It's not going to have anything to salvage once it hits the water anyway... The entire design is built to survive mach 7 enthalpies (5000 deg R) for about 30 seconds. The cooling mechanism involves passing liquid hydrogen beneath the skin of the craft, heating it to about 4000 degrees, then pumping it to the engines to burn. Once the fuel runs out, the unprotected airframe will do 2 things: 1) turn to slag from the incredibly high stagnation temperatures, 2) tear to pieces from the sudden deceleration.
Remember, Tt and D are f(M^2)... when M gets large, both become dangerous.
turn radius r=(v^2)/g(sqrt(n^2-1)) where g = 32.2 and n = load factor.
At mach 10, a vehicle pulling 3 g's would have a turn radius of ~260 miles. That means that a plane flying due west over Atlanta would enter a 3g turn, pass over Little Rock, AK, St Louis MO, and Cincinatti OH before it pointed east. (It would take 4 minutes and 12 seconds to perform the maneuver). At 2 g's it would overfly Topeka KS, Des Moines, and Milwuakee... and would take 7m 14s.
of course all analogies are bad, but a better analogy would be that you and NASA decide to build a house. NASA pays to buy the plot, design and build the house in compliance with all the local building codes and regulations, and then lets you put your name on the title (for free). All you have to do is provide a refrigerator and do designated driver duties on weekends.
Well, you kind of lied about having a fridge and a car, so you spend about two years getting them together for the apartment. In the interim, forced to rent a car and eat out every night because of the lack of furnishings, NASA has to struggle to keep the bank from foreclosing.
Once you finally get your $hit together and move in, you decide to throw a party (against the wishes of your good friend NASA) and invite your buddies over. Since you're already drunk and they don't have cars, you tell NASA to pick them up for you. They bring their own beer, fortunately, but when the party is over they leave it in the fridge and you don't let NASA drink any of it. It's your fridge, after all.
After the party there is puke everywhere and cigarette burns on NASA's nice new couch. You apologize sincerely, but still don't share the beer.
OK, here's the quick and dirty on the relationship between bouyancy effects and inertial effects created by a fan.
Bouyancy effects in low speed flows are measured by engineers using a nondimensional number called the Grashof #. It is defined as
Gr = g*Beta*rho^2*L^3*(Tw-To)/Mu^2
Where g = 32.174, Beta is the coefficient of thermal expansion, rho is air density, L is reference length (in this case the distance between hottest spot, directly over processor, and exhaust port), To is temp at exhaust, Tw is processor temp, and Mu is the viscosity of the air (assumed constant here although mu is temp dependant.)
Since there is no velocity term here to account for the role of the fan, we have to introduce the Reynolds # Rho*V*L/Mu. V is the average between the velocity of the air leaving the fan and the velocity of the air at the exhaust.
Essentially, Gr/Re^2 becomes a new non-dimensional # called the Froude # for forced motion: Beta*g*L*(Tw-To)/V^2
For Gr/Re^2 < 1, the bouyant effects are less important than the fan effects. The reverse is true for Gr/Re^2 > 1 .
In a typical computer case, L = ~24 inches, Beta = 1/To = 0.002 (perfect gas below 500 R), Tw = 650, To = 518, and V = 12 in/s. Thus Gr/Re^2 = 2.82, >> unity -> bouyant effects are more important than fan effects on a global scale. However, on a local scale L= 4 inches or so, (in the vicinity of the processor), Tw= 650, To = 518 and V = 24 in/s, Gr/Re^2 = 0.015 << 1 -> fan is necessary to keep cool locally.
The problem is that To rises to much higher than normal temperatures when the case isn't properly ventilated. So if you have a case with nowhere for the air to go, you may have problems. Heavy duty fans like those used by you crazy overclocker types help to solve this by moving air away from the processor, but a better engineering solution would be to simply increase ventilation.
Taking the walls off your case almost always increases ventilation more than putting a big fan in; I've got a 750 tbird at 848 in a relatively small case with 4 (hot) 7200 rpm seagate 19171wc's and a voodoo3, and it overheats with the cover on in a matter of a few minutes. With the case top off (the walls don't really matter) it runs for days.
i bought some double sided cdr's from a dude on Ebay... they were bright orange on one side and silver on the other. They weren't advertised as such, but they burned just fine on either side. I tend to still use only one side of them though, since if you burn on both sides you have no clue what's on them when they sit on your desk unlabeled.
Well, it depends on your tire design I suppose. If you compartmentalized the tire well enough and used some kind of emergency reinflation system like that "great stuff" expanding foam to refill the punctured compartments...
Student informing, encouraged and epidemic in American schools since well before the Columbine killings, is an irrational, anti-democratic practice that SNIP
I guess it would be better (err, more democratic?) if students got together and voted to suspend each other, instead of reporting kids who appear to have severe problems? If someone threatens to kill somebody, I'm sure as hell going to at least report him to someone in a position of authority. If you don't like it, don't make empty threats in public.
Now, I agree that the authorities got carried away in this case, and I think the kid is perfectly within his rights to sue over it. But I don't agree that reporting potential killers in any way threatens my constitutional rights.
I'm thinking that a properly oriented high power snowblower-like device, mounted in front of your tires, could probably do pretty good job against at least small-time Tackers. Those who put more time and effort into their work (by sticking nails into 1x8 boards or pounding their tacks into the soft pavement) would be harder to fight- but it could be done. Self sealing tires would be the obvious easiest solution, although you could have lots of fun combining directed energy/acoustic weapons, liquid nitrogen, and road analyzing radar.
Well, ideally I wouldn't have to pay for their health care. At the very least, they have higher insurance premiums, and at worst they wouldn't qualify for coverage under the same plans as I do.
The main difference, however, is that I have to pay taxes, whereas I can go without health care insurance without being beaten up by government thugs.
Speaking of irix... Check this out. Very pretty irix-like desktop for linux on intel.
BTW Irix does most of it's pretty stuff in prom, which unfortunately makes it almost completely un-customizable. Gets old fast if you reboot a lot (as in, a dozen times a night to test I2 scsi adapters).
The war on drugs qua drugs and drug users qua drug users is ridiculous. People should be able to do anything that doesn't hurt others- which means that we should definitely have a war on drug addicts who murder, rape, rob, etc., but only on those people, not on harmless druggies. Money laundering is a crime which hurts me by masking crime or by forcing me to pay higher taxes, therefore it should be enforced as well.
Spamming hurts me in less tangible ways- they eat my time and my bandwidth. I think that spammers should be fined, not jailed, at a rate proportional to the amount the person reading the emails would have earned in the amount of time he spent reading the email (say one second per word, with a minimum fine on the order of $.50). People could rate their email addresses at whatever amount the wished to, and the spammers could decide what price they were willing to pay to broadcast their spam. People who didn't pay the fines should go to jail.
That would bring unsolicited email barriers to entry up to the level of USPS mail, and help to solve the problems (as well as make me some money, fast.)
I always assumed that it had to do with stages of guild navigators (as, in the original movie: "Emperor, the 3rd stage guild navigator is here to see you now") where the 3rd stage is almost completely metamophosed.
The thopters were the most annoying thing to me... an ornithopter is a craft who propels itself by flapping its wings like a bird. The only thing even approximating ornithopters in the tv series so far has been the Harkonnen aircraft (who weren't even supposed to be a strong force in the air) but they didn't flap their wings. And why the hell did the harkonnen aircraft use targeting computers? They completely forgot the whole butlerian jihad.
Stealing money from people, lying to them, fraudulently assuming unearned credentials and breaking the very promises upon which the entire world economy is founded is morally wrong, bad, and not very funny. It may be entertaining- especially if the guy gets caught and spends the rest of his life giving blowjobs in prison- but it isn't especially something I'd like to learn from either.
Some things that are illegal are not morally wrong, bad etc., but no one glorifies tax evasion or u-turns on deserted roads at 3 am. The guys who get glorified are the killers, the rapists, and the violent thieves. And don't fool yourself with some kind of pseudo-philosophical babble; we do it because its sexy, and because it sells movies. It's entertaining, and Sylvester Stallone gets to take his shirt off while chasing the bad guys, and that excites people.
I don't think this guy would have been a "hacker" or a "cracker" or any of that if he was doing his thing today. I think he'd be a spammer, with some kind of innovative "make money fast" scam or some late night "no money down" real estate scheme. But then again, I'm a cynic.
I disagree. The corporations want to make money- and they'll do that by selling us Wagner or by selling us Spice Girls (a better example than Winger, although i agree that Winger sucked pretty badly).
Rock is more popular than classical for several reasons:
a) it's easier to make, therefore more people will make it. Less skill level involved ->less barriers to entry -> more profit potential -> more human participation. We are capitalist beasts, creatures of economics, whether we like it or not
b) attention spans no longer support 45 minute songs. even within a single genre-lets pick rock- look at the success of 3-minute-song-bands like green day vs. the success of musically superior 12 minute-song-bands like Dream Theater or Fates Warning. Attention span is a function of culture
c) many more people identify with dave mustaine than with luciano pavarotti. Mustaine wears blue jeans and a leather jacket- pavarotti wears a $3000 suit. Mustaine smokes cigarettes- LP smokes havana cigars. It costs $100 for good seats at a symphony, and you have to dress up- how many women even own opera dresses these days?
d) rock is advertised better than classical. This is the one sphere of influence the corporations do have- just go to Best Buy and check out the classical cd selection vs. the R&B selection. The classical cd's will be sheathed in boring, pastel cases with pictures of Vienna imposed over a wooden violin (or vice-versa, for the more risque pieces). The R&B cd's will have muscular young men and lithe females dressed to fuck.
which brings me to (e): sex. Like it or not, modern popular music is much sexier than the classical stuff (does anyone actually buy ricky martin for his singing voice? How about jennifer lopez?) Yo-yo ma just can't compete.
What does it say about human nature, or at least about our current civilization, when cheating at video games (especially single player video games) becomes the single point of commonality for a generation of people? Even if it isn't completely true and JonKatz is exaggerating, the fact that he chose that concept out of all the possible hooks means that it exists.
Or, I guess, it could mean that Katz really sucks at video games
Your comment is insightful as hell- but I think you're drawing the wrong conclusion from it. Television turned us into spectators, while video games (and the internet, eventually) are going to reverse that trend and make us the most participatory culture in history. Instead of watching fat football players knock each other around or watching Clint Eastwood charge up a hill, we have the ability to actually become these people, experiencing the excitement of a virtual life that far exceeds the tedium of our daily lives. Slashdot and sites like it are going to become ubiquitous- because eventually people are going to become dissatisfied with having the news read at them. We'll want to respond, interact, participate with it.
I'm reminded of stephenson's Diamond Age-style participatory entertainment here- soon we'll have gaming technology that rivals it and probably surpasses his vision in many ways. It will change the way we live and think, play and interact, regardless of what our "moral leaders" do to prevent it. And like every major shift in lifestyles that has ever occurred, whether this is a good trend or a bad trend is unforeseeable to us, although it will seem obvious to our grandchildren; playing video games, taking them as seriously as, say, I took high school football and wrestling, requires a willful suspension of reality. And that could be as dangerous to a person or a society as any tribe of barbarians- but it could also allow us to accomplish things that no one today can even dream of.
Chair Force- how clever... and unfortunately not far from the truth, at least for a lot of the techie types like myself, stuck in cubicles.
Then again, my old roommate flying F-16's now in South Korea might tend to disagree. Those folks keep in pretty good shape, because if you don't you get dropped from flying status (or you black out and become fertilizer).
We also sent our share of masochists to play army and, although everyone I know who went was above average physically, none did poorly there. I didn't go myself, electing to spend my one free summer jumping out of airplanes instead; I've always kind of regretted it.
Reading your article, I couldn't for the life of me figure out what you were protesting against. Care to enlighten me? It was a pretty well written piece, but if all you did was block traffic for no reason then you should have gone to jail. The same as any other group of people who seriously inconvenience a large group of other people, with malicious premedition, without just cause. Even if it was a lot of fun, really exciting, whatever. And regardless of whether you impressed any nappy chicks.
Don't get me wrong, civil disobedience is an important and useful tool (and I've participated in more than one "event" myself), but only if used properly. If no one knows why you are doing it then all they see is that they can't get to work, or that the windows of their favorite chinese restaurant are broken. When misapplied it becomes self-defeating and generally wasteful- especially in a democracy.
FYI the site is broken, the link to pages 4-9 or so (all but the first 3 and the last one) have to be manually adjusted in the url bar. For example if the "continue" link points to http://www.hackedtobits.com/100300/090300/dissent7 .htm, the actual url of the story is http://www.hackedtobits.com/100300/dissent7.htm
If I was you I would be interested. Because whoever wins the United States presidential election will have unlimited access to the worlds largest stockpile of nuclear weapons, as well as the most powerful conventional military forces the world has ever seen. He will also be in a position to make trivial daily decisions which influence the economy of the entire world.
Whatever misguided hubris you may feel regarding your own states importance is irrelevant; the most powerful, prosperous and influential country in the world is about to change its leadership, and that is a pretty newsworthy event.
Density is generally a function of air temperature. (pressure = density times temperature times a gas constant).
what dasunt said was correct, but incomplete. The speed of sound is, by definition, the speed at which pressure waves expand isentropically from a disturbance source. They will expand faster in a denser medium, but only because in similar, physically unconstrained gaseous mediums, density is a function of temp.
You have to be careful about the way you think about this because two gases with identical densities but different temperatures will have different speeds of sound. At similar temperatures but different densities, they will have identical speeds of sound.
When you move from gases to solid mediums, other physical phenomena come into play.
Mach number is defined as the ratio between velocity and the speed of sound. All you need to know to find speed of sound is the static temperature of the air.
Airspeed is measured by comparing the dynamic pressure of the air to the static pressure of the air, using the isentropic relations. Of course you'll have to correct for the normal shock pressure lossses when you start getting into the supersonic flight regime.
Slashdot Mirror
It's not going to have anything to salvage once it hits the water anyway... The entire design is built to survive mach 7 enthalpies (5000 deg R) for about 30 seconds. The cooling mechanism involves passing liquid hydrogen beneath the skin of the craft, heating it to about 4000 degrees, then pumping it to the engines to burn. Once the fuel runs out, the unprotected airframe will do 2 things: 1) turn to slag from the incredibly high stagnation temperatures, 2) tear to pieces from the sudden deceleration.
Remember, Tt and D are f(M^2)... when M gets large, both become dangerous.
turn radius r=(v^2)/g(sqrt(n^2-1)) where g = 32.2 and n = load factor.
At mach 10, a vehicle pulling 3 g's would have a turn radius of ~260 miles. That means that a plane flying due west over Atlanta would enter a 3g turn, pass over Little Rock, AK, St Louis MO, and Cincinatti OH before it pointed east. (It would take 4 minutes and 12 seconds to perform the maneuver). At 2 g's it would overfly Topeka KS, Des Moines, and Milwuakee... and would take 7m 14s.
That's at sea level (a=1116 ft/s).
Neh
aero geek
Another niven-pournelle ripoff (read footfall)
neh
of course all analogies are bad, but a better analogy would be that you and NASA decide to build a house. NASA pays to buy the plot, design and build the house in compliance with all the local building codes and regulations, and then lets you put your name on the title (for free). All you have to do is provide a refrigerator and do designated driver duties on weekends.
Well, you kind of lied about having a fridge and a car, so you spend about two years getting them together for the apartment. In the interim, forced to rent a car and eat out every night because of the lack of furnishings, NASA has to struggle to keep the bank from foreclosing.
Once you finally get your $hit together and move in, you decide to throw a party (against the wishes of your good friend NASA) and invite your buddies over. Since you're already drunk and they don't have cars, you tell NASA to pick them up for you. They bring their own beer, fortunately, but when the party is over they leave it in the fridge and you don't let NASA drink any of it. It's your fridge, after all.
After the party there is puke everywhere and cigarette burns on NASA's nice new couch. You apologize sincerely, but still don't share the beer.
Neh
OK, here's the quick and dirty on the relationship between bouyancy effects and inertial effects created by a fan.
Bouyancy effects in low speed flows are measured by engineers using a nondimensional number called the Grashof #. It is defined as
Gr = g*Beta*rho^2*L^3*(Tw-To)/Mu^2
Where g = 32.174, Beta is the coefficient of thermal expansion, rho is air density, L is reference length (in this case the distance between hottest spot, directly over processor, and exhaust port), To is temp at exhaust, Tw is processor temp, and Mu is the viscosity of the air (assumed constant here although mu is temp dependant.)
Since there is no velocity term here to account for the role of the fan, we have to introduce the Reynolds # Rho*V*L/Mu. V is the average between the velocity of the air leaving the fan and the velocity of the air at the exhaust.
Essentially, Gr/Re^2 becomes a new non-dimensional # called the Froude # for forced motion: Beta*g*L*(Tw-To)/V^2
For Gr/Re^2 < 1, the bouyant effects are less important than the fan effects. The reverse is true for Gr/Re^2 > 1 .
In a typical computer case, L = ~24 inches, Beta = 1/To = 0.002 (perfect gas below 500 R), Tw = 650, To = 518, and V = 12 in/s. Thus Gr/Re^2 = 2.82, >> unity -> bouyant effects are more important than fan effects on a global scale. However, on a local scale L= 4 inches or so, (in the vicinity of the processor), Tw= 650, To = 518 and V = 24 in/s, Gr/Re^2 = 0.015 << 1 -> fan is necessary to keep cool locally.
The problem is that To rises to much higher than normal temperatures when the case isn't properly ventilated. So if you have a case with nowhere for the air to go, you may have problems. Heavy duty fans like those used by you crazy overclocker types help to solve this by moving air away from the processor, but a better engineering solution would be to simply increase ventilation.
Taking the walls off your case almost always increases ventilation more than putting a big fan in; I've got a 750 tbird at 848 in a relatively small case with 4 (hot) 7200 rpm seagate 19171wc's and a voodoo3, and it overheats with the cover on in a matter of a few minutes. With the case top off (the walls don't really matter) it runs for days.
Hope this helps,
Rev. Neh
Resident aero type
i bought some double sided cdr's from a dude on Ebay... they were bright orange on one side and silver on the other. They weren't advertised as such, but they burned just fine on either side. I tend to still use only one side of them though, since if you burn on both sides you have no clue what's on them when they sit on your desk unlabeled.
Well, it depends on your tire design I suppose. If you compartmentalized the tire well enough and used some kind of emergency reinflation system like that "great stuff" expanding foam to refill the punctured compartments...
Student informing, encouraged and epidemic in American schools since well before the Columbine killings, is an irrational, anti-democratic practice that SNIP
I guess it would be better (err, more democratic?) if students got together and voted to suspend each other, instead of reporting kids who appear to have severe problems? If someone threatens to kill somebody, I'm sure as hell going to at least report him to someone in a position of authority. If you don't like it, don't make empty threats in public.
Now, I agree that the authorities got carried away in this case, and I think the kid is perfectly within his rights to sue over it. But I don't agree that reporting potential killers in any way threatens my constitutional rights.
I'm thinking that a properly oriented high power snowblower-like device, mounted in front of your tires, could probably do pretty good job against at least small-time Tackers. Those who put more time and effort into their work (by sticking nails into 1x8 boards or pounding their tacks into the soft pavement) would be harder to fight- but it could be done. Self sealing tires would be the obvious easiest solution, although you could have lots of fun combining directed energy/acoustic weapons, liquid nitrogen, and road analyzing radar.
The roads must roll!
The best way to href a news article is to look it up in deja... Like this. though surely you knew that already...
Well, ideally I wouldn't have to pay for their health care. At the very least, they have higher insurance premiums, and at worst they wouldn't qualify for coverage under the same plans as I do.
The main difference, however, is that I have to pay taxes, whereas I can go without health care insurance without being beaten up by government thugs.
Neh
Speaking of irix... Check this out. Very pretty irix-like desktop for linux on intel.
BTW Irix does most of it's pretty stuff in prom, which unfortunately makes it almost completely un-customizable. Gets old fast if you reboot a lot (as in, a dozen times a night to test I2 scsi adapters).
Neh
The war on drugs qua drugs and drug users qua drug users is ridiculous. People should be able to do anything that doesn't hurt others- which means that we should definitely have a war on drug addicts who murder, rape, rob, etc., but only on those people, not on harmless druggies. Money laundering is a crime which hurts me by masking crime or by forcing me to pay higher taxes, therefore it should be enforced as well.
Spamming hurts me in less tangible ways- they eat my time and my bandwidth. I think that spammers should be fined, not jailed, at a rate proportional to the amount the person reading the emails would have earned in the amount of time he spent reading the email (say one second per word, with a minimum fine on the order of $.50). People could rate their email addresses at whatever amount the wished to, and the spammers could decide what price they were willing to pay to broadcast their spam. People who didn't pay the fines should go to jail.
That would bring unsolicited email barriers to entry up to the level of USPS mail, and help to solve the problems (as well as make me some money, fast.)
Neh
I always assumed that it had to do with stages of guild navigators (as, in the original movie: "Emperor, the 3rd stage guild navigator is here to see you now") where the 3rd stage is almost completely metamophosed.
Abstract conjecture; surely someone knows.
The thopters were the most annoying thing to me... an ornithopter is a craft who propels itself by flapping its wings like a bird. The only thing even approximating ornithopters in the tv series so far has been the Harkonnen aircraft (who weren't even supposed to be a strong force in the air) but they didn't flap their wings. And why the hell did the harkonnen aircraft use targeting computers? They completely forgot the whole butlerian jihad.
Stealing money from people, lying to them, fraudulently assuming unearned credentials and breaking the very promises upon which the entire world economy is founded is morally wrong, bad, and not very funny. It may be entertaining- especially if the guy gets caught and spends the rest of his life giving blowjobs in prison- but it isn't especially something I'd like to learn from either.
Some things that are illegal are not morally wrong, bad etc., but no one glorifies tax evasion or u-turns on deserted roads at 3 am. The guys who get glorified are the killers, the rapists, and the violent thieves. And don't fool yourself with some kind of pseudo-philosophical babble; we do it because its sexy, and because it sells movies. It's entertaining, and Sylvester Stallone gets to take his shirt off while chasing the bad guys, and that excites people.
I don't think this guy would have been a "hacker" or a "cracker" or any of that if he was doing his thing today. I think he'd be a spammer, with some kind of innovative "make money fast" scam or some late night "no money down" real estate scheme. But then again, I'm a cynic.
neh
I disagree. The corporations want to make money- and they'll do that by selling us Wagner or by selling us Spice Girls (a better example than Winger, although i agree that Winger sucked pretty badly).
Rock is more popular than classical for several reasons:
a) it's easier to make, therefore more people will make it. Less skill level involved ->less barriers to entry -> more profit potential -> more human participation. We are capitalist beasts, creatures of economics, whether we like it or not
b) attention spans no longer support 45 minute songs. even within a single genre-lets pick rock- look at the success of 3-minute-song-bands like green day vs. the success of musically superior 12 minute-song-bands like Dream Theater or Fates Warning. Attention span is a function of culture
c) many more people identify with dave mustaine than with luciano pavarotti. Mustaine wears blue jeans and a leather jacket- pavarotti wears a $3000 suit. Mustaine smokes cigarettes- LP smokes havana cigars. It costs $100 for good seats at a symphony, and you have to dress up- how many women even own opera dresses these days?
d) rock is advertised better than classical. This is the one sphere of influence the corporations do have- just go to Best Buy and check out the classical cd selection vs. the R&B selection. The classical cd's will be sheathed in boring, pastel cases with pictures of Vienna imposed over a wooden violin (or vice-versa, for the more risque pieces). The R&B cd's will have muscular young men and lithe females dressed to fuck.
which brings me to (e): sex. Like it or not, modern popular music is much sexier than the classical stuff (does anyone actually buy ricky martin for his singing voice? How about jennifer lopez?) Yo-yo ma just can't compete.
neh
What does it say about human nature, or at least about our current civilization, when cheating at video games (especially single player video games) becomes the single point of commonality for a generation of people? Even if it isn't completely true and JonKatz is exaggerating, the fact that he chose that concept out of all the possible hooks means that it exists.
Or, I guess, it could mean that Katz really sucks at video games
neh
Your comment is insightful as hell- but I think you're drawing the wrong conclusion from it. Television turned us into spectators, while video games (and the internet, eventually) are going to reverse that trend and make us the most participatory culture in history. Instead of watching fat football players knock each other around or watching Clint Eastwood charge up a hill, we have the ability to actually become these people, experiencing the excitement of a virtual life that far exceeds the tedium of our daily lives. Slashdot and sites like it are going to become ubiquitous- because eventually people are going to become dissatisfied with having the news read at them. We'll want to respond, interact, participate with it.
I'm reminded of stephenson's Diamond Age-style participatory entertainment here- soon we'll have gaming technology that rivals it and probably surpasses his vision in many ways. It will change the way we live and think, play and interact, regardless of what our "moral leaders" do to prevent it. And like every major shift in lifestyles that has ever occurred, whether this is a good trend or a bad trend is unforeseeable to us, although it will seem obvious to our grandchildren; playing video games, taking them as seriously as, say, I took high school football and wrestling, requires a willful suspension of reality. And that could be as dangerous to a person or a society as any tribe of barbarians- but it could also allow us to accomplish things that no one today can even dream of.
Neh
Chair Force- how clever... and unfortunately not far from the truth, at least for a lot of the techie types like myself, stuck in cubicles.
Then again, my old roommate flying F-16's now in South Korea might tend to disagree. Those folks keep in pretty good shape, because if you don't you get dropped from flying status (or you black out and become fertilizer).
We also sent our share of masochists to play army and, although everyone I know who went was above average physically, none did poorly there. I didn't go myself, electing to spend my one free summer jumping out of airplanes instead; I've always kind of regretted it.
Neh
Hi vergil,
7 .htm, the actual url of the story is http://www.hackedtobits.com/100300/dissent7.htm
Reading your article, I couldn't for the life of me figure out what you were protesting against. Care to enlighten me? It was a pretty well written piece, but if all you did was block traffic for no reason then you should have gone to jail. The same as any other group of people who seriously inconvenience a large group of other people, with malicious premedition, without just cause. Even if it was a lot of fun, really exciting, whatever. And regardless of whether you impressed any nappy chicks.
Don't get me wrong, civil disobedience is an important and useful tool (and I've participated in more than one "event" myself), but only if used properly. If no one knows why you are doing it then all they see is that they can't get to work, or that the windows of their favorite chinese restaurant are broken. When misapplied it becomes self-defeating and generally wasteful- especially in a democracy.
FYI the site is broken, the link to pages 4-9 or so (all but the first 3 and the last one) have to be manually adjusted in the url bar. For example if the "continue" link points to http://www.hackedtobits.com/100300/090300/dissent
Neh
If I was you I would be interested. Because whoever wins the United States presidential election will have unlimited access to the worlds largest stockpile of nuclear weapons, as well as the most powerful conventional military forces the world has ever seen. He will also be in a position to make trivial daily decisions which influence the economy of the entire world.
Whatever misguided hubris you may feel regarding your own states importance is irrelevant; the most powerful, prosperous and influential country in the world is about to change its leadership, and that is a pretty newsworthy event.
Density is generally a function of air temperature. (pressure = density times temperature times a gas constant).
what dasunt said was correct, but incomplete. The speed of sound is, by definition, the speed at which pressure waves expand isentropically from a disturbance source. They will expand faster in a denser medium, but only because in similar, physically unconstrained gaseous mediums, density is a function of temp.
You have to be careful about the way you think about this because two gases with identical densities but different temperatures will have different speeds of sound. At similar temperatures but different densities, they will have identical speeds of sound.
When you move from gases to solid mediums, other physical phenomena come into play.
Mach number is defined as the ratio between velocity and the speed of sound. All you need to know to find speed of sound is the static temperature of the air.
Airspeed is measured by comparing the dynamic pressure of the air to the static pressure of the air, using the isentropic relations. Of course you'll have to correct for the normal shock pressure lossses when you start getting into the supersonic flight regime.
Speed of sound is purely temperature dependent. Air pressure is incidental. At sea level the speed of sound is ~760 mph and at 100,000 ft it is ~675.