As other people have said: welding it is not easy. (Though, in MY opinion, it's easier than aluminum, and with good equipment, steel, ti, and al are all pretty easy.)
As other people don't seem to have said: titanium is, AFAIK, the only metal that burns in both oxygen *and* nitrogen. If you've ever seen magnesium burn, it's reacting very violently with the 20% of oxygen in the atmosphere. Titanium's far worse. And it's difficult to extinguish metal fires.
A: I've yet to try anything that was even remotely like good beer, despite having tried dozens of types (although my then-girlfriend's homebrewed coffee beer was *unusually* bad)
B: I'm a jock, basically, so, y'know, it kind of comes with the territory.
>People trust "media" to the extent they don't have expertise in some subject matter. What other result would you expect?
I think that's a critically important observation, and if you extrapolate a little you get to an uncomfortable realization: people look for news that reaffirms what they want to hear. With the proliferation of news sources, you can find specialized news feeds, and end up with a situation where hundreds of thousands of Americans believe we found WMD's in Iraq -- because the repeated message becomes true. And if the news source you're listening to says what you want to hear (and why wouldn't it? coz that's why you chose to listen to them, after all) you're less likely to question it, and you have a positive feedback loop for isolation and polarization of groups of society. I wish I knew a way to avoid this situation, but I don't think it's repairable.
"He's not a hacker, he's a *cracker*! Hackers are the good guys!"
"Why does this ounce of gold weigh more than that ounce of iron?"
Or even: "when you push on the throttle, you're NOT actually 'giving it the gas'."
Mainstream communication relies on abbreviations, poor summaries, and outright incorrect definitions of words, that appall specialists. CS people do it, and law people do it. I think one difference might be that law people have been doing it for 2000 years, so they have a bit of a head start on specializing their language.
I just read an interesting book about life in Mumbai, called "Maximum City". One of the things the guy who wrote it mentioned is that when he moved (back) to Mumbai after having been gone for ten years, he rented an apartment for $5000/month, with a $200,000 deposit. It took him three months after getting the apartment before he had water, power, and gas, and even then, neither the water nor the power were anywhere like 24/7. Now, he got a reasonably good apartment for that money, compared to the hundreds of people who were living in tents and illegal buildings (that were regularly knocked down by the government) that were all around his apartment building, but still: you'd have to make quite a bit of money to live like a king in the most populated city in India.
I entirely agree with you. But there are lots of people who don't. A friend of mine posted something about Guantanamo on her blog and had tens of people saying, in effect, that they had no problem whatsoever with innocent people being imprisoned, tortured, and killed, if there was even a chance that some of those people might be terrorists.
That breaks my brain. Once you make that leap, then *everyone* is your enemy and you grab a gun and just start shooting until there's nobody left, to keep yourself safe.
Which, basically, is what the USA is doing in the world at large. There are lots of people who don't see a problem with this, maybe even a majority of Americans.
That's a great idea! You can get well over 5 atm with a bicycle pump, but it's making something that can contain 5 atm and still be safe, that's a challenge. The same thing should work with a 2L pop bottle, which seem to be able to handle about 8 atm or so, but I've never heard of anyone who's actually done it. I'll have to go try it.
I kind of figured, since you obviously know what CO2 is. But hey, you're in good company: in "Real Genius" at one point one of the characters is holding (with gloves) a chunk of icy material and when someone asks him what it is, he says "liquid nitrogen". Ooops!
(As a side note: you can't play with liquid CO2, at least not on Earth. It's either solid or gas, coz you need about 5 atmospheres of pressure for it to be liquid.)
Dry ice is fun. If you buy a dewar from somewhere like Edmund or sometimes American Surplus And Science (amsci.com) you might be allowed to buy liquid nitrogen from a local welding supply place. There are scads of online instructions for making instant ice cream with liquid nitrogen. If you're *really* careful, there are lots of other fun things to do with it: blow up balloons and press them flat as pancakes in the LN2, then sail one like a frisbee and, if you do it right, it'll warm up and pop back into an inflated balloon in the air.
I used to work at the Litle Shop Of Physics and they have lots of suggestions about silly projects you can do, that illustrate basic science, or weird science. A lot of them use things like 2L bottles with aluminum foil wrapped around them, filled with salt water, as Leyden jars, charged by putting aluminum foil on TV screens -- you can get 30,000 volts from that and load up 50 Leyden jars and have a big chunk of power for some exciting projects.
Scitoys has lots of neat projects. I built a set of Franklin's Bells (Ben Franklin invented them to warn of oncoming lightning storms) that are functionally identical to the scitoys version (tho' I'd thought it up on my own) and that's a quick, funny project. Actually, looking around on their site, you could spend the rest of your life just building and playing with what they have. I think someone wrote a book called Gonzo Gizmos that's based on what they've done, and it's fantastic. The audio-via-laser-pointer is really easy to set up (hint: use the smallest solar cell you can find or a photodetector that the laser pointer beam nearly entirely covers, to get a better signal/noise ratio) and a lot of fun to play with.
You'll notice I'm not talking much about chemistry. There's some superb stuff to do there (speaking as a person with a degree in chemistry) but it is, simply, more dangerous, and it behooves you to know what you're doing before you let your kids do stuff. My dad made seriously dangerous stuff, like stuff that left pieces of copper embedded in some of his friends' internal organs, and while that's great fun and all, wait until your kids are a couple years older.
Did I mention how much fun you can have with microwaves? Particularly if you don't care about them very much? Neon bulbs are cheap. Put some in the microwave and turn it on. Microwave CD's. Microwave marshmallow peeps. Have grape races. Butterfly a grape to form a dipole antenna and watch it vaporize. You can even melt silver in a microwave (tho' I have yet to actually try this.)
This isn't in the same realm as USB bridges... but it's sure made my life better.
At my work, we produce power converters: put some arbitrary voltage into this chip, and it produces a precise, fixed voltage. They're what turns a cellphone battery's power into what's needed by the display, backlight, processor, and transmitter, frinstance. The efficiency of a converter is what determines how long the battery lasts, and it's measured by how much power comes out compared to how much went in. We quantify this by supplying a range of input voltages, and for each one, varying the output current -- the demand. Since we can measure the input current, and we know the output voltage, the output voltage * current, divided by the input voltage * current, is the efficiency. From this we can derive a three-dimensional curve, a surface, showing the efficiency at each point within the operational voltage/current limits. Doing a thousand of these measurements and writing the value for each point, takes a couple of days to produce a reasonably high-resolution curve. Which we had an apps engineer doing, by hand, to a predetermined accuracy. What I wrote does the same thing in two hours, using a stack of power supplies, power sinks, and multimeters, all hooked up by GPIB, but there's a sticking point.
Electricity has two facets: amperage, which is basically how many electrons are flowing, and voltage, which is a measure of each electron's energy. Amps aren't lost: you don't have electrons getting stuck in corners and not coming back out. Voltage, however, IS lost. That's the whole point of voltage, essentially: when you plug something in, you're changing the volts into work and heat, and returning the used electrons, the amps, to the power company to be recycled. So when I want to measure efficiency and I put a certain voltage into a power converter, some of that voltage is lost in the wires themselves, heating them up. I tell the power supply to produce 5 volts, and it does, but the load at the other end of the wires may only receive 4.8 volts. That doesn't sound like such a big deal, but it's 4%, and when your system is 92% efficient and someone else's is 96% efficient, guess whose system gets purchased?
To account for this, I could either use short, fat wires from the power supply -- like jumper cables, short fat wires lose less voltage -- or I can measure the voltage right at the converter, and know what it's actually using. Even better, I can build a closed-loop feedback system, where I tell the power supply to produce 5 volts, measure what's actually being delivered, then tell the power supply to raise its voltage until I'm getting what I originally wanted. Then I don't care about wires. So that's what I did, and to make it even neater I wrote a software controller that optimizes the loop response -- it closes in on what I want like an informational homing torpedo. It's neat to watch, especially when I consider how long it takes to do this by hand. Especially when I've done it by hand, for two days.
You might be interested in knowing that MS Excel, despite its claims, only seems to have one good way to do graphic display of 3-D information: a pivot table from which a surface chart takes its data. It took me forever to figure that out because it doesn't seem to be listed anywhere in the help files. But if I set up the output from the measurement system as tab-delimited outputs of the form:
\t\tOscars \tRazzies \tScuzzies\n
hanks \t5 \t3 \t2\n
roberts \t7 \t3 \t4\n
cruise \t2 \t5 \t9\n
excel chews it up and makes a lovely graph, from which we can see where the converter's poles and nodes are, and get a measurement of capacitor quality and loss across the diode that's 1/3 of a good switching power supply (and its major source of efficiency loss at low input voltages.)
For the record, it's written in MatLab but I'm moving it over to a C script with plotting in GNUplot.
I'm going with Mistshadow2k4 on this: you've clearly never actually worked. My last job, we didn't have the internet, we didn't have TV's, we didn't get potty breaks except federally mandated 15 minute breaks in the morning and evening. I was a tech so I actually had access to a phone; the assembly people had one hour per ten hour shift where they were not required to be in their seats working. (thirty minutes for lunch, timed, with punchcards; two fifteen minute breaks, timed, with punchcards.) Talking was *strongly* discouraged. Stuff was coming down the line at the same rate the entire shift unless something broke, and if you fell behind, everyone knew who was at fault. We worked 10 hours a day, six days a week, and some Sundays, and if you didn't show up, even if you were sick and called in, you were fired.
It sucked more than I can say. Everyone there hated it. But boy were we productive.
For neutral or negative stability aircraft, fly-by-wire is necessary, and even for commercial aircraft it's a big help. (I've gotten a little time in a very big airplane that predates servo/hydraulic systems, and let me tell you, it's no joke. Commercial pilots in the '40's must've been pretty muscular.)
The difference is: that's something close to a linear function, and can be modelled and turned into a few lines of software, in the case of a transport aircraft, or some DSP code for a negative-stability aircraft. It can be tested over the entire range of possible inputs and outputs: it can be entirely quantified. That's not the case with autopilots and collision avoidance systems: the feedback/feedforward and even just the number of variables completely exceeds any hope of exhaustive testing. That means, in order for it to work, it has to have sanity, a sense of what's right and wrong, and as of yet we haven't managed to write code that does that reliably.
>I've often sort of wondered if Roy knew Deckard was a replicant.
That's been my assumption. Roy and Rachel both considered Deckard to be at least some type of equal.
(by the way, the 'if Deckard's a replicant, why did he get the crap beat out of him' question could also be asked of Rachel during the, well, date rape scene, for lack of a better way of dealing with that unsettling bit. I've assumed in the past that since Deckard doesn't know he's a replicant but does know she is, that's some weird sort of assertion of himself -- since he can't bring himself to kill her, he rapes her instead, as an assertion of power.)
So, in the book, there were almost no actual animals in the world: sheep were unbelievably valuable. I've often wondered if, in the movie, most all the humans were actually replicants, if humans were as rare as all the other animals and it was only Tyrell and a few others, who were repopulating the whole world with replicants, and nobody knew.
Given that today's front-page-top-center-headline is "Incidents Prompt New Scrutiny Of Airplane Software Glitches" and the accompanying article discusses a number of autopilot problems that have led to uncontrolled/out-of-control situtions on commercial jets during flight.
There are rules for avoiding collisions. In-flight collisions among commercial traffic are unbelievably rare in the First World because pilots don't generally BSOD or have their sensors start giving them false information. (To be more precise, they're trained to understand the quality of information their instruments are giving them, and decide when to stop trusting that information.)
Software can clearly fly planes, and fly them safely. It also clearly isn't managing to do so yet and until we can write software that's better than two pilots we shouldn't be putting it in aircraft.
And I meant to mention that drug-runners thought they'd scored gold when the first all-composite homebuilts, like Burt Rutan's (of SpaceShipOne fame) EZ and Long-EZ, started hitting the used aircraft market. Composites! Invisible to radar! Except the engines, all covered in sharp little edges and corners, stood out like beacons for radar, better (according to a radar tech friend of mine) than a smoothly-covered metal aircraft. Plus the homebuilts often had less cargo space so they didn't do very well for high-volume contraband. Ooops.
Raytheon developed a radar system that used reflections from commercial TV and radio transmissions to track objects. It worked pretty well but the US government wasn't interested in funding it... that is until China developed something similar. Both can give reasonably good positioning -- good enough for a missile to launch (after which point, presumably, it'll be doing its own tracking) without exposing the missile launcher to pre-launch suppression fire. Several newer systems have used GPS signals to do the same thing, which is really difficult, given how weak the signals are, but you can always rely on at least some GPS signals, while commercial TV/radio might not be operational.
Many of the stealth planes use facets to make big specular reflections of radar signals, on the theory that you're much less likely to pick up a huge narrow bounce than a much lower-level, omnidirectional bounce. This is used in both the B2 and the F117, but both also use paint that contains radar-absorptive paint, as I recall.
One of the early anti-radar setups ran into an interesting problem: the signal they got from the mounting hardware completely overwhelmed the signal they got from the stealth airframe so they couldn't easily measure improvements. I've read that it is precisely this attention to detail -- edges, screw heads (and the slots for screwdrivers) and the like, that show up on radar when the bulk body has been disguised.
Early radar operators in England kept detecting what they called 'angels' and after the war they realized they were picking up flocks of birds. In the '70's the local air traffic control center could easily pick up and distinguish between different truck sizes on the interstate highway 20 miles to their east, which was a problem for distinguishing low-flying aircraft in the small (non-ATC, so not THAT much of a problem) airports beside and near the interstate.
My girlfriend bought copies of Tomb Raider I and II and Gia not because they were good movies -- they're complete and utter crap -- but because each one had a scene or two that showed off some of Angelina Jolie's, uh, assets. My gf bought them all at a used store, not caring that one was scratched ("as long as it's not scratched during the money shot") and says they're utter crap, would never buy them for full price, blah blah blah.
The point being: just because something is utter, mindless tripe doesn't mean that a bit of it might not have value to someone. However, if you think something is mindless crap, it's really hard to convince yourself to pay full price for it.
I think one of the reasons ITunes is so popular is it allows you to winnow. I like MC 900 Foot Jesus, but there's only one song of theirs I'd actually pay for. As weird a thought as this may seem, it's quite possible that people might buy scenes from movies, where if they can only get the whole movie they can't bring themselves to pay for it, so they acquire it. Look at Windows: no way in hell I could convince myself to pay retail price, but I have a copy so I can run Photoshop.
Note that I'm not saying it's right, or that it's any justification whatsoever for copyright infringement. It's not. All I'm talking about here is the psychology of the situation, and why people might have stuff they, themselves, consider worthless, in violation of copyright.
We gritted our teeth and slid them apart. They were trashed already, but that process didn't do them any good whatsoever. If I *had* to get them apart, without damage, I think I'd try putting them under a vacuum with one attached to something and the other hanging; when the water between them, or its dissolved gases, starts to boil they'd come right apart without damaging them, and gravity would keep them separate.
I know some of the people who originally did the research that discovered (and quantified) the mechanism for how geckos stick to walls. They also have done research on how gecko feet self-clean because sticky substances innately pick up debris that make them not-sticky. TFA has people making sticky stuff, but to the best of my knowledge they haven't yet gotten the self-cleaning aspect down, which is going to limit their long-term usefulness.
(from the article I linked: "Contact mechanical models suggest that self-cleaning occurs by an energetic disequilibrium between the adhesive forces attracting a dirt particle to the substrate and those attracting the same particle to one or more spatulae. We propose that the property of self-cleaning is intrinsic to the setal nanostructure and therefore should be replicable in synthetic adhesive materials in the future.")
As Anonymous Coward said, even the comparatively rough gauge blocks used in machining setup can be wrung together, which is traditionally done by touching one of them to your inner (not-so-hairy) arm to get some perspiration or oil, then placed against the other and pressed/turned. They *stick* like magnets. You see the same thing with wet microscope slides. All you need is enough flatness to let the applied water form a capillary film between the surfaces, so increasing the flatness quality reduces the amount of water needed until at some point, like with the gravity detector's mirrors, just the water layer formed by being exposed to humid air is sufficient to form a pretty impressively strong bond. I've worked with laser optics that are flat to within a half-wavelength of visible light, and they really like being together.
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As other people have said: welding it is not easy. (Though, in MY opinion, it's easier than aluminum, and with good equipment, steel, ti, and al are all pretty easy.)
As other people don't seem to have said: titanium is, AFAIK, the only metal that burns in both oxygen *and* nitrogen. If you've ever seen magnesium burn, it's reacting very violently with the 20% of oxygen in the atmosphere. Titanium's far worse. And it's difficult to extinguish metal fires.
A: I've yet to try anything that was even remotely like good beer, despite having tried dozens of types (although my then-girlfriend's homebrewed coffee beer was *unusually* bad)
B: I'm a jock, basically, so, y'know, it kind of comes with the territory.
iPod plays great tunes and lousy video. Beer tastes like jock armpit. The only surprise is that it was such a close race.
>People trust "media" to the extent they don't have expertise in some subject matter. What other result would you expect?
I think that's a critically important observation, and if you extrapolate a little you get to an uncomfortable realization: people look for news that reaffirms what they want to hear. With the proliferation of news sources, you can find specialized news feeds, and end up with a situation where hundreds of thousands of Americans believe we found WMD's in Iraq -- because the repeated message becomes true. And if the news source you're listening to says what you want to hear (and why wouldn't it? coz that's why you chose to listen to them, after all) you're less likely to question it, and you have a positive feedback loop for isolation and polarization of groups of society. I wish I knew a way to avoid this situation, but I don't think it's repairable.
>which is why prices in less able countries are adjusted according to what they'll pay.
Or, to put it another way, corporations like outsourcing when it's manufacturing, but don't like outsourcing when it's done by consumers.
"He's not a hacker, he's a *cracker*! Hackers are the good guys!"
"Why does this ounce of gold weigh more than that ounce of iron?"
Or even: "when you push on the throttle, you're NOT actually 'giving it the gas'."
Mainstream communication relies on abbreviations, poor summaries, and outright incorrect definitions of words, that appall specialists. CS people do it, and law people do it. I think one difference might be that law people have been doing it for 2000 years, so they have a bit of a head start on specializing their language.
I just read an interesting book about life in Mumbai, called "Maximum City". One of the things the guy who wrote it mentioned is that when he moved (back) to Mumbai after having been gone for ten years, he rented an apartment for $5000/month, with a $200,000 deposit. It took him three months after getting the apartment before he had water, power, and gas, and even then, neither the water nor the power were anywhere like 24/7. Now, he got a reasonably good apartment for that money, compared to the hundreds of people who were living in tents and illegal buildings (that were regularly knocked down by the government) that were all around his apartment building, but still: you'd have to make quite a bit of money to live like a king in the most populated city in India.
I hope you're right that it's a minority, I really do. I'm just not sure I believe it.
But yes, you're right. We trust our elected proxies, and apparently that isn't a good idea right now.
I entirely agree with you. But there are lots of people who don't. A friend of mine posted something about Guantanamo on her blog and had tens of people saying, in effect, that they had no problem whatsoever with innocent people being imprisoned, tortured, and killed, if there was even a chance that some of those people might be terrorists.
That breaks my brain. Once you make that leap, then *everyone* is your enemy and you grab a gun and just start shooting until there's nobody left, to keep yourself safe.
Which, basically, is what the USA is doing in the world at large. There are lots of people who don't see a problem with this, maybe even a majority of Americans.
That Petrowski book was the first thing I thought of when I saw the article, too. I love the picture on the front cover.
That's a great idea! You can get well over 5 atm with a bicycle pump, but it's making something that can contain 5 atm and still be safe, that's a challenge. The same thing should work with a 2L pop bottle, which seem to be able to handle about 8 atm or so, but I've never heard of anyone who's actually done it. I'll have to go try it.
I kind of figured, since you obviously know what CO2 is. But hey, you're in good company: in "Real Genius" at one point one of the characters is holding (with gloves) a chunk of icy material and when someone asks him what it is, he says "liquid nitrogen". Ooops!
I hope the projects work well for you.
(As a side note: you can't play with liquid CO2, at least not on Earth. It's either solid or gas, coz you need about 5 atmospheres of pressure for it to be liquid.)
Dry ice is fun. If you buy a dewar from somewhere like Edmund or sometimes American Surplus And Science (amsci.com) you might be allowed to buy liquid nitrogen from a local welding supply place. There are scads of online instructions for making instant ice cream with liquid nitrogen. If you're *really* careful, there are lots of other fun things to do with it: blow up balloons and press them flat as pancakes in the LN2, then sail one like a frisbee and, if you do it right, it'll warm up and pop back into an inflated balloon in the air.
I used to work at the Litle Shop Of Physics and they have lots of suggestions about silly projects you can do, that illustrate basic science, or weird science. A lot of them use things like 2L bottles with aluminum foil wrapped around them, filled with salt water, as Leyden jars, charged by putting aluminum foil on TV screens -- you can get 30,000 volts from that and load up 50 Leyden jars and have a big chunk of power for some exciting projects.
Scitoys has lots of neat projects. I built a set of Franklin's Bells (Ben Franklin invented them to warn of oncoming lightning storms) that are functionally identical to the scitoys version (tho' I'd thought it up on my own) and that's a quick, funny project. Actually, looking around on their site, you could spend the rest of your life just building and playing with what they have. I think someone wrote a book called Gonzo Gizmos that's based on what they've done, and it's fantastic. The audio-via-laser-pointer is really easy to set up (hint: use the smallest solar cell you can find or a photodetector that the laser pointer beam nearly entirely covers, to get a better signal/noise ratio) and a lot of fun to play with.
You'll notice I'm not talking much about chemistry. There's some superb stuff to do there (speaking as a person with a degree in chemistry) but it is, simply, more dangerous, and it behooves you to know what you're doing before you let your kids do stuff. My dad made seriously dangerous stuff, like stuff that left pieces of copper embedded in some of his friends' internal organs, and while that's great fun and all, wait until your kids are a couple years older.
Did I mention how much fun you can have with microwaves? Particularly if you don't care about them very much? Neon bulbs are cheap. Put some in the microwave and turn it on. Microwave CD's. Microwave marshmallow peeps. Have grape races. Butterfly a grape to form a dipole antenna and watch it vaporize. You can even melt silver in a microwave (tho' I have yet to actually try this.)
I haven't finished porting the data-collection part, so I'll take a look at that before I work on the data collation part. Thank you.
At my work, we produce power converters: put some arbitrary voltage into this chip, and it produces a precise, fixed voltage. They're what turns a cellphone battery's power into what's needed by the display, backlight, processor, and transmitter, frinstance. The efficiency of a converter is what determines how long the battery lasts, and it's measured by how much power comes out compared to how much went in. We quantify this by supplying a range of input voltages, and for each one, varying the output current -- the demand. Since we can measure the input current, and we know the output voltage, the output voltage * current, divided by the input voltage * current, is the efficiency. From this we can derive a three-dimensional curve, a surface, showing the efficiency at each point within the operational voltage/current limits. Doing a thousand of these measurements and writing the value for each point, takes a couple of days to produce a reasonably high-resolution curve. Which we had an apps engineer doing, by hand, to a predetermined accuracy. What I wrote does the same thing in two hours, using a stack of power supplies, power sinks, and multimeters, all hooked up by GPIB, but there's a sticking point.
Electricity has two facets: amperage, which is basically how many electrons are flowing, and voltage, which is a measure of each electron's energy. Amps aren't lost: you don't have electrons getting stuck in corners and not coming back out. Voltage, however, IS lost. That's the whole point of voltage, essentially: when you plug something in, you're changing the volts into work and heat, and returning the used electrons, the amps, to the power company to be recycled. So when I want to measure efficiency and I put a certain voltage into a power converter, some of that voltage is lost in the wires themselves, heating them up. I tell the power supply to produce 5 volts, and it does, but the load at the other end of the wires may only receive 4.8 volts. That doesn't sound like such a big deal, but it's 4%, and when your system is 92% efficient and someone else's is 96% efficient, guess whose system gets purchased?
To account for this, I could either use short, fat wires from the power supply -- like jumper cables, short fat wires lose less voltage -- or I can measure the voltage right at the converter, and know what it's actually using. Even better, I can build a closed-loop feedback system, where I tell the power supply to produce 5 volts, measure what's actually being delivered, then tell the power supply to raise its voltage until I'm getting what I originally wanted. Then I don't care about wires. So that's what I did, and to make it even neater I wrote a software controller that optimizes the loop response -- it closes in on what I want like an informational homing torpedo. It's neat to watch, especially when I consider how long it takes to do this by hand. Especially when I've done it by hand, for two days.
You might be interested in knowing that MS Excel, despite its claims, only seems to have one good way to do graphic display of 3-D information: a pivot table from which a surface chart takes its data. It took me forever to figure that out because it doesn't seem to be listed anywhere in the help files. But if I set up the output from the measurement system as tab-delimited outputs of the form:
\t\tOscars \tRazzies \tScuzzies\n
hanks \t5 \t3 \t2\n
roberts \t7 \t3 \t4\n
cruise \t2 \t5 \t9\n
excel chews it up and makes a lovely graph, from which we can see where the converter's poles and nodes are, and get a measurement of capacitor quality and loss across the diode that's 1/3 of a good switching power supply (and its major source of efficiency loss at low input voltages.)
For the record, it's written in MatLab but I'm moving it over to a C script with plotting in GNUplot.
I'm going with Mistshadow2k4 on this: you've clearly never actually worked. My last job, we didn't have the internet, we didn't have TV's, we didn't get potty breaks except federally mandated 15 minute breaks in the morning and evening. I was a tech so I actually had access to a phone; the assembly people had one hour per ten hour shift where they were not required to be in their seats working. (thirty minutes for lunch, timed, with punchcards; two fifteen minute breaks, timed, with punchcards.) Talking was *strongly* discouraged. Stuff was coming down the line at the same rate the entire shift unless something broke, and if you fell behind, everyone knew who was at fault. We worked 10 hours a day, six days a week, and some Sundays, and if you didn't show up, even if you were sick and called in, you were fired.
It sucked more than I can say. Everyone there hated it. But boy were we productive.
For neutral or negative stability aircraft, fly-by-wire is necessary, and even for commercial aircraft it's a big help. (I've gotten a little time in a very big airplane that predates servo/hydraulic systems, and let me tell you, it's no joke. Commercial pilots in the '40's must've been pretty muscular.)
The difference is: that's something close to a linear function, and can be modelled and turned into a few lines of software, in the case of a transport aircraft, or some DSP code for a negative-stability aircraft. It can be tested over the entire range of possible inputs and outputs: it can be entirely quantified. That's not the case with autopilots and collision avoidance systems: the feedback/feedforward and even just the number of variables completely exceeds any hope of exhaustive testing. That means, in order for it to work, it has to have sanity, a sense of what's right and wrong, and as of yet we haven't managed to write code that does that reliably.
>I've often sort of wondered if Roy knew Deckard was a replicant.
That's been my assumption. Roy and Rachel both considered Deckard to be at least some type of equal.
(by the way, the 'if Deckard's a replicant, why did he get the crap beat out of him' question could also be asked of Rachel during the, well, date rape scene, for lack of a better way of dealing with that unsettling bit. I've assumed in the past that since Deckard doesn't know he's a replicant but does know she is, that's some weird sort of assertion of himself -- since he can't bring himself to kill her, he rapes her instead, as an assertion of power.)
So, in the book, there were almost no actual animals in the world: sheep were unbelievably valuable. I've often wondered if, in the movie, most all the humans were actually replicants, if humans were as rare as all the other animals and it was only Tyrell and a few others, who were repopulating the whole world with replicants, and nobody knew.
Given that today's front-page-top-center-headline is "Incidents Prompt New Scrutiny Of Airplane Software Glitches" and the accompanying article discusses a number of autopilot problems that have led to uncontrolled/out-of-control situtions on commercial jets during flight.
There are rules for avoiding collisions. In-flight collisions among commercial traffic are unbelievably rare in the First World because pilots don't generally BSOD or have their sensors start giving them false information. (To be more precise, they're trained to understand the quality of information their instruments are giving them, and decide when to stop trusting that information.)
Software can clearly fly planes, and fly them safely. It also clearly isn't managing to do so yet and until we can write software that's better than two pilots we shouldn't be putting it in aircraft.
And I meant to mention that drug-runners thought they'd scored gold when the first all-composite homebuilts, like Burt Rutan's (of SpaceShipOne fame) EZ and Long-EZ, started hitting the used aircraft market. Composites! Invisible to radar! Except the engines, all covered in sharp little edges and corners, stood out like beacons for radar, better (according to a radar tech friend of mine) than a smoothly-covered metal aircraft. Plus the homebuilts often had less cargo space so they didn't do very well for high-volume contraband. Ooops.
Raytheon developed a radar system that used reflections from commercial TV and radio transmissions to track objects. It worked pretty well but the US government wasn't interested in funding it... that is until China developed something similar. Both can give reasonably good positioning -- good enough for a missile to launch (after which point, presumably, it'll be doing its own tracking) without exposing the missile launcher to pre-launch suppression fire. Several newer systems have used GPS signals to do the same thing, which is really difficult, given how weak the signals are, but you can always rely on at least some GPS signals, while commercial TV/radio might not be operational.
Many of the stealth planes use facets to make big specular reflections of radar signals, on the theory that you're much less likely to pick up a huge narrow bounce than a much lower-level, omnidirectional bounce. This is used in both the B2 and the F117, but both also use paint that contains radar-absorptive paint, as I recall.
One of the early anti-radar setups ran into an interesting problem: the signal they got from the mounting hardware completely overwhelmed the signal they got from the stealth airframe so they couldn't easily measure improvements. I've read that it is precisely this attention to detail -- edges, screw heads (and the slots for screwdrivers) and the like, that show up on radar when the bulk body has been disguised.
Early radar operators in England kept detecting what they called 'angels' and after the war they realized they were picking up flocks of birds. In the '70's the local air traffic control center could easily pick up and distinguish between different truck sizes on the interstate highway 20 miles to their east, which was a problem for distinguishing low-flying aircraft in the small (non-ATC, so not THAT much of a problem) airports beside and near the interstate.
My girlfriend bought copies of Tomb Raider I and II and Gia not because they were good movies -- they're complete and utter crap -- but because each one had a scene or two that showed off some of Angelina Jolie's, uh, assets. My gf bought them all at a used store, not caring that one was scratched ("as long as it's not scratched during the money shot") and says they're utter crap, would never buy them for full price, blah blah blah.
The point being: just because something is utter, mindless tripe doesn't mean that a bit of it might not have value to someone. However, if you think something is mindless crap, it's really hard to convince yourself to pay full price for it.
I think one of the reasons ITunes is so popular is it allows you to winnow. I like MC 900 Foot Jesus, but there's only one song of theirs I'd actually pay for. As weird a thought as this may seem, it's quite possible that people might buy scenes from movies, where if they can only get the whole movie they can't bring themselves to pay for it, so they acquire it. Look at Windows: no way in hell I could convince myself to pay retail price, but I have a copy so I can run Photoshop.
Note that I'm not saying it's right, or that it's any justification whatsoever for copyright infringement. It's not. All I'm talking about here is the psychology of the situation, and why people might have stuff they, themselves, consider worthless, in violation of copyright.
We gritted our teeth and slid them apart. They were trashed already, but that process didn't do them any good whatsoever. If I *had* to get them apart, without damage, I think I'd try putting them under a vacuum with one attached to something and the other hanging; when the water between them, or its dissolved gases, starts to boil they'd come right apart without damaging them, and gravity would keep them separate.
(from the article I linked: "Contact mechanical models suggest that self-cleaning occurs by an energetic disequilibrium between the adhesive forces attracting a dirt particle to the substrate and those attracting the same particle to one or more spatulae. We propose that the property of self-cleaning is intrinsic to the setal nanostructure and therefore should be replicable in synthetic adhesive materials in the future.")
As Anonymous Coward said, even the comparatively rough gauge blocks used in machining setup can be wrung together, which is traditionally done by touching one of them to your inner (not-so-hairy) arm to get some perspiration or oil, then placed against the other and pressed/turned. They *stick* like magnets. You see the same thing with wet microscope slides. All you need is enough flatness to let the applied water form a capillary film between the surfaces, so increasing the flatness quality reduces the amount of water needed until at some point, like with the gravity detector's mirrors, just the water layer formed by being exposed to humid air is sufficient to form a pretty impressively strong bond. I've worked with laser optics that are flat to within a half-wavelength of visible light, and they really like being together.