It's not totally broken, your problem about slow speeds when copying files over network drives is due to a "feature" of vista that compresses the files before transfer. Unless you have a ridiculously fast computer on a ridiculously slow connection, this is obviously a bad idea but for some reason Microsoft enabled it by default. Go look up how to disable "Remote Differential Compression".
I gather reverses the fan blades so that they blow forward rather than backward
Nope. For thrust reversers, the jet engine stays exactly the same, you just drop a bucket behind it. This redirects the exhaust air forwards, thereby braking the aircraft.
Here's a better reason: 1cm accuracy combined with guaranteed service quality will mean that the system is a lot more useful in many industries than GPS. I'm a pilot, so I'll use that example: while the grandparent's car's nav system isn't critical the instrument system used to perform zero-visibility landings on 800-passenger airliners is. DGPS with WAAS is already being used to perform non-precision instrument approaches, but the Selective Availability (currently disabled by the pentagon, but could be turned back on at any moment) and accuracy are what's holding it back from being adopted for Cat. IIIC instrument landings. A system with Galileo's proposed features would be way cheaper to install and operate than the ILS systems currently used, would be more accurate, and could even be used on the ground for taxiing in zero-zero conditions (a current major weakness for airliners).
If one uses one's imagination, one can also imagine 1cm Galileo signals taking car navigation systems to the point where they are completely autonomous for highway driving...
Considering that a 1-week stay on the ISS is $20 million, what would you rather have? A semi-useless sattelite that you can play with or a personal trip to outer space for just twice the price?
Ah but transformers are among the most efficient electrical components we know how to make - That wall wart is probably achieving between 3 and 7 nines of efficiency. Also, transforming already regulated AC is way more efficient than regulating DC.
I wholeheartedly agree. Unfortunately, there hasn't been anyone influential enough that has been pushing the concept since Bull's assasination. These days, science moves forward only when people who are passionate about a certain area pour their soul into it. The other thing is that as hard as rocketry is, we've had lots of experience with it and we have almost none with the kind of artillery that Bull wanted to build. Bull was a brilliant guy (he had earned his PhD @ 23 years old), and his guns were quite complex. We're talking multiple charges detonating along the length of several kilometers of the barrel, and he also used rocket sabots that would ignite at high altidude to give the projectile the last little boost.
For more information on the remarkable story of Bull and his supergun, check wikipedia:
That's because we're not just going to the moon. The CEV was begun with manned mars missions in mind, and lunar missions are only a stepping point. Everything about the CEV has to be stepped up a little bit because of that; thus the extra time.
1) bullet holes are no problem. Airships like the goodyear blimp get shot at regularly by rednecks and the compartmentalization keeps them afloat.
2) This thing should be able to carry a fairly advanced array of anti-missile weaponry and decoys. Combined with a low radar and heat signature, it's not as good a target as one might think. It should even have enough lifting capacity that they can throw in some anti-missile gatling guns like the ones they use on cruisers and aircraft carriers. Also, it flies quite high, out of the range of shoulder-launched missiles (they only have a range of a few miles), so you only really have to worry about conventional missiles.
3) Back in the heyday of airships, the US Navy actually built and tested "aircraft carrier" airships. They carried a complement of fighter airplanes on board, and could launch them at will for self defense. Recovery involved catching a cable hanging underneath the airship, not unlike arrestor cables on modern aircraft carriers. Updating the technology to the jet age and accomodating the higher speeds would not be easy, but it could be done.
In short, these things are a lot more practical for military purposes (let alone civilian) than one might think.
It says they "May be able to produce more engineers" and they "may be able to catch up while spending less money proportionally."
I don't know about spending less money proportionally, but China is already producing more engineers that the U.S. (I think I read in the economist article "the china syndrome" that they are graduating 2x the number of engineers per year at least, and that article is pretty old now).
Right. Have they been installing a lot of those superconducting powerlines in your area lately? How much does it cost to keep them cooled with LN2 (both financial and energy costs)?
there's a more reliable substitute for VOIP, there isn't for cell phones. The primary issues are still quality, reliability, and cost; and they're BIG issues either way.
T- stands for "Time minus". "Time" is when the main event occurs (the shuttle liftoff). All other times are specified as relative to this event. Thus, T minus 3 minutes is (theoretically) three minutes before the shuttle lifts off, and T plus 6 hours is 6 hours after the shuttle lifts off. The military uses this convention for operations too (e.g. D-Day plus 6 is 6 days after D-Day). This system is good because it allows things to be scheduled without knowing exactly when the main event is going to occur (the launch could be delayed by weather, etc).
The system isn't perfect though, which is why you have "holds" for some things. These "holds" allow time for activities whose duration is really difficult to predict.
This thread sounds like it has people who know what they're talking about, so here goes:
Given that mu is the ratio of "the forward speed of the craft to the speed of the tip of the rotor", I'm not sure how this is possible. When I see that statement, I take that to mean the maximum forward airspeed of the rotor tip is the same as the airspeed of the rotorcraft. If this is the case, isn't the blade standing still!? Think about this: when a blade-tip is perfectly perpendicular to the helicopter (longitudinal axis)and on the advancing side, if its airspeed is the same as the helicopter's, it shouldn't be moving relative to the helicopter...
Rotor blades not only change pitch and flap, but they also lead and lag freely. The angle between blades as viewed from above is not always equal. The main reason is that not only do you have stall speed problems on the retreating blade, but you've got shock wave problems on the advancing blade.
As a mech eng student, this is the only part I didn't really get. Are you seriously saying that the angle between blades changes in flight? (i.e. in a two-bladed helicopter the blades aren't neccesarily parallel in one line?) If so, is this just due to warping of the forward blade due to shock drag or does the swash plate coupling intrinsically allow for this? Do all helicopters have this? I work around helicopters quite a bit, (though not in an engineering capacity) and I'm very interested...
"Well, actually...the faster you go, the hotter the engine gets and the fuel efficiency goes up as more of the fuel gets burned instead of discharged."
This is true, up to a point. On most consumer vehicles, this point is in the 60-70kph region. Beyond that, the increased drag overshadows any efficiency gains. So, to be perfectly efficient, one should drive at the speed ideal for your car and never stop at red lights or stop signs.
Right, but even if the public doesn't condone going after North Korea, they might condone more funding or even powerful legislation that allows law enforcement more powers.
Well, that may be the case; but they do have big names on board, have a sizeable warehouse complex in seattle that is visited on a day-to-day basis by dozens of engineers, and they are dropping lots of money at it. They are super-secretive (they won't even let the water-cooler-changer guys in the building) which would explain the site too. If it a pipe dream, it's an expensive one...
Sure they do, look up a Class C ILS landing. Takes airliners all the way to wheels-on-the runway automatically on a regular basis these days.
If they're using retro-rockets like the DC-X that their ship is supposed to be based on, then ground control would be pretty useless as it may be impossible for a human to even fly the thing...
Um, actually as another posted pointed out - TW's physical assets are $45 billion, while Google's are worth $3 billion. So actually, those DVDs, projectors, recorders, archiving equipment, broadcasting equipment, and everything else that Time Warner has does add up.
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It's not totally broken, your problem about slow speeds when copying files over network drives is due to a "feature" of vista that compresses the files before transfer. Unless you have a ridiculously fast computer on a ridiculously slow connection, this is obviously a bad idea but for some reason Microsoft enabled it by default. Go look up how to disable "Remote Differential Compression".
Doesn't NASA still fly a -71 though for research purposes?
I gather reverses the fan blades so that they blow forward rather than backward
Nope. For thrust reversers, the jet engine stays exactly the same, you just drop a bucket behind it. This redirects the exhaust air forwards, thereby braking the aircraft.
Here's a better reason: 1cm accuracy combined with guaranteed service quality will mean that the system is a lot more useful in many industries than GPS. I'm a pilot, so I'll use that example: while the grandparent's car's nav system isn't critical the instrument system used to perform zero-visibility landings on 800-passenger airliners is. DGPS with WAAS is already being used to perform non-precision instrument approaches, but the Selective Availability (currently disabled by the pentagon, but could be turned back on at any moment) and accuracy are what's holding it back from being adopted for Cat. IIIC instrument landings. A system with Galileo's proposed features would be way cheaper to install and operate than the ILS systems currently used, would be more accurate, and could even be used on the ground for taxiing in zero-zero conditions (a current major weakness for airliners).
If one uses one's imagination, one can also imagine 1cm Galileo signals taking car navigation systems to the point where they are completely autonomous for highway driving...
So uh, why'd you leave?
Considering that a 1-week stay on the ISS is $20 million, what would you rather have? A semi-useless sattelite that you can play with or a personal trip to outer space for just twice the price?
Ah but transformers are among the most efficient electrical components we know how to make - That wall wart is probably achieving between 3 and 7 nines of efficiency. Also, transforming already regulated AC is way more efficient than regulating DC.
kudos - i haven't laughed that hard at /. in a while...
I wholeheartedly agree. Unfortunately, there hasn't been anyone influential enough that has been pushing the concept since Bull's assasination. These days, science moves forward only when people who are passionate about a certain area pour their soul into it. The other thing is that as hard as rocketry is, we've had lots of experience with it and we have almost none with the kind of artillery that Bull wanted to build. Bull was a brilliant guy (he had earned his PhD @ 23 years old), and his guns were quite complex. We're talking multiple charges detonating along the length of several kilometers of the barrel, and he also used rocket sabots that would ignite at high altidude to give the projectile the last little boost.
For more information on the remarkable story of Bull and his supergun, check wikipedia:
Gerald Bull: Biography
Project HARP: Bull's earlier work for the US gov't.
Project Babylon: Bull's work for saddam hussein that eventually got him killed by the Mossad
That's because we're not just going to the moon. The CEV was begun with manned mars missions in mind, and lunar missions are only a stepping point. Everything about the CEV has to be stepped up a little bit because of that; thus the extra time.
Answers to the "target problem"
1) bullet holes are no problem. Airships like the goodyear blimp get shot at regularly by rednecks and the compartmentalization keeps them afloat.
2) This thing should be able to carry a fairly advanced array of anti-missile weaponry and decoys. Combined with a low radar and heat signature, it's not as good a target as one might think. It should even have enough lifting capacity that they can throw in some anti-missile gatling guns like the ones they use on cruisers and aircraft carriers. Also, it flies quite high, out of the range of shoulder-launched missiles (they only have a range of a few miles), so you only really have to worry about conventional missiles.
3) Back in the heyday of airships, the US Navy actually built and tested "aircraft carrier" airships. They carried a complement of fighter airplanes on board, and could launch them at will for self defense. Recovery involved catching a cable hanging underneath the airship, not unlike arrestor cables on modern aircraft carriers. Updating the technology to the jet age and accomodating the higher speeds would not be easy, but it could be done.
In short, these things are a lot more practical for military purposes (let alone civilian) than one might think.
not to mention it's far enough away that the neighbours won't be filing noise complaints.
It says they "May be able to produce more engineers" and they "may be able to catch up while spending less money proportionally."
I don't know about spending less money proportionally, but China is already producing more engineers that the U.S. (I think I read in the economist article "the china syndrome" that they are graduating 2x the number of engineers per year at least, and that article is pretty old now).
wow. my comment was mostly sarcastic. wasn't even aware that this was possible today.
Right. Have they been installing a lot of those superconducting powerlines in your area lately? How much does it cost to keep them cooled with LN2 (both financial and energy costs)?
there's a more reliable substitute for VOIP, there isn't for cell phones. The primary issues are still quality, reliability, and cost; and they're BIG issues either way.
T- stands for "Time minus". "Time" is when the main event occurs (the shuttle liftoff). All other times are specified as relative to this event. Thus, T minus 3 minutes is (theoretically) three minutes before the shuttle lifts off, and T plus 6 hours is 6 hours after the shuttle lifts off. The military uses this convention for operations too (e.g. D-Day plus 6 is 6 days after D-Day). This system is good because it allows things to be scheduled without knowing exactly when the main event is going to occur (the launch could be delayed by weather, etc).
The system isn't perfect though, which is why you have "holds" for some things. These "holds" allow time for activities whose duration is really difficult to predict.
They are not referring to airspeed
Oh, ok. It seems a lot less impressive now though.
This thread sounds like it has people who know what they're talking about, so here goes:
Given that mu is the ratio of "the forward speed of the craft to the speed of the tip of the rotor", I'm not sure how this is possible. When I see that statement, I take that to mean the maximum forward airspeed of the rotor tip is the same as the airspeed of the rotorcraft. If this is the case, isn't the blade standing still!? Think about this: when a blade-tip is perfectly perpendicular to the helicopter (longitudinal axis)and on the advancing side, if its airspeed is the same as the helicopter's, it shouldn't be moving relative to the helicopter...
So can someone unravel my confusion?
Rotor blades not only change pitch and flap, but they also lead and lag freely. The angle between blades as viewed from above is not always equal. The main reason is that not only do you have stall speed problems on the retreating blade, but you've got shock wave problems on the advancing blade.
As a mech eng student, this is the only part I didn't really get. Are you seriously saying that the angle between blades changes in flight? (i.e. in a two-bladed helicopter the blades aren't neccesarily parallel in one line?) If so, is this just due to warping of the forward blade due to shock drag or does the swash plate coupling intrinsically allow for this? Do all helicopters have this? I work around helicopters quite a bit, (though not in an engineering capacity) and I'm very interested...
Thanks in advance.
"Well, actually...the faster you go, the hotter the engine gets and the fuel efficiency goes up as more of the fuel gets burned instead of discharged."
This is true, up to a point. On most consumer vehicles, this point is in the 60-70kph region. Beyond that, the increased drag overshadows any efficiency gains. So, to be perfectly efficient, one should drive at the speed ideal for your car and never stop at red lights or stop signs.
Right, but even if the public doesn't condone going after North Korea, they might condone more funding or even powerful legislation that allows law enforcement more powers.
Well, that may be the case; but they do have big names on board, have a sizeable warehouse complex in seattle that is visited on a day-to-day basis by dozens of engineers, and they are dropping lots of money at it. They are super-secretive (they won't even let the water-cooler-changer guys in the building) which would explain the site too. If it a pipe dream, it's an expensive one...
Sure they do, look up a Class C ILS landing. Takes airliners all the way to wheels-on-the runway automatically on a regular basis these days.
If they're using retro-rockets like the DC-X that their ship is supposed to be based on, then ground control would be pretty useless as it may be impossible for a human to even fly the thing...
Um, actually as another posted pointed out - TW's physical assets are $45 billion, while Google's are worth $3 billion. So actually, those DVDs, projectors, recorders, archiving equipment, broadcasting equipment, and everything else that Time Warner has does add up.