While it's true that many Republicans favor changing the voting system one way and Democrats the other way, it is more than a little dishonest to imply that that means that each system is equally political, the demon of false-equivalency rears its head again. Indeed, you say that the Democratic plan is "an even more blatant attempt to rig the system" but I don't really understand how you can define a National Popular Vote as "rigging the system", especially in comparison to the alternatives.
If you look at the sorts of scenarios that each system allows, you can see that a National Popular Vote is inherently impossible skew and manipulate (ignoring voter fraud, which all systems are equally vulnerable to). There is simply no "worst-case" scenario for a NPV, the candidate with the most votes wins. There are cases where the result is different than it would be under the historical system, but no cases that are obviously un-representative. Take the current system, where a plurality in most states gets that candidate the entire block of votes. You could conceivable have a candidate win in a landslide despite getting dramatically less than a majority nationally. Under the district by district system, which will probably typically be more representative, you still have many cases, like Pennsylvania, where a state with a strong majority scrapes up a minimum level of electoral votes, that worst-case is even more drastic, with a Presidential candidate potentially winning by even more of a landslide with even fewer votes.
National Popular Vote has even more benefits as well, letting us concentrate on the nation instead of a privileged few. As one example, a few hundred thousand people in Miami will no longer drive foreign policy with an entire nation.
No current or near future laser will do anything to the warhead itself. The warhead is designed to survive high speed reentry, good luck to make a laser that can exceed that energy release.
You are assuming that the parent is talking about ICBMs, which are the only missiles which have to survive any sort of reentry. Any shorter range land/air/water to land missile would have no reentry shield whatsoever. That's not to say that such shielding couldn't be installed, but it may very well be worthwhile to force your opponent to replace (completely arbitrary) 10% of their explosive payload with a heat shield.
Additionally, your impression of ICBMs is incorrect, in three big ways:
First of all, they do not have to survive high speed reentry, but low speed reentry, as they are not re-entering from an orbit, but from sub-orbital flight. Depending on the trajectory the reentry speed of an ICBM will vary from 4 to 7 km/s. We'll say 7, for the longest ranged missiles. The Apollo spacecraft are actual high-speed reentry craft, coming in at 11 km/s. While the maximum temperature a craft will sustain on reentry is linear with reentry speed, the total heat is based on the square, so Apollo entry speeds need to absorb nearly two and half times the heat.
Secondly, the materials which are used to create such heat shields are ablative, which means that the protective power of the shield is used up on reentry. While there is obvious difficulty in getting through the safety factor of an ablative heat shield it's still at depleted strength.
Lastly, in most modern ICBMs, the reentry stage is nowhere near the payload at close approaches. Instead the reentry stage deploys a whole host of goodies, chaff, decoys, multiple payloads, targeting aids, etc. At this point you are back to installing special heat shields on your payload, at the expense of yield.
Note that I don't mean to imply that an end-of-flight intercept is preferable or even similar to a launch intercept from a technical standpoint. The missile is going much slower shortly after launch, and the energy input required to ignite the fuel is much less than other kill scenarios. However, you exaggerate the difficulties of an end-of-flight intercept. Also, while an end-of-flight intercept is technically harder, it has the practical benefit of not requiring line of sight to the launch site at the launch time. If we ignore the requirements for being in the correct position to intercept the missile, then the simplest technical solution is to cut the fuel lines.
None of those reference the fact that in this case the "secret" technology is one that their main competitor already has. In that case the response to conceal your own program is "Wow, this actually works." If you instead respond with "Pssh, this doesn't work. Like, at all. Man, you'd have to be preeeettyyy dumb to try to build a spaceship with this engine, which we haven't, because we're smart." then your operational security may be hampered a bit.
Phantom Works just said they're not working with Shawyer. They didn't say the drive doesn't work. Given their nature, if the drive did work, they wouldn't disclose that because it would have profound advantages for classified work (e.g. KH-11/KH-12/etc. spy satellite maneuvering).
No, they would disclose that the device worked regardless of classified work, because China already has the drive and the designer of the drive. The only reason to lie about something like this working is to dissuade other powers from trying it themselves. When China gets it first, and knows that it works, and then America says it doesn't work, the Chinese know the Americans have something to hide. What's more, then all of China's military and civilian satellite have super awesome propulsion, and American civilian satellites get crummy propulsion.
So if Boeing says it doesn't work, either they got a broken engine, or it just doesn't work. (And given that this engine is theoretically impossible I'm betting on "It doesn't work".)
American insurance typically involves the patient paying part of the fee, usually 10-40 dollars depending on the service. It is to discourage us from going to the doctor when there's nothing wrong with us.
Yep. What foreigners don't realize is that taking time out of your day to go hang out in a waiting room and then sit uncomfortably and be poked and prodded is one of our favorite American activities. Videogames? Football? Baseball? Concerts? Sex? None compare to the joy of a visit to the Doctor. If our healthcare system didn't force us to pay admission for the pleasure I don't think any of us would ever do anything else.
In this Astrophysicists professional opinion it is unlikely (and probably impossible) to construct a rigid "shell" structure which is able to hold itself over the sun, or even hold itself apart from it's own gravity field before collapsing into rubble (as another poster stated). If you did construct such a structure it would also be unstable and prone to falling into the sun, ala Ringworld, but if you could construct such a structure in the first place that may not be an issue.
The simple fact is that the stiffness/density ratio to withstand the gravity of a sun is enormous, probably impossibly so. Also, that sort of structure would probably have an enormous mass.
A very popular way of solving this is the "Dyson Swarm", which other posters have mentioned. Just keep building and launching normal satellites until they literally block the sun. An alternative (one which is not mutually exclusive to the swarm approach) is to build a structure that does not need to withstand gravity. Instead of a shell build a thin membrane that surrounds the sun, light enough that the solar radiation pressure that object feels is slightly larger than the gravitational pressure. Instead of tending to fall into the sun the entire balloon would inflate out from the sun until it was taut. The structure would then only have to withstand the tensile force of the excess solar radiation pressure, so lets say 1% of the gravitational force, and tensile force can be withstood with lighter materials than compressive force to boot.
So what would the areal density of such a membrane have to be?:
Pressure = FluxDensity / c (assuming that our membrane is perfectly absorptive, also note that we don't need to take into account the pressure of the photons leaving the membrane, as they will be split evenly between the inner and outer surfaces and cancel each other out.)
FluxDensity = SolarLuminosity / MembraneArea (//*The SolarLuminosity is the total power output of the sun.)
MembraneArea = 4 * pi * radius^2
so: ArealDensity = (TotalPowerOutputOfSun / (4 * pi * radius^2) / c) / (SunMass * GravitationalConstant / radius^2)
The radius cancels out! That means that the same membrane (barring heat constraints) can be used anywhere in the solar system!
ArealDensity = (TotalPowerOutputOfSun) / (4 * pi * SunMass * GravitationalConstant * c)
ArealDensity = (3.839E26 Watts (kg*m^2/s^3)) / (4 * pi * 1.9891E30 kg * 6.673E-11 m^3/kg/s^2 * 3E8 m/s)
ArealDensity = 7.67E-4 kg/m^2
So all we need to do is make a very thin structural membrane, line it with incredibly efficient solar cells, as well as efficient transmission to the laser stations studded every few tens of thousands of square kilometers, into a sheet of membrane that masses around 7 grams a square meter! (safety factor, as well as extra to hold up those laser installations) Easy peasy, that's just an order of magnitude less than a sheet of ordinary paper! For an even more relevant example this paper references a current deployed solar array areal density of 80 g per square meter. Coincedentally enough that's actually exactly the areal density of a sheet of paper, so an order of magnitude of improvement is actually what we are trying to achieve.
As far as the total mass of this system, that's ArealDensity * 4 * pi * radius^2. Let's think really grand and build it 10% past Saturn..0007 * 4 * pi * (1.1 * 1.43E9)^2 = 2.18E16 kg. That's only 3.6E-9 the mass of our planet, or 2.3E-5 the mass of Ceres, so once we get Asteroid mining started up that'll be no problem. Heck, if you wanted to be lame and build it at 1.1 times Earth's maximum distance from the sun you could make it more than 100 times lighter than the Saturn variant.
You bring your opponent over to your point of view and they agree with your superior logic and evidence.
You are brought over to your opponents position and agree with their superior logic and evidence.
Unless I am mistaken, you haven't listed two way to win an argument; you've listed one way to win and one way to lose. These don't even exhaust the ways there are to end an argument.
There actually are two ways to win an argument, namely
(1)You bring your opponent over to your point of view and they agree with your superior logic and evidence.
(2) You bring your opponent over to your point of view through some logically irrelevant means.
The number of irrelevant means are endless: wear him down, make him feel stupid, encourage him to jump on the bandwagon... the list goes on.
GP is correct, those are the only two ways to win the argument. You do list several ways to end an argument, but, for example, neither of you "wins" if you simply wear him down such that he doesn't agree with you but just wants you to shut up.
If during the course of the argument you decide that your "opponent" was right then you have both won. You now have more knowledge and/or wisdom than you had before, which is the closest thing to a win such a discussion can ever have. Your "opponent" wins as well, as his position has been vindicated, and he may have learned something or gotten more food for thought along the way.
It is terrible to view the "opponent" being correct as a loss. Humans hate to lose, if someone feels like their "opponent" being right will lead to them losing then the solution is simple: buckle down and find a way to convince yourself the other party is wrong. There are many ways to lose an argument, but being wrong and not realizing it at the end is close to the worst. The worst is being wrong and convincing the other party that you are right. A naive or overly competitive person will view this as winning, in truth that is a terrible loss for each of you.
That would be an interesting next step to take. When I took my first CS class I put my own spin on the Game of Life, it was still an orthogonal board, but with two species, Cows and Wolves, with different propagation rules. You could make some interesting gliders with them, the Wolves appeared to chase the Cows.
According to the human players, poker is largely about mind games.
Really? The pros I have heard have spoken about probabilities, trying to determine your opponents' strategies (are they betting conservatively? do they bet on weaker hands more frequently than expected?), and measuring expected returns quickly. Tells and psychology seem to be a small part of their strategy, and unsurprisingly, professional poker players defeat the AI players despite the fact that computers have no psychology to play against.
"Trying to determine your opponents' strategies" is a portion of that mind game. The fact that professional human beings continually smoke current AIs is an strong indicator that psychological ploys are at work. If the game was all about probabilities then the computers would destroy human beings every time. As you say, the computers have no psychology to play against, they are generally predictable, and do not have the algorithms to judge character, intent, motivation (aka the psychological mind games) that would let them in turn predict the human's actions.
The sort of strategy you mentioned, determining whether a player is more likely to bluff with a weak hand, is exactly the sort of thing that will get an AI to lose their money once the human changes their strategy partially through the game, whether for a big hand, or over time just to throw off the other players.
Al Awlaki was killed in Yemen, after the Yemeni government ordered him captured dead or alive, right? You need a better example than this for bashing the US.
http://en.wikipedia.org/wiki/Anwar_al-Awlaki
Ah ok, so once you are convicted in Yemen the US military can be used to carry out the sentencing? Interesting, I didn't realize that this country worked for Yemen. Honestly though, I'm relieved. I used to think that the US was responsible for all of their actions around the world, and it made me pretty ashamed. Now I can just say "Sorry guys, we know this looks bad, but our hands are tied, Yemen told us to do this."
Whoo-hoo-hoo, look who knows so much. It just so happens that your friend here is only mostly dead. There's a big difference between mostly dead and all dead. "Mostly dead", is "slightly alive". With "all dead", well, with all dead, there's usually only one thing you can do.
Who wants to bet that the top of the list of "flagged" sites will be comprised of EU government and law enforcement sites? I guess we'll only know for sure if they refuse to release a list of the top sites flagged. In fact, I dare say that the list will be so cluttered with joke flaggings that it will be difficult to determine what, if any, sites identified are actually "inciting terrorism" (not helped by the fact that one man's terrorist is another man's political leader).
You are incorrect in thinking that those are false positives. Every single flag is guaranteed to find a terrorist, the site being flagged, or the person doing the flagging. Obviously if you are going to sabotage their intelligence gathering with protests against Big Brother you must be one of Them.
A few boats might take damage or even be sunk, but I'd hardly think that the whole fleet would be in collectively in jeopardy.
The concern isn't that the entire fleet would be destroyed. As you have conceded, a few of our ships "might take damage or even be sunk". That's a pretty tremendous victory for Iran if that happens. Best case scenario they get a Ticonderoga class Cruiser, which costs about a billion dollars (although we haven't been building them for 27 years, so I'm not sure how we'd actually replace it). We may lose an Arleigh Burke instead, which Wikipedia places at $1.8 billion. If Iran can accomplish that with a couple million dollars in boats and rockets than that's an amazing upset.
Carriers seem like an awfully good projection of power for an immediate (less than 12 hours) retaliation, but round trip from the USA to Iraq and back is only 30-50 hours these days (by bomber).
I think it's an open question whether or not that sort of tactic is effective by itself, especially against a larger opponent. Keep in mind that there are only 19 B-2s ready for combat (the other active B-2 is used for testing purposes) and they average 119 man hours of maintenance per hour of flight, so each B-2 will only be flying once every 5-6 days tops. That's just not a lot of bombs dropping, especially if you are fighting over multiple fronts so that all of your centrally located aircraft now have a much larger area to cover.
That said the B-2 isn't the only long-range bomber like that, you also have the B-1 and the B-52, so once you add those in you may indeed be overshadowing what your aircraft carriers are able to field, especially because each of those planes can be fielded from alternative positions like Germany, giving a much smaller roundtrip.
I still think that you can't beat carriers for their addition of many, many smaller yet capable planes that are able to respond much quicker, loiter better because they are based closer, etc.
I'd guess the plane-carried ABM lasers could fry a satellite in actual Star Wars style as well, if that program happened to be funded by whatever administration was in charge during the war - that's some really impressive technology.
The technology necessary to fry a satellite is much less impressive, and much older, than the sort of lasers we are finally seeing today. The plane-carried ABM lasers needed to be portable (obviously) because they needed to be carried where they could target the launch sites, where the ICBM is still slow and has lots of propellant to catch on fire. In order to get a high-powered laser in a package a (very large) plane would carry they use chemical based lasers that produce very high power pulses but have a limited number of shots.
Frying a GPS satellite is a lot easier, you do it from a ground station, so you have access to way more power and larger machinery (if you wanted to take out a satellite over China, and not over you then you'd need to put this on a ship or something), and you don't need a high-powered laser. We aren't vaporizing anything, we're just gently warming it. When people think lasers they are thinking something like this recent video, where a laser melts through a car hood and (supposedly) the engine underneath. That's totally overkill for what you need though, the boiling temperature of aluminum is 2467 degrees Celsius, heating a satellite to a hundred degrees Celsius would be more than enough, and while that takes more energy than the above video shows (larger mass being heated) it takes way less power, because you don't need to do it in two seconds, three hours is fine.
You actually don't need a laser at all, really any spectrum of light you throw out there will do. An old (in both senses of the word) coworker of mine told me that one of the Apollo missions was landing near an existing instrument on the moon that transmitted on the same frequency of one of the Apollo commands. They didn't have the ability to remotely turn off the device so they just pointed a very powerful antenna at it and broadcast noise until they were sure it was dead. No citation for that unfortunately, but I would love one if someone else knows of this.
Not really a concern - the US can certainly shoot down all the satellites it wants to. Those in lower orbits like GPS and spy sats can be taken down by (relatively) cheap missiles launched from a jet at high altitude. They'd all be gone in the first few hours of a real war.
Our GPS Satellites are in Lower Earth Orbits. These BeiDou satellites are in Geosynchronous orbits, far outside of our missile range, and possibly for exactly this reason. Keep in mind that in that "real war" the process of destroying the few dozens of enemy satellites you want to destroy will produce enormous debris clouds through LEO, possibly destroying yet more satellites and causing yet more debris clouds. This sort of has a MAD effect, as such a shooting war could wipe out most of the planet's LEO real estate. However, if one party doesn't have hardly any assets in LEO, this stops being much of a concern for them, it's sort of like if the US or Russia had developed an impervious ICBM shield at the height of the cold war.
Unfortunately for the US, not only is China starting out their space infrastructure in higher orbits, but the Russians have done this for decades as well. Ever since the Space Shuttle came around with the capability of grabbing LEO satellites and bringing them back down for analysis the Russians started putting their Top Secret military satellites up in higher orbits where the Space Shuttle couldn't get them. Now they aren't as vulnerable to a Space Debris Doomsday scenario either.
However, just because we can't hit GEO sats with missiles doesn't mean we can't destroy them. Satellites are very thermally sensitive due to how difficult it is to dump heat in space, and by definition GEO sats don't move with respect to the Earth much, so it's theoretically pretty easy to destroy them with lasers. And I don't mean vaporizing them with Star Wars lasers, I mean shining a high power laser on them for several minutes or hours and slowly adding more heat to the satellite than it can dump. Hard to do this to a LEO, (from a single ground station) you'll only get a shot at it for five or six minutes at a time, and it'll have its entire 90 minute orbit to cool off again, but you can shoot at a GEO forever.
I thought it would be about a constitutional right to keep and bear DDOS systems and pen test tools.
Yeah, I too was expecting a discussion of the sorts of encryption, malware, etc that should be understood to be defined as "arms" in the modern world, and which of them should be considered to fall under the second amendment.
The telescope is "seeing" the planet as it was 946 years ago... maybe it's not even there any longer
I know, planets these days are always picking up and vanishing without even saying good bye. First Ceres, then Pluto. Every morning I wake up I breathe a sigh of relief that the Earth is still here.
But by that logic, leading a sedentary lifestyle will lead to long life. Everyone is different and some people put on muscle mass way faster than others, just from their natural genetics. Being able to put muscle on easier than average is far from a sure ticket to a heart attack.
So you are saying that either hulked out mutated muscles are the healthiest way to live, or a sedentary person that never moves a muscle is the healthiest way to live?
No room in your hypothesis for a middle ground that doesn't go all the way to one enormous extreme being the best?
So why is NASA spending $2.5B on the next Mars Rover and planning to spend over $6B more on a Mars sample return when it can't find the money for much cheaper missions to Europa or Enceladus?"
This summary doesn't accurately describe the situation at all. The Mars missions are so more expensive largely because they are doing more. The next Mars Rover is going to be larger, heavier, and more capable than the two previous--wildly successful--rovers in pretty much every way. That $6B mission is a sample return mission, lifting off and bringing a research payload from Mars back to Earth is an enormous technical challenge. It's never been done before and that will drive most of the cost.
Also the linked missions aren't quite as cheap as the summary implies. The proposed mission to Europa has an estimated cost of $2.5 billion (and $4.7 billion is the given estimate in the last paragraph of the first link in the summary), exactly the same price as the first "overly expensive" Mars mission mentioned. The Enceladus trip is much cheaper, estimated at a little over half of a billion, so that at least is a reasonable alternative, though I still want to point out that that mission is much earlier in the planning stages, and missions that diverge a lot from previous missions are more likely to have ballooning costs as new found kinks are worked out.
Another issue is that not only are the Mars missions promising more, but there is a much greater chance that they will be able to live up to those promises. Every single Mars mission we've done so far has added to our body of knowledge on the planet, and our ability to better plan a mission and engineer a craft that can get more and better data on the next run. From Viking and on we have answered many, many questions about Mars, and learned about even more questions (meaning that we know the sort of doodad that needs to be on the next mission to answer that new question). Starting a new series of missions to a new celestial body means that in a lot of ways you have to start back at the drawing board again. This is another reason to start small on a new body, better to have 3-4 partially successful $200 million missions leading up to that big $2.5 billion dollar rover mission rather than trying plan a $2.5 billion mission right of the bat.
I should clarify that I don't think that investigating these moons is a bad idea. I think it's a wonderful one. However I don't think that we should investigate these moons in place of Mars, when we have already accumulated so much experience on how to investigate Mars. It's also worthwhile to note that this was the viewpoint of every scientist interviewed in the article. Nobody said that they didn't want to go to Mars, they all said that they wanted this moons visited in addition to Mars, not instead of.
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While it's true that many Republicans favor changing the voting system one way and Democrats the other way, it is more than a little dishonest to imply that that means that each system is equally political, the demon of false-equivalency rears its head again. Indeed, you say that the Democratic plan is "an even more blatant attempt to rig the system" but I don't really understand how you can define a National Popular Vote as "rigging the system", especially in comparison to the alternatives.
If you look at the sorts of scenarios that each system allows, you can see that a National Popular Vote is inherently impossible skew and manipulate (ignoring voter fraud, which all systems are equally vulnerable to). There is simply no "worst-case" scenario for a NPV, the candidate with the most votes wins. There are cases where the result is different than it would be under the historical system, but no cases that are obviously un-representative. Take the current system, where a plurality in most states gets that candidate the entire block of votes. You could conceivable have a candidate win in a landslide despite getting dramatically less than a majority nationally. Under the district by district system, which will probably typically be more representative, you still have many cases, like Pennsylvania, where a state with a strong majority scrapes up a minimum level of electoral votes, that worst-case is even more drastic, with a Presidential candidate potentially winning by even more of a landslide with even fewer votes.
National Popular Vote has even more benefits as well, letting us concentrate on the nation instead of a privileged few. As one example, a few hundred thousand people in Miami will no longer drive foreign policy with an entire nation.
No current or near future laser will do anything to the warhead itself. The warhead is designed to survive high speed reentry, good luck to make a laser that can exceed that energy release.
You are assuming that the parent is talking about ICBMs, which are the only missiles which have to survive any sort of reentry. Any shorter range land/air/water to land missile would have no reentry shield whatsoever. That's not to say that such shielding couldn't be installed, but it may very well be worthwhile to force your opponent to replace (completely arbitrary) 10% of their explosive payload with a heat shield.
Additionally, your impression of ICBMs is incorrect, in three big ways:
First of all, they do not have to survive high speed reentry, but low speed reentry, as they are not re-entering from an orbit, but from sub-orbital flight. Depending on the trajectory the reentry speed of an ICBM will vary from 4 to 7 km/s. We'll say 7, for the longest ranged missiles. The Apollo spacecraft are actual high-speed reentry craft, coming in at 11 km/s. While the maximum temperature a craft will sustain on reentry is linear with reentry speed, the total heat is based on the square, so Apollo entry speeds need to absorb nearly two and half times the heat.
Secondly, the materials which are used to create such heat shields are ablative, which means that the protective power of the shield is used up on reentry. While there is obvious difficulty in getting through the safety factor of an ablative heat shield it's still at depleted strength.
Lastly, in most modern ICBMs, the reentry stage is nowhere near the payload at close approaches. Instead the reentry stage deploys a whole host of goodies, chaff, decoys, multiple payloads, targeting aids, etc. At this point you are back to installing special heat shields on your payload, at the expense of yield.
Note that I don't mean to imply that an end-of-flight intercept is preferable or even similar to a launch intercept from a technical standpoint. The missile is going much slower shortly after launch, and the energy input required to ignite the fuel is much less than other kill scenarios. However, you exaggerate the difficulties of an end-of-flight intercept. Also, while an end-of-flight intercept is technically harder, it has the practical benefit of not requiring line of sight to the launch site at the launch time. If we ignore the requirements for being in the correct position to intercept the missile, then the simplest technical solution is to cut the fuel lines.
See my other replies http://science.slashdot.org/comments.pl?sid=3443657&cid=42829549 and http://science.slashdot.org/comments.pl?sid=3443657&cid=42840735
None of those reference the fact that in this case the "secret" technology is one that their main competitor already has. In that case the response to conceal your own program is "Wow, this actually works." If you instead respond with "Pssh, this doesn't work. Like, at all. Man, you'd have to be preeeettyyy dumb to try to build a spaceship with this engine, which we haven't, because we're smart." then your operational security may be hampered a bit.
Phantom Works just said they're not working with Shawyer. They didn't say the drive doesn't work. Given their nature, if the drive did work, they wouldn't disclose that because it would have profound advantages for classified work (e.g. KH-11/KH-12/etc. spy satellite maneuvering).
No, they would disclose that the device worked regardless of classified work, because China already has the drive and the designer of the drive. The only reason to lie about something like this working is to dissuade other powers from trying it themselves. When China gets it first, and knows that it works, and then America says it doesn't work, the Chinese know the Americans have something to hide. What's more, then all of China's military and civilian satellite have super awesome propulsion, and American civilian satellites get crummy propulsion.
So if Boeing says it doesn't work, either they got a broken engine, or it just doesn't work. (And given that this engine is theoretically impossible I'm betting on "It doesn't work".)
Some people find whoring to be an unacceptable option.
Especially when they have the flu, that will definitely spread the disease.
American insurance typically involves the patient paying part of the fee, usually 10-40 dollars depending on the service. It is to discourage us from going to the doctor when there's nothing wrong with us.
Yep. What foreigners don't realize is that taking time out of your day to go hang out in a waiting room and then sit uncomfortably and be poked and prodded is one of our favorite American activities. Videogames? Football? Baseball? Concerts? Sex? None compare to the joy of a visit to the Doctor. If our healthcare system didn't force us to pay admission for the pleasure I don't think any of us would ever do anything else.
In this Astrophysicists professional opinion it is unlikely (and probably impossible) to construct a rigid "shell" structure which is able to hold itself over the sun, or even hold itself apart from it's own gravity field before collapsing into rubble (as another poster stated). If you did construct such a structure it would also be unstable and prone to falling into the sun, ala Ringworld, but if you could construct such a structure in the first place that may not be an issue.
The simple fact is that the stiffness/density ratio to withstand the gravity of a sun is enormous, probably impossibly so. Also, that sort of structure would probably have an enormous mass.
A very popular way of solving this is the "Dyson Swarm", which other posters have mentioned. Just keep building and launching normal satellites until they literally block the sun. An alternative (one which is not mutually exclusive to the swarm approach) is to build a structure that does not need to withstand gravity. Instead of a shell build a thin membrane that surrounds the sun, light enough that the solar radiation pressure that object feels is slightly larger than the gravitational pressure. Instead of tending to fall into the sun the entire balloon would inflate out from the sun until it was taut. The structure would then only have to withstand the tensile force of the excess solar radiation pressure, so lets say 1% of the gravitational force, and tensile force can be withstood with lighter materials than compressive force to boot.
So what would the areal density of such a membrane have to be?:
Pressure * MembraneArea = MembraneMass * Gravity
MembraneMass/MembraneArea = ArealDensity = Pressure / Gravity
Gravity = SunMass * GravitationalConstant / radius^2
Pressure = FluxDensity / c (assuming that our membrane is perfectly absorptive, also note that we don't need to take into account the pressure of the photons leaving the membrane, as they will be split evenly between the inner and outer surfaces and cancel each other out.)
FluxDensity = SolarLuminosity / MembraneArea (//*The SolarLuminosity is the total power output of the sun.)
MembraneArea = 4 * pi * radius^2
so: ArealDensity = (TotalPowerOutputOfSun / (4 * pi * radius^2) / c) / (SunMass * GravitationalConstant / radius^2)
The radius cancels out! That means that the same membrane (barring heat constraints) can be used anywhere in the solar system!
ArealDensity = (TotalPowerOutputOfSun) / (4 * pi * SunMass * GravitationalConstant * c)
ArealDensity = (3.839E26 Watts (kg*m^2/s^3)) / (4 * pi * 1.9891E30 kg * 6.673E-11 m^3/kg/s^2 * 3E8 m/s)
ArealDensity = 7.67E-4 kg/m^2
So all we need to do is make a very thin structural membrane, line it with incredibly efficient solar cells, as well as efficient transmission to the laser stations studded every few tens of thousands of square kilometers, into a sheet of membrane that masses around 7 grams a square meter! (safety factor, as well as extra to hold up those laser installations) Easy peasy, that's just an order of magnitude less than a sheet of ordinary paper! For an even more relevant example this paper references a current deployed solar array areal density of 80 g per square meter. Coincedentally enough that's actually exactly the areal density of a sheet of paper, so an order of magnitude of improvement is actually what we are trying to achieve.
As far as the total mass of this system, that's ArealDensity * 4 * pi * radius^2. Let's think really grand and build it 10% past Saturn. .0007 * 4 * pi * (1.1 * 1.43E9)^2 = 2.18E16 kg. That's only 3.6E-9 the mass of our planet, or 2.3E-5 the mass of Ceres, so once we get Asteroid mining started up that'll be no problem. Heck, if you wanted to be lame and build it at 1.1 times Earth's maximum distance from the sun you could make it more than 100 times lighter than the Saturn variant.
There are only 2 ways to win an argument:
You bring your opponent over to your point of view and they agree with your superior logic and evidence.
You are brought over to your opponents position and agree with their superior logic and evidence.
Unless I am mistaken, you haven't listed two way to win an argument; you've listed one way to win and one way to lose. These don't even exhaust the ways there are to end an argument.
There actually are two ways to win an argument, namely (1)You bring your opponent over to your point of view and they agree with your superior logic and evidence. (2) You bring your opponent over to your point of view through some logically irrelevant means.
The number of irrelevant means are endless: wear him down, make him feel stupid, encourage him to jump on the bandwagon ... the list goes on.
GP is correct, those are the only two ways to win the argument. You do list several ways to end an argument, but, for example, neither of you "wins" if you simply wear him down such that he doesn't agree with you but just wants you to shut up.
If during the course of the argument you decide that your "opponent" was right then you have both won. You now have more knowledge and/or wisdom than you had before, which is the closest thing to a win such a discussion can ever have. Your "opponent" wins as well, as his position has been vindicated, and he may have learned something or gotten more food for thought along the way.
It is terrible to view the "opponent" being correct as a loss. Humans hate to lose, if someone feels like their "opponent" being right will lead to them losing then the solution is simple: buckle down and find a way to convince yourself the other party is wrong. There are many ways to lose an argument, but being wrong and not realizing it at the end is close to the worst. The worst is being wrong and convincing the other party that you are right. A naive or overly competitive person will view this as winning, in truth that is a terrible loss for each of you.
That would be an interesting next step to take. When I took my first CS class I put my own spin on the Game of Life, it was still an orthogonal board, but with two species, Cows and Wolves, with different propagation rules. You could make some interesting gliders with them, the Wolves appeared to chase the Cows.
According to the human players, poker is largely about mind games.
Really? The pros I have heard have spoken about probabilities, trying to determine your opponents' strategies (are they betting conservatively? do they bet on weaker hands more frequently than expected?), and measuring expected returns quickly. Tells and psychology seem to be a small part of their strategy, and unsurprisingly, professional poker players defeat the AI players despite the fact that computers have no psychology to play against.
"Trying to determine your opponents' strategies" is a portion of that mind game. The fact that professional human beings continually smoke current AIs is an strong indicator that psychological ploys are at work. If the game was all about probabilities then the computers would destroy human beings every time. As you say, the computers have no psychology to play against, they are generally predictable, and do not have the algorithms to judge character, intent, motivation (aka the psychological mind games) that would let them in turn predict the human's actions.
The sort of strategy you mentioned, determining whether a player is more likely to bluff with a weak hand, is exactly the sort of thing that will get an AI to lose their money once the human changes their strategy partially through the game, whether for a big hand, or over time just to throw off the other players.
Goddamnit, I just used my last mod point and here you are sitting at 2.
Al Awlaki was killed in Yemen, after the Yemeni government ordered him captured dead or alive, right? You need a better example than this for bashing the US. http://en.wikipedia.org/wiki/Anwar_al-Awlaki
Ah ok, so once you are convicted in Yemen the US military can be used to carry out the sentencing? Interesting, I didn't realize that this country worked for Yemen. Honestly though, I'm relieved. I used to think that the US was responsible for all of their actions around the world, and it made me pretty ashamed. Now I can just say "Sorry guys, we know this looks bad, but our hands are tied, Yemen told us to do this."
Whoo-hoo-hoo, look who knows so much. It just so happens that your friend here is only mostly dead. There's a big difference between mostly dead and all dead. "Mostly dead", is "slightly alive". With "all dead", well, with all dead, there's usually only one thing you can do.
Who wants to bet that the top of the list of "flagged" sites will be comprised of EU government and law enforcement sites? I guess we'll only know for sure if they refuse to release a list of the top sites flagged. In fact, I dare say that the list will be so cluttered with joke flaggings that it will be difficult to determine what, if any, sites identified are actually "inciting terrorism" (not helped by the fact that one man's terrorist is another man's political leader).
You are incorrect in thinking that those are false positives. Every single flag is guaranteed to find a terrorist, the site being flagged, or the person doing the flagging. Obviously if you are going to sabotage their intelligence gathering with protests against Big Brother you must be one of Them.
A few boats might take damage or even be sunk, but I'd hardly think that the whole fleet would be in collectively in jeopardy.
The concern isn't that the entire fleet would be destroyed. As you have conceded, a few of our ships "might take damage or even be sunk". That's a pretty tremendous victory for Iran if that happens. Best case scenario they get a Ticonderoga class Cruiser, which costs about a billion dollars (although we haven't been building them for 27 years, so I'm not sure how we'd actually replace it). We may lose an Arleigh Burke instead, which Wikipedia places at $1.8 billion. If Iran can accomplish that with a couple million dollars in boats and rockets than that's an amazing upset.
Carriers seem like an awfully good projection of power for an immediate (less than 12 hours) retaliation, but round trip from the USA to Iraq and back is only 30-50 hours these days (by bomber).
I think it's an open question whether or not that sort of tactic is effective by itself, especially against a larger opponent. Keep in mind that there are only 19 B-2s ready for combat (the other active B-2 is used for testing purposes) and they average 119 man hours of maintenance per hour of flight, so each B-2 will only be flying once every 5-6 days tops. That's just not a lot of bombs dropping, especially if you are fighting over multiple fronts so that all of your centrally located aircraft now have a much larger area to cover.
That said the B-2 isn't the only long-range bomber like that, you also have the B-1 and the B-52, so once you add those in you may indeed be overshadowing what your aircraft carriers are able to field, especially because each of those planes can be fielded from alternative positions like Germany, giving a much smaller roundtrip.
I still think that you can't beat carriers for their addition of many, many smaller yet capable planes that are able to respond much quicker, loiter better because they are based closer, etc.
I'd guess the plane-carried ABM lasers could fry a satellite in actual Star Wars style as well, if that program happened to be funded by whatever administration was in charge during the war - that's some really impressive technology.
The technology necessary to fry a satellite is much less impressive, and much older, than the sort of lasers we are finally seeing today. The plane-carried ABM lasers needed to be portable (obviously) because they needed to be carried where they could target the launch sites, where the ICBM is still slow and has lots of propellant to catch on fire. In order to get a high-powered laser in a package a (very large) plane would carry they use chemical based lasers that produce very high power pulses but have a limited number of shots.
Frying a GPS satellite is a lot easier, you do it from a ground station, so you have access to way more power and larger machinery (if you wanted to take out a satellite over China, and not over you then you'd need to put this on a ship or something), and you don't need a high-powered laser. We aren't vaporizing anything, we're just gently warming it. When people think lasers they are thinking something like this recent video, where a laser melts through a car hood and (supposedly) the engine underneath. That's totally overkill for what you need though, the boiling temperature of aluminum is 2467 degrees Celsius, heating a satellite to a hundred degrees Celsius would be more than enough, and while that takes more energy than the above video shows (larger mass being heated) it takes way less power, because you don't need to do it in two seconds, three hours is fine.
You actually don't need a laser at all, really any spectrum of light you throw out there will do. An old (in both senses of the word) coworker of mine told me that one of the Apollo missions was landing near an existing instrument on the moon that transmitted on the same frequency of one of the Apollo commands. They didn't have the ability to remotely turn off the device so they just pointed a very powerful antenna at it and broadcast noise until they were sure it was dead. No citation for that unfortunately, but I would love one if someone else knows of this.
Not really a concern - the US can certainly shoot down all the satellites it wants to. Those in lower orbits like GPS and spy sats can be taken down by (relatively) cheap missiles launched from a jet at high altitude. They'd all be gone in the first few hours of a real war.
Our GPS Satellites are in Lower Earth Orbits. These BeiDou satellites are in Geosynchronous orbits, far outside of our missile range, and possibly for exactly this reason. Keep in mind that in that "real war" the process of destroying the few dozens of enemy satellites you want to destroy will produce enormous debris clouds through LEO, possibly destroying yet more satellites and causing yet more debris clouds. This sort of has a MAD effect, as such a shooting war could wipe out most of the planet's LEO real estate. However, if one party doesn't have hardly any assets in LEO, this stops being much of a concern for them, it's sort of like if the US or Russia had developed an impervious ICBM shield at the height of the cold war.
Unfortunately for the US, not only is China starting out their space infrastructure in higher orbits, but the Russians have done this for decades as well. Ever since the Space Shuttle came around with the capability of grabbing LEO satellites and bringing them back down for analysis the Russians started putting their Top Secret military satellites up in higher orbits where the Space Shuttle couldn't get them. Now they aren't as vulnerable to a Space Debris Doomsday scenario either.
However, just because we can't hit GEO sats with missiles doesn't mean we can't destroy them. Satellites are very thermally sensitive due to how difficult it is to dump heat in space, and by definition GEO sats don't move with respect to the Earth much, so it's theoretically pretty easy to destroy them with lasers. And I don't mean vaporizing them with Star Wars lasers, I mean shining a high power laser on them for several minutes or hours and slowly adding more heat to the satellite than it can dump. Hard to do this to a LEO, (from a single ground station) you'll only get a shot at it for five or six minutes at a time, and it'll have its entire 90 minute orbit to cool off again, but you can shoot at a GEO forever.
I thought it would be about a constitutional right to keep and bear DDOS systems and pen test tools.
Yeah, I too was expecting a discussion of the sorts of encryption, malware, etc that should be understood to be defined as "arms" in the modern world, and which of them should be considered to fall under the second amendment.
The telescope is "seeing" the planet as it was 946 years ago ... maybe it's not even there any longer
I know, planets these days are always picking up and vanishing without even saying good bye. First Ceres, then Pluto. Every morning I wake up I breathe a sigh of relief that the Earth is still here.
But by that logic, leading a sedentary lifestyle will lead to long life. Everyone is different and some people put on muscle mass way faster than others, just from their natural genetics. Being able to put muscle on easier than average is far from a sure ticket to a heart attack.
So you are saying that either hulked out mutated muscles are the healthiest way to live, or a sedentary person that never moves a muscle is the healthiest way to live?
No room in your hypothesis for a middle ground that doesn't go all the way to one enormous extreme being the best?
Both applications were from The Mote in God's Eye.
No, I think that kind of overly complicated system makes him eminently qualified for a position in a government bureaucracy.
I know, who can divide by two anymore.
So why is NASA spending $2.5B on the next Mars Rover and planning to spend over $6B more on a Mars sample return when it can't find the money for much cheaper missions to Europa or Enceladus?"
This summary doesn't accurately describe the situation at all. The Mars missions are so more expensive largely because they are doing more. The next Mars Rover is going to be larger, heavier, and more capable than the two previous--wildly successful--rovers in pretty much every way. That $6B mission is a sample return mission, lifting off and bringing a research payload from Mars back to Earth is an enormous technical challenge. It's never been done before and that will drive most of the cost.
Also the linked missions aren't quite as cheap as the summary implies. The proposed mission to Europa has an estimated cost of $2.5 billion (and $4.7 billion is the given estimate in the last paragraph of the first link in the summary), exactly the same price as the first "overly expensive" Mars mission mentioned. The Enceladus trip is much cheaper, estimated at a little over half of a billion, so that at least is a reasonable alternative, though I still want to point out that that mission is much earlier in the planning stages, and missions that diverge a lot from previous missions are more likely to have ballooning costs as new found kinks are worked out.
Another issue is that not only are the Mars missions promising more, but there is a much greater chance that they will be able to live up to those promises. Every single Mars mission we've done so far has added to our body of knowledge on the planet, and our ability to better plan a mission and engineer a craft that can get more and better data on the next run. From Viking and on we have answered many, many questions about Mars, and learned about even more questions (meaning that we know the sort of doodad that needs to be on the next mission to answer that new question). Starting a new series of missions to a new celestial body means that in a lot of ways you have to start back at the drawing board again. This is another reason to start small on a new body, better to have 3-4 partially successful $200 million missions leading up to that big $2.5 billion dollar rover mission rather than trying plan a $2.5 billion mission right of the bat.
I should clarify that I don't think that investigating these moons is a bad idea. I think it's a wonderful one. However I don't think that we should investigate these moons in place of Mars, when we have already accumulated so much experience on how to investigate Mars. It's also worthwhile to note that this was the viewpoint of every scientist interviewed in the article. Nobody said that they didn't want to go to Mars, they all said that they wanted this moons visited in addition to Mars, not instead of.
Unless those photons come from a moon-sized space station.