they do so energetically enough, you end up with water. Lots and lots and lots of water. A lot of it ends up mixed up in big celestial bodies, but plenty also accumulates into smaller objects like comets and asteroids. As for the origin of the oxygen, the prevailing and well supported theory is that it was mostly made in red giant stars where four helium (mostly made during the origin of the universe) atoms combined into one oxygen atom.
I don't see the rationale for arguing about water first being seeded in conditions that are mutually exclusive from those that develop a planetary mass on a particular orbit, nor do I see any argument compelling for this, it is another "plan 9" scape-goat (to use a religious term) that says "anything unexplained happened really far away, a really long time ago".
Also, to make things clear, this article isn't really talking about all of Earth's water, it's just talking about most of its surface water. Earth has plenty of other water entrained below the surface from its first formation, and some of the surface water was doubtlessly in the early atmosphere before the planet cooled enough for surface water. Also "plan 9"? The one where humanoid aliens with really bad silver foil uniforms animate humanities dead (about three individuals worth) in order to take over the world? Ummm, huh?
Slashdot Mirror
Did he also have a Drogan's Decoder Ring?
What's an "illegal access device"? I always worry about the criminalization of tools.
Replying to my own comment here just to comment on the moderation. Someone tacked on a -1 Flamebait to my post. I'm curious if anyone can tell me what part of my post was flamebait? Is it the suggestion that the police would have shot him if he had a gun? That seems perfectly reasonable to me.
Possible, sure. Practical for a small colony, no. A geosynchronous orbit on Mars is about 17,000 km from the surface. No practical space mirror is going to be able to focus light on any usefully small area from that kind of distance. The only way you could do it is to make it incredibly gigantic. If you have terraforming in mind, then that could work. If you just want to provide extra light to a small colony, it won't really work. Closer orbits could shine light into a relatively tightly focused area around the colony, but only for a small fraction of the day as they pass overhead. So, for that to work, you would need lots of space mirrors. Directly on the ground, you can concentrate light just fine with a number of different designs and cheap, lightweight reflective films.
Sure, but there will still be billions of people around the world getting worse medical care than the colonists will.
If my observations of typical reality shows hold true, then what happens is that the ratings go through the roof. The biggest sellers in that sort of entertainment seem to be sex and human tragedy.
In any case, if a Martian colonist is dying a very public death of cancer far from help, maybe it will help people to think about all the people who die from disease _right here on Earth_ who simply don't get help. Maybe it can be turned into a net positive.
Also, if it has "only a small chance of being cured on Earth", that means that the colonist is going to be scarcely any worse off than they would be on Earth anyway.
Project Gnome was an experiment to create such a cavern in a salt deposit. There's a photo of someone standing in one of those caverns in the link. Considering the instability of such caverns, the guy in that picture has to be pretty brave. The Wikipedia article on Underground Nuclear Testing talks about these caverns. The process is well enough understood that they have specific names for the zones that form in the rock around the melt cavity: "crushed zone", "cracked zone" and "zone of irreversible strain". Overall, they don't sound like great places to live if you like surviving.
Insolation on Mars is 44% of insolation on Earth based on the distance from the sun. However, the differing conditions on Earth and Mars push that up to effectively 60% of the insolation on Earth. This is mostly due to the light atmosphere and lack of sun-blocking weather. Even in the harshest dust storms, virtually all of the light still reaches the ground.
Basically, plant growth won't be as great as the equator, but it won't be as bad as Antarctica either. Ground-based solar concentrators and maybe grow lights (either nuclear powered, or maybe even solar powered as paradoxical as that seems) could improve that even more.
You pointed out yourself that the atmosphere is 3% nitrogen. Even though that makes the concentration of nitrogen only about .025% of the concentration on Earth, there's still a massive amount of it available. It's just a matter of choosing the most reliable/energy efficient method to extract and compress it. Whether that's using custom zeolites filters or cryogenic methods or chemical/biological methods is still up in the air, but it's clear that colonists won't have trouble actually finding nitrogen, they will just need the right equipment to extract it and sufficient energy.
I have to take issue with the "ridiculous infatuation" statement. It's unfair and, frankly, a little cruel. It's not a "ridiculous infatuation", it's part of a genetic feedback loop. Heterosexual men don't have such "ridiculous infatuations" because they're childish or because they're bad people or anything like that, they have them because they're heterosexual males. Heterosexual males who don't have such infatuations generally have a serious psychological problem.
I remember hearing this nonsense from teenage girls about male erections when I was a teenager. Acting as if teenage boys are jerks for getting erections. Any typical male who has been through puberty knows that erections during those years just happen. Sometimes from sexual arousal that can be controlled through mental discipline, yes. Maybe half the time. The other half it just happens at random without any apparent stimulus and no amount of willpower will stop it. Resenting teenage boys for getting erections is akin to resenting girls for menstruating.
That said, writing juvenile things in code is something people can control. People doing it probably need to grow up and stop doing it. Of course, people getting up in arms about it likewise probably need to grow up and stop letting it bother them.
You specifically wrote:
You can't see the gun he had on him in the video
Now you know you're wrong and you're backpedalling by claiming he was reaching for his back pocket making it look like he had a gun. A simple "oops, I was wrong" would be a bit more dignified.
Whoops, accidentally replied to my own post rather than yours.
All right. Got me there. I think I can be forgiven a little since this was all in response to someone claiming that he had a gun that could be seen in the video and also the fact that the term "armed" pretty much never means possessing appendages in the upper torso but rather always means possessing a weapon. About the only exceptions to this seem to be when "armed is preceded" by something as in "one-armed", "hundred-armed", etc.
Jokes aside, the assertion that Rodney King was holding a gun is ridiculous on its face. Reality just doesn't support it. The very simple fact is that if a suspect has a gun and refuses to drop it, the police will not use tasers and batons, they will open fire with their own guns. That's just the way it is and, when it happens, most people have a hard time getting too upset about it. They may feel it's tragic, but they have a hard time actually blaming the officers. Beyond that, if Rodney King had been armed even with a knife the police would have been drawing as much attention as possible to that fact.
There doesn't seem to be anything in the public record of the event to support this. There's certainly no sign of these guns in the well-publicized video. Even if he had them, it doesn't somehow excuse the beating. Of course, if he actually did have guns on him and the police were aware of them, and he didn't drop them, they would have shot him rather than beaten him. This simple fact makes your claim a little dubious.
The problem basically boils down to scale. Most of us have done the experiment where you put out a candle flame with CO2, then wait for a bit, then introduce air again and the candle lights up again. It doesn't take an incredibly long time for the wick to cool enough that it won't light again, but it takes longer than intuition leads most people to believe, and a candle wick is tiny. When the heat is stored in a giant mass of coal underground, the heat can only be lost by conduction to the surrounding earth. The more you scale it up, the more 3-dimensional mass you have relative to the 2-dimensional borders where the heat is conducted away. So, if you get it hot enough to burn when there's oxygen in a large enough mass, it will stay hot enough to catch fire for decades or possibly centuries even without any oxygen getting in.
Now, if you're removing heat by pumping out gas, that's a faster way for heat to escape, but if the fires keep burning, the average temperature of the surrounding rock is going to go up and up and up and the fire is going to spread if there's flammable coal and any way for oxygen to get in. The idea seams to have the potential for uncontrollable disaster written all over it.
Of course, if you know the geology of the particular area well enough, then you can probably be pretty sure of whether or not it's even possible for it to get out of control. If you have an "island" of coal that you plan to completely burn anyway, then it's probably not an issue. Similarly, if it's already doomed to burn.
You mean through the Suez canal?
In some ways, perhaps. Certainly the availability and variety of things like food and material goods would be amazing to an ancient king (quality is a different story, that's more hit or miss). On the other hand, how many vassals do you have?
Watts measure power, not energy. Power is the rate of energy use and energy is the actual amount. Energy is measured in Joules and power is measured in Watts, which are Joules/second. 500 TW of power for one second would be 500 Terajoules. That's about eight times the energy released by the nuclear weapon that the US dropped on Hiroshima, or about one quarter the energy in a typical nuke from the US or Russian arsenals today. That would be a lot of energy. Problem is, this laser array (not a single laser) only fires for a tiny fraction of that time. The actual energy in one firing is more on the order of a walk around the neighborhood or a shot glass of gasoline to use examples that have been given by others commenting on this article.
Even with its high pressure, our sun is a very sluggish fusion reactor. At the core, the sun is said to generate about as much heat as a compost heap by unit of volume (not mass, and we're talking about material more than six times as dense as osmium). So, if we could actually replicate solar conditions, a power plant that could power the city of New York would have to weigh many times what the city itself weighs. So, we're not just competing with the conditions in the Sun, we have to do far, far better.
Actually doing it on purpose seems to be an idea fraught with risk unless it's a limited deposit and you know for a fact where all the coal runs and there's nothing above it you care about. The insulation provided by the ground is significant so unless the air can be cut off 100%, you'll probably end up with a fire you can never put out because everything stays above the flashpoint of coal all the time.
I was more thinking of places where there are already underground coal fires that they can't put out. As long as all that coal is going to burn anyway, it would be nice if you could make use of it. I don't know anything about the logistics and safety of drilling into rock that's actually on fire, however. I suppose the method you mentioned could be quite viable in coal deposits on the edge of existing coal fires. If it's not on fire now, but you know that it's inevitable it will catch fire, then you could set up the system you mentioned. I don't know much about how fire spreads underground either, of course.
That does make a lot more sense.
Ultimately, I don't know if I consider anything to be magic. If you could give me absolute proof of fairies in the bottom of the garden who make the flowers grow, I would be amazed, but I would also consider them to be part of the natural world. I would be extremely interested in how they could be reconciled with our existing knowledge, theories and observations.
In any case, how gravity works at a fundamental level is pretty much irrelevant to the discussion. We know that gravity works and that we can know how gravity will operate in certain situations with a very, very high degree of certainty. Even if gravity actually works by tiny, invisible self-transforming machine elves linking hands and pulling, we can still be pretty sure that, in the situation we're discussing "rocks carrying massive amounts of water" were pulled to the Earth by the force we call gravity.
Sorry, right. An adjusted lens was the fix they applied to the faulty mirror, wasn't it? Maybe I was thinking of that. A bit of a monumental mess there. After they fixed it, it has been doing phenomenal work. Well worth the price.
On the contrary, the O-ring issue was quite well known, just not to the general public. The Rogers Commission report was pretty clear on that. Feynman was pretty scathing about the contractors concluding that the O-rings burning 1/3rd of the way through on previous flights constituted a "safety factor of 3". There was a flurry of concern about whether it was safe to launch in such cold temperatures before the launch precisely because of the known O-ring safety issue on the morning of the launch. It was essentially quashed for political/managerial reasons rather than engineering ones. Deciding to just risk conditions that were beyond those already known to be unsafe is not an engineering decision.
As a result, when Challenger took off, the O-ring didn't expand fast enough to fill the gap in the tang and clevis joints joining the sections of the solid booster as the joints flexed from internal pressure. Oxides from the burn filled the gap, but then were blown out during a moment of turbulence a little later in the launch. The jet of hot exhaust gases then made short work of the side of the liquid booster tank, which ruptured and ignited.
Not every part of that possible failure mode was understood before the Challenger disaster. What was known for sure is that the O-rings didn't seat properly and experienced severe damage in many previous launches and that the temperature of the O-rings at the time of launch was lower than the O-rings had been tested under. Also the fact that the O-rings and the (apparently largely useless) putty at the joints were what prevented superhot gas from spewing out of the joints.
Where did the ice come from on the asteroids? Were they hit by little wet Earths?
As you must know (or maybe not) water is made of two hydrogen atoms and one oxygen atom. By mass, that means that oxygen is 16 parts oxygen and 2 parts hydrogen. Now, hydrogen is quite simply the most abundant element (from the regular periodic table anyway, who knows if any of the dark matter takes forms that could be classed as "elements") in the entire universe. As a single proton with a single electron, it's the simplest, most basic stable form of baryonic matter. As for the oxygen, it's estimated to be the third most common element in the universe (based on the numbers from spectrographic analysis of our galaxy). There's about 1/71st as much oxygen as hydrogen by mass, which means that there's about 1/1136th as many oxygen atoms as hydrogen atoms. As such, it's not hard for h2 molecules to encounter 02 molecules. When they do so energetically enough, you end up with water. Lots and lots and lots of water. A lot of it ends up mixed up in big celestial bodies, but plenty also accumulates into smaller objects like comets and asteroids. As for the origin of the oxygen, the prevailing and well supported theory is that it was mostly made in red giant stars where four helium (mostly made during the origin of the universe) atoms combined into one oxygen atom.
I don't see the rationale for arguing about water first being seeded in conditions that are mutually exclusive from those that develop a planetary mass on a particular orbit, nor do I see any argument compelling for this, it is another "plan 9" scape-goat (to use a religious term) that says "anything unexplained happened really far away, a really long time ago".
Also, to make things clear, this article isn't really talking about all of Earth's water, it's just talking about most of its surface water. Earth has plenty of other water entrained below the surface from its first formation, and some of the surface water was doubtlessly in the early atmosphere before the planet cooled enough for surface water.
Also "plan 9"? The one where humanoid aliens with really bad silver foil uniforms animate humanities dead (about three individuals worth) in order to take over the world? Ummm, huh?