Imagine if Kennedy, in his 1961 State of the Union address, said he was going to invest billions in forming a massive group of scientists and engineers, and get them to do "I dunno, something cool." You think it would have resulted in a moon landing?
Imagine if an entrepreneur went to an investor asking for startup funding, with a beautiful Powerpoint showing innovative new organizational charts, an efficient supply chain, and a great advertising theme. "What are you going to make?" "I dunno, something cool."
If you want to make a great free-software game, come up with a great game idea first, and then gather some free-software resources to make it happen. Planning the administrative and legal issues before coming up with a product concept is the fast-track to mission failure.
This "poll" was done by show of hands in a large lecture hall. As a college professor, let me tell you: unless you're a very good teacher, the number of students in a college class who'll raise their hands when asked *any* question, up to and including "do you have a pulse?" is 2. Doesn't matter how big the class is: if it's a 2 person class, both will raise their hands. In a 500-person class, it's still 2, 'cause 300 of them aren't paying attention, and 198 are chicken.
If your deorbit burn is off by even a tiny fraction of a percent, you'll be splashing down in the south side of Chicago. And believe me, that's no place to park a billion-dollar spacecraft.
We're past the 24-hour "nobody cares" limit on Slashdot, but if anybody's still listening, mod parent up for bothering to do the math, even if he disagrees with me.
Another poster pointed out that your area math is wrong: the actual area comes to a patch of ground about 70 km on a side, proportionally more if you assume imperfect sunlight->electricity conversion. It's a sizeable patch of ground, but I'm sure we could find a few nice patches of desert or open ocean to park this on.
As for Hoover Dam: it only puts out 2 gigawatts because if it put out more, Lake Mead would run dry. So the clever designers only put in a few turbines. That's not a problem in this case, since we're refilling the lake every day. There's no problem in principle with installing *ten times* as many turbines and ten times as many generators. We drain the lake ten times as fast at night, and then fill it back up the next day.
Suppose we take the ten largest dams in the U.S. and assume they're all about like Hoover Dam. (In practice, we'd probably split the load among dozens of dams.) Each of these ten dams needs to supply 20 gigawatts of power at night.
Each dam needs to supply 20 gigawatts x 12 hours = about 9e14 joules of energy. Lake Mead holds 35 cubic kilometers of water, or 35e12 kilograms. The gravitational potential energy of the lake is about 35e12 kg * 9.8 * 200 m = 7e16 joules.
SO, if we install ten times as many generators in Hoover Dam, add a whole bunch of pumps, and repeat this setup at the ten largest dams in the country, we can handle the entire nighttime electrical load, and only drain 1% of the volume of each reservoir each day. Problem solved.
Added bonus: the Colorado River might run backwards from time to time, which means you can do an all-day whitewater rafting trip and end up back at your car!
Whoa, hang on a second. Five megabytes is the same storage as a nice two-volume set of hardcover books. Seek time of 600 milliseconds is only one order of magnitude less than the time it takes me to look up something in an index.
And the cost? Maybe a buck or two for the books, compared to 3200 per month in 1956.
So what advantage do these suckers have over a couple of big books, even in 1956?
If the "seek time" advantage is so crucial, use a RAID-0 system. Get ten girls from the typing pool to look through 10 books, giving you 10 answers at a time. It'll still cost less than $3200 per month.
At least 20 times in this discussion, someone's said "Give a man a fish, he has food for a day; teach a man to fish, he has food for a lifetime."
Nowhere in there does it say "give a man's kid a computer, and he'll have food for a lifetime." What the kid will have is a fancy gadget that he has no idea how to use, that does almost nothing to help his daily life, and that has zero connectivity or compatibility with the way the rest of the computerized world works (and I say that as a Mac user.) Someone here bragged about a special button on the keypad that enables source code editing of the current application. 99.9% of American kids would have no idea what to do with that, and they've got a titanic advantage in technical expertise from the get-go.
How about, y'know, teaching people to fish? Well, actually, they already know how to fish. Buy 'em a boat that works, so they can actually do some fishing. Get a bunch of 'em to work on building a good road to the capital city. Buy a dozen of them a delivery truck each, so they can deliver food in to town, and buy one the tools and training he needs to repair the trucks. For more developed areas, scale it up: help someone start a small manufacturing shop, a textile mill, a hydro power plant, a computer store. Provide capital equipment and infrastructure to help them take one technological step up at a time.
OLPC makes the same mistake that Dvorak does: they fail to see "progress" as the gradual development of an interconnected, self-maintaining infrastructure, in which each person helps to build, maintain, and develop stuff needed by someone else. The broader and deeper that network, the more successful the society. Dropping stuff out of the sky, whether it's high-tech computer or sacks of food, does nothing to develop that web.
"Base load" is a bad phrase to use for this issue (to the extent it's an issue). Today, the base load is the electrical demand that's always there, 24/7. It's met by sources like coal and oil and nuclear that can't be started or stopped slowly (or are just too expensive to allow to sit idle); we've got stuff like natural gas plants that we switch on quickly to meet the occasional peak in demand. In a renewable energy future, the problem is that occasionally, it's nighttime and the wind slackens off and suddenly you need to get a crapload of power from somewhere. You don't solve this problem with a slow base load station: this is an intermittent spike problem, you solve it with a fast-starting, cheap-to-idle supply like a gas plant. Which brings me to two points:
1) Who cares if there are a few jobs that renewables can't fill? Use fossil fuels to make up for their shortcomings. Insisting on a 100% renewable future is overly idealistic: I say, if we can fill 95% of our energy needs with renewables, go ahead, use natural gas or whatever when you need to. Don't let the perfect be the enemy of the good.
2) There are plenty of renewable forms of "gap-filling" energy. People have mentioned biomass burning. Here's another one: TFA quotes the "prote" as saying that "hydroelectric is maxed out." Well, it's not. It's maxed out as far as its *average* power output, because of limits on available water supply to the reservoirs. But we can get a lot more out of it if we use it to fill in the gaps left by solar and wind. Shut off the hydro plants during the day when the solar plants are running, run them twice as hard at night, and you're good to go. Need more nighttime power? Use solar electricity to run a pump to pump water *up* the dam into the reservoir in the daytime, then run the plants even harder at night. The gap-filling potential is almost unlimited.
3) The main reason modern-day "base load" is so high is because major industrial power users (aluminum smelters, etc) shut off operations during times of peak demand, when they get charged extra for electricity: they make up for it by sucking up cheap power in off-peak hours. Change the pricing structure, so they get charged extra whenever supply dwindles. I can guarantee you that if you tell an aluminum plant "Tomorrow night's gonna be calm: if you want wind power then, you're gonna have to pay triple per kWh", they'll stop the smelters tomorrow night.
4) There is one overall problem: I'm describing an electrical system with much more variability. Everything, from the hydro turbines and generators to the high-tension lines to the substations, has to be built to handle higher peak power draws. That costs money, but it's not a fundamental problem.
So, you're furious at Comcast for not providing four channels you admit you've never watched, and one special-interest channel that almost nobody's even *heard* of? Oh, and their ads are annoying? Damn, man, you got some serious grievances. I thought we were talking about internet service, not TV, anyway. The debate is "cable vs DSL" here, I doubt DSL is going to provide you with the Big Ten Network whatever that is.
Allow me to go Old Fogey on you. When I was a kid, we got PBS and CBS. That's it. And we liked it!
Bear in mind these are small differences: if you could make a perfect scale model of the sea-level surface the size of a billiard ball, it would be rounder and smoother than the ball.
Mind if be pedantic? Not quite true. The difference between pole and equatorial radii at sea level is 22 km. Add in the height of Mt Chimborazu and the depth of the ocean near the South Pole, and we find that Earth deviates from a sphere by about 33 km, and so it's spherical to within +/- 0.26%.
The Billiard Congress of America requires billiard balls to be 2.25" in diameter, to an accuracy of +/- 0.005", or +/-.022%.
So, the Earth doesn't quite pass muster as a billiard ball.
"Give me a pool cue large enough and a place to stand, and I shall sink the Earth in the corner pocket." -- Archimedes Fats
It was always awful, we just didn't have anything good (outside of print, anyway) to compare it to. Even the original Star Wars is just a subtlety-free retelling of The Hobbit with big explosions, but we needed a string of movies and tv shows from Star Trek: Next Generation to Enemy Mine to Babylon 5 to The Terminator to The Matrix to realize what good sci-fi storytelling was.
90% of IT professionals don't want to do more work.
I got a lot of respect for the IT guys who go the extra mile for their users, but there's no denying that migrating to Vista is going to involve a hell of a lot of effort, overtime, and disaster management. Even if the OS was the hottest thing since sliced bread, the best of the IT guys would sigh and grumble a bit, and the worst will actively stonewall.
In other news, a breakin and robbery was reported at 42 Elm Street after the owner gave his front door key to a gang member to hold for safekeeping. "He seemed like such a nice guy", said the owner.
I was a grad student at MIT during construction. You say:
"One of the things that seemed odd to me about the Stata is that it was often felt that something about Building 20 actually seemed to encourage creativity and collaborative work, and I've always wondered why MIT, Gehry at all didn't first make a serious study Building 20 to see how and why it worked before embarking on what frankly looks to me like a half-baked display of architectural egotism."
They did. Throughout the design and construction, they were *constantly* talking about "lessons learned from the old building 20", "preserving the ideals of the old building 20 in a modern space", on and on. Among other things, Building 20 was nice because it was so old that if you needed to rip out a wall, feel free. A friend of mine once needed some thick wiring for a project late at night, so he yanked a piece of unused conduit off the wall and cannibalized the building for parts. The Stata Center has some very large spaces with movable walls and flexible utilities, which can be repurposed and adapted in the same way.
The administration and architects seriously hyped the connection to the old Building 20. The reality doesn't quite match the hype, but they did make some effort.
Haven't used Enlightenment, but I've used X11 window managers with virtual screens a lot, and I had one for Mac OS back in the day. If by "sliding from desktop to desktop" you mean that you can switch from one screen to an adjacent one by moving the mouse "off the edge" of the screen, there's a really good reason Apple doesn't do that.
Apple pays attention to the interface design idea that says that edges and corners are good places to put stuff, because they're essentially infinitely big targets: you slam your mouse up to the edge of the screen, and don't have to aim precisely. That's why Apple's menu bar is at the top of the screen, and the Dock at the bottom (or sides). If hitting the edge of the screen pops you over to a new screen, then the menu bar is no longer an infinitely tall click target: it's a narrow strip which totally vanishes if you mouse up a pixel too high. Same for the dock.
Edge-sensitive virtual desktop systems drive me batty, I constantly try to click on stuff near the edge of the screen only to have it vanish. It's even more problematic on Macs, since the top edge of the screen is very important.
Also, the idea of tiling desktops into a regular grid that actually lines up pixel-for-pixel on corners and edges works great for a rectangular desktop. But Macs are designed to work well with multiple monitors at different resolutions, for which that tiling doesn't work.
I hate to pull rank here, but I have a bachelor's in physics and a PhD in climate physics, where I specialized in fluid mechanics. I'm not an aeronautical engineer, but I *have* heard of the Bernoulli effect before.
The bernoulli effect has a bit to do with explaining *how* the wing and air push on each other, but you can understand how a plane works without any fluid mechanics at all. Gravity is pulling the plane down. There must be a counteracting force holding it up. The air exerts this force on the wings. (How? You could mumble "bernoulli" at this point, but that's more detail than we need.) Newton's Third Law states that for every action, there is an equal and opposite reaction. The air pushes the plane up; the plane pushes the air down, with a force equal to the weight of the plane.
Airplanes *do* fly by pushing down on a bunch of air until they leave the ground. They just do it a little more subtly than a helicopter. Whether your book talks about them or not, Newton's laws always hold: if you still think I'm wrong, answer this question: "What pushes on the plane? Where is the equal and opposite reaction to that force?"
Wing vortexes and wake turbulence are often talked about as if they're minor inconveniences, little inaccuracies in the perfect equations for wing behavior, caused by little details like finite wing length and imperfect shape. Nothing could be further from the truth. If a wing passed through the air and left it completely undisturbed, as is usually drawn in popular science articles on aerodynamics, the wing would generate no lift. How could it? If no force has been exerted on the air, no force can be exerted on the plane, and the only force acting on it is gravity.
So one of the reasons they try to keep airplanes separated in the sky is because of the downward flow of air they generate behind them. For every action there's an equal and opposite reaction: if the air is lifting the plane, the plane must push the air down. If one plane flies too close to another, the downwash can cause the trailing plane to crash.
The wings of this thing generate a downwash at the top of the "paddle wheel" which flows down and strikes the wing at the bottom of the paddle wheel. Not one website discussing these planes mentions this. Maintaining control and lift in this situation sounds... challenging.
I suggest everyone read up on Igor Sikorskiy, the inventor (more or less) of the helicopter.
"You can't make a helicopter without ultrasonic and x-ray fracture inspection."
Well sure that makes it safer, but Sikorskiy didn't have any of that. Hell, I don't think they did that in the Vietnam era.
"You need 900 horsepower (or some damn thing) to make a working heli."
Sikorskiy's first helicopter ran on a 90-hp piston engine, with a welded steel frame.
It's true that this guy's helicopter is probably overweight, flying on ground-effect only, and it seems to be missing the most important (and complicated) part, the swashplate / cyclic blade control. But give him the resources Sikorkiy had, and I think he could do it.
If the system won't boot, you can plug it into a working computer to diagnose it. If you need to mirror the system files to a new drive, you can do so without any annoying "file in use" errors. If a system is so chock full of viruses and spyware that you can't even get anti-virus/anti-spyware software to run, you can just mount it as an external hard drive and run the scan from a working system.
As has been mentioned elsewhere, Macs' "target disk mode" lets you do pretty much all of this stuff. Maybe not your "if the system won't boot" case, but I'm not sure if TFA's solution will work in case of CPU, memory, or motherboard failure either.
Who boots a laptop? I just close the lid on my Mac, and it goes to sleep. I open it up and there's my stuff, in less time than it takes to plug in a cable. It'll sleep happily for weeks without running out of juice. The only time I ever reboot it is when it needs a software update.
TFA is an elaborate solution to the wrong problem. The right problem is, "how can we make laptops that don't need to be booted every time they're used?"
I bet New York, Chicago, Toronto and all the rest could have benefited from a city-leveling whollop a century ago as well.
What, like the Great Chicago Fire of 1871, the Great Toronto Fire of 1904, or the Great Fire of New York of 1835?
Sure, on a "fraction of citywide structures leveled" scale, Halifax was more significant than Toronto or New York's fires (thought not Chicago's), but I don't think you can pin the blessings or sins of that city on a single explosion.
Slashdot Mirror
Imagine if Kennedy, in his 1961 State of the Union address, said he was going to invest billions in forming a massive group of scientists and engineers, and get them to do "I dunno, something cool." You think it would have resulted in a moon landing?
Imagine if an entrepreneur went to an investor asking for startup funding, with a beautiful Powerpoint showing innovative new organizational charts, an efficient supply chain, and a great advertising theme. "What are you going to make?" "I dunno, something cool."
If you want to make a great free-software game, come up with a great game idea first, and then gather some free-software resources to make it happen. Planning the administrative and legal issues before coming up with a product concept is the fast-track to mission failure.
Buy a Mac with OS 10.5 on it.
Buy an external hard disk.
Plug it in.
Done!
This "poll" was done by show of hands in a large lecture hall. As a college professor, let me tell you: unless you're a very good teacher, the number of students in a college class who'll raise their hands when asked *any* question, up to and including "do you have a pulse?" is 2. Doesn't matter how big the class is: if it's a 2 person class, both will raise their hands. In a 500-person class, it's still 2, 'cause 300 of them aren't paying attention, and 198 are chicken.
Lemme see here. Just off the top of my head:
Capacitance.
Ultrasound.
Light refraction.
Light reflection.
Slosh frequency.
Mechanical floats.
Six ways to measure the amount of gas in the tank without putting anything in the tank.
*Holds out hand*
PATENTS PLEASE!
Parent is the only post in this thread worth reading.
If your deorbit burn is off by even a tiny fraction of a percent, you'll be splashing down in the south side of Chicago. And believe me, that's no place to park a billion-dollar spacecraft.
We're past the 24-hour "nobody cares" limit on Slashdot, but if anybody's still listening, mod parent up for bothering to do the math, even if he disagrees with me.
Another poster pointed out that your area math is wrong: the actual area comes to a patch of ground about 70 km on a side, proportionally more if you assume imperfect sunlight->electricity conversion. It's a sizeable patch of ground, but I'm sure we could find a few nice patches of desert or open ocean to park this on.
As for Hoover Dam: it only puts out 2 gigawatts because if it put out more, Lake Mead would run dry. So the clever designers only put in a few turbines. That's not a problem in this case, since we're refilling the lake every day. There's no problem in principle with installing *ten times* as many turbines and ten times as many generators. We drain the lake ten times as fast at night, and then fill it back up the next day.
Suppose we take the ten largest dams in the U.S. and assume they're all about like Hoover Dam. (In practice, we'd probably split the load among dozens of dams.) Each of these ten dams needs to supply 20 gigawatts of power at night.
Each dam needs to supply 20 gigawatts x 12 hours = about 9e14 joules of energy. Lake Mead holds 35 cubic kilometers of water, or 35e12 kilograms. The gravitational potential energy of the lake is about 35e12 kg * 9.8 * 200 m = 7e16 joules.
SO, if we install ten times as many generators in Hoover Dam, add a whole bunch of pumps, and repeat this setup at the ten largest dams in the country, we can handle the entire nighttime electrical load, and only drain 1% of the volume of each reservoir each day. Problem solved.
Added bonus: the Colorado River might run backwards from time to time, which means you can do an all-day whitewater rafting trip and end up back at your car!
Whoa, hang on a second. Five megabytes is the same storage as a nice two-volume set of hardcover books. Seek time of 600 milliseconds is only one order of magnitude less than the time it takes me to look up something in an index.
And the cost? Maybe a buck or two for the books, compared to 3200 per month in 1956.
So what advantage do these suckers have over a couple of big books, even in 1956?
If the "seek time" advantage is so crucial, use a RAID-0 system. Get ten girls from the typing pool to look through 10 books, giving you 10 answers at a time. It'll still cost less than $3200 per month.
At least 20 times in this discussion, someone's said "Give a man a fish, he has food for a day; teach a man to fish, he has food for a lifetime."
Nowhere in there does it say "give a man's kid a computer, and he'll have food for a lifetime." What the kid will have is a fancy gadget that he has no idea how to use, that does almost nothing to help his daily life, and that has zero connectivity or compatibility with the way the rest of the computerized world works (and I say that as a Mac user.) Someone here bragged about a special button on the keypad that enables source code editing of the current application. 99.9% of American kids would have no idea what to do with that, and they've got a titanic advantage in technical expertise from the get-go.
How about, y'know, teaching people to fish? Well, actually, they already know how to fish. Buy 'em a boat that works, so they can actually do some fishing. Get a bunch of 'em to work on building a good road to the capital city. Buy a dozen of them a delivery truck each, so they can deliver food in to town, and buy one the tools and training he needs to repair the trucks. For more developed areas, scale it up: help someone start a small manufacturing shop, a textile mill, a hydro power plant, a computer store. Provide capital equipment and infrastructure to help them take one technological step up at a time.
OLPC makes the same mistake that Dvorak does: they fail to see "progress" as the gradual development of an interconnected, self-maintaining infrastructure, in which each person helps to build, maintain, and develop stuff needed by someone else. The broader and deeper that network, the more successful the society. Dropping stuff out of the sky, whether it's high-tech computer or sacks of food, does nothing to develop that web.
"Base load" is a bad phrase to use for this issue (to the extent it's an issue). Today, the base load is the electrical demand that's always there, 24/7. It's met by sources like coal and oil and nuclear that can't be started or stopped slowly (or are just too expensive to allow to sit idle); we've got stuff like natural gas plants that we switch on quickly to meet the occasional peak in demand. In a renewable energy future, the problem is that occasionally, it's nighttime and the wind slackens off and suddenly you need to get a crapload of power from somewhere. You don't solve this problem with a slow base load station: this is an intermittent spike problem, you solve it with a fast-starting, cheap-to-idle supply like a gas plant. Which brings me to two points:
1) Who cares if there are a few jobs that renewables can't fill? Use fossil fuels to make up for their shortcomings. Insisting on a 100% renewable future is overly idealistic: I say, if we can fill 95% of our energy needs with renewables, go ahead, use natural gas or whatever when you need to. Don't let the perfect be the enemy of the good.
2) There are plenty of renewable forms of "gap-filling" energy. People have mentioned biomass burning. Here's another one: TFA quotes the "prote" as saying that "hydroelectric is maxed out." Well, it's not. It's maxed out as far as its *average* power output, because of limits on available water supply to the reservoirs. But we can get a lot more out of it if we use it to fill in the gaps left by solar and wind. Shut off the hydro plants during the day when the solar plants are running, run them twice as hard at night, and you're good to go. Need more nighttime power? Use solar electricity to run a pump to pump water *up* the dam into the reservoir in the daytime, then run the plants even harder at night. The gap-filling potential is almost unlimited.
3) The main reason modern-day "base load" is so high is because major industrial power users (aluminum smelters, etc) shut off operations during times of peak demand, when they get charged extra for electricity: they make up for it by sucking up cheap power in off-peak hours. Change the pricing structure, so they get charged extra whenever supply dwindles. I can guarantee you that if you tell an aluminum plant "Tomorrow night's gonna be calm: if you want wind power then, you're gonna have to pay triple per kWh", they'll stop the smelters tomorrow night.
4) There is one overall problem: I'm describing an electrical system with much more variability. Everything, from the hydro turbines and generators to the high-tension lines to the substations, has to be built to handle higher peak power draws. That costs money, but it's not a fundamental problem.
So, you're furious at Comcast for not providing four channels you admit you've never watched, and one special-interest channel that almost nobody's even *heard* of? Oh, and their ads are annoying? Damn, man, you got some serious grievances. I thought we were talking about internet service, not TV, anyway. The debate is "cable vs DSL" here, I doubt DSL is going to provide you with the Big Ten Network whatever that is.
Allow me to go Old Fogey on you. When I was a kid, we got PBS and CBS. That's it. And we liked it!
Bear in mind these are small differences: if you could make a perfect scale model of the sea-level surface the size of a billiard ball, it would be rounder and smoother than the ball.
.022%.
Mind if be pedantic? Not quite true. The difference between pole and equatorial radii at sea level is 22 km. Add in the height of Mt Chimborazu and the depth of the ocean near the South Pole, and we find that Earth deviates from a sphere by about 33 km, and so it's spherical to within +/- 0.26%.
The Billiard Congress of America requires billiard balls to be 2.25" in diameter, to an accuracy of +/- 0.005", or +/-
So, the Earth doesn't quite pass muster as a billiard ball.
"Give me a pool cue large enough and a place to stand, and I shall sink the Earth in the corner pocket." -- Archimedes Fats
It was always awful, we just didn't have anything good (outside of print, anyway) to compare it to. Even the original Star Wars is just a subtlety-free retelling of The Hobbit with big explosions, but we needed a string of movies and tv shows from Star Trek: Next Generation to Enemy Mine to Babylon 5 to The Terminator to The Matrix to realize what good sci-fi storytelling was.
Mod parent higher than TFA, please.
90% of IT professionals don't want to do more work.
I got a lot of respect for the IT guys who go the extra mile for their users, but there's no denying that migrating to Vista is going to involve a hell of a lot of effort, overtime, and disaster management. Even if the OS was the hottest thing since sliced bread, the best of the IT guys would sigh and grumble a bit, and the worst will actively stonewall.
In other news, a breakin and robbery was reported at 42 Elm Street after the owner gave his front door key to a gang member to hold for safekeeping. "He seemed like such a nice guy", said the owner.
"One of the things that seemed odd to me about the Stata is that it was often felt that something about Building 20 actually seemed to encourage creativity and collaborative work, and I've always wondered why MIT, Gehry at all didn't first make a serious study Building 20 to see how and why it worked before embarking on what frankly looks to me like a half-baked display of architectural egotism."
They did. Throughout the design and construction, they were *constantly* talking about "lessons learned from the old building 20", "preserving the ideals of the old building 20 in a modern space", on and on. Among other things, Building 20 was nice because it was so old that if you needed to rip out a wall, feel free. A friend of mine once needed some thick wiring for a project late at night, so he yanked a piece of unused conduit off the wall and cannibalized the building for parts. The Stata Center has some very large spaces with movable walls and flexible utilities, which can be repurposed and adapted in the same way.
The administration and architects seriously hyped the connection to the old Building 20. The reality doesn't quite match the hype, but they did make some effort.
Haven't used Enlightenment, but I've used X11 window managers with virtual screens a lot, and I had one for Mac OS back in the day. If by "sliding from desktop to desktop" you mean that you can switch from one screen to an adjacent one by moving the mouse "off the edge" of the screen, there's a really good reason Apple doesn't do that.
Apple pays attention to the interface design idea that says that edges and corners are good places to put stuff, because they're essentially infinitely big targets: you slam your mouse up to the edge of the screen, and don't have to aim precisely. That's why Apple's menu bar is at the top of the screen, and the Dock at the bottom (or sides). If hitting the edge of the screen pops you over to a new screen, then the menu bar is no longer an infinitely tall click target: it's a narrow strip which totally vanishes if you mouse up a pixel too high. Same for the dock.
Edge-sensitive virtual desktop systems drive me batty, I constantly try to click on stuff near the edge of the screen only to have it vanish. It's even more problematic on Macs, since the top edge of the screen is very important.
Also, the idea of tiling desktops into a regular grid that actually lines up pixel-for-pixel on corners and edges works great for a rectangular desktop. But Macs are designed to work well with multiple monitors at different resolutions, for which that tiling doesn't work.
I hate to pull rank here, but I have a bachelor's in physics and a PhD in climate physics, where I specialized in fluid mechanics. I'm not an aeronautical engineer, but I *have* heard of the Bernoulli effect before.
The bernoulli effect has a bit to do with explaining *how* the wing and air push on each other, but you can understand how a plane works without any fluid mechanics at all. Gravity is pulling the plane down. There must be a counteracting force holding it up. The air exerts this force on the wings. (How? You could mumble "bernoulli" at this point, but that's more detail than we need.) Newton's Third Law states that for every action, there is an equal and opposite reaction. The air pushes the plane up; the plane pushes the air down, with a force equal to the weight of the plane.
Airplanes *do* fly by pushing down on a bunch of air until they leave the ground. They just do it a little more subtly than a helicopter. Whether your book talks about them or not, Newton's laws always hold: if you still think I'm wrong, answer this question: "What pushes on the plane? Where is the equal and opposite reaction to that force?"
Wing vortexes and wake turbulence are often talked about as if they're minor inconveniences, little inaccuracies in the perfect equations for wing behavior, caused by little details like finite wing length and imperfect shape. Nothing could be further from the truth. If a wing passed through the air and left it completely undisturbed, as is usually drawn in popular science articles on aerodynamics, the wing would generate no lift. How could it? If no force has been exerted on the air, no force can be exerted on the plane, and the only force acting on it is gravity.
So one of the reasons they try to keep airplanes separated in the sky is because of the downward flow of air they generate behind them. For every action there's an equal and opposite reaction: if the air is lifting the plane, the plane must push the air down. If one plane flies too close to another, the downwash can cause the trailing plane to crash.
... challenging.
The wings of this thing generate a downwash at the top of the "paddle wheel" which flows down and strikes the wing at the bottom of the paddle wheel. Not one website discussing these planes mentions this. Maintaining control and lift in this situation sounds
I suggest everyone read up on Igor Sikorskiy, the inventor (more or less) of the helicopter.
"You can't make a helicopter without ultrasonic and x-ray fracture inspection."
Well sure that makes it safer, but Sikorskiy didn't have any of that. Hell, I don't think they did that in the Vietnam era.
"You need 900 horsepower (or some damn thing) to make a working heli."
Sikorskiy's first helicopter ran on a 90-hp piston engine, with a welded steel frame.
It's true that this guy's helicopter is probably overweight, flying on ground-effect only, and it seems to be missing the most important (and complicated) part, the swashplate / cyclic blade control. But give him the resources Sikorkiy had, and I think he could do it.
If the system won't boot, you can plug it into a working computer to diagnose it. If you need to mirror the system files to a new drive, you can do so without any annoying "file in use" errors. If a system is so chock full of viruses and spyware that you can't even get anti-virus/anti-spyware software to run, you can just mount it as an external hard drive and run the scan from a working system.
As has been mentioned elsewhere, Macs' "target disk mode" lets you do pretty much all of this stuff. Maybe not your "if the system won't boot" case, but I'm not sure if TFA's solution will work in case of CPU, memory, or motherboard failure either.
Who boots a laptop? I just close the lid on my Mac, and it goes to sleep. I open it up and there's my stuff, in less time than it takes to plug in a cable. It'll sleep happily for weeks without running out of juice. The only time I ever reboot it is when it needs a software update.
TFA is an elaborate solution to the wrong problem. The right problem is, "how can we make laptops that don't need to be booted every time they're used?"
I bet New York, Chicago, Toronto and all the rest could have benefited from a city-leveling whollop a century ago as well.
What, like the Great Chicago Fire of 1871, the Great Toronto Fire of 1904, or the Great Fire of New York of 1835?
Sure, on a "fraction of citywide structures leveled" scale, Halifax was more significant than Toronto or New York's fires (thought not Chicago's), but I don't think you can pin the blessings or sins of that city on a single explosion.
That's one small step for accuracy, one giant leap for annoying pedantry.