Don't forget Heinlein's book Waldo Inc., where wireless power transmission was used to power everything (including flying cars). RAH also covered the inevitable health effects of living in a world saturated by electromagnetic radiation.
As far as projects go, NASA is developing solar power satellites using microwave power transmission. There was a slashdot article a while back on this, but I'm too lazy to dig up the url (surely you can find it yourself)
Try "It can't happen here", Sinclair Lewis, 1935. Great book which blows 1984 out of the water imho- describing the growth and establishment of fascism in the good ol' US of A. Instead of showing the instigators as malicious, evil masterminds, Lewis portrays the leaders as incompetent bumbling idiots (the similarities between the head Corporatist(1) and Duh-bya are remarkable). Almost painfully realistic, with real headlines from the 30's thrown in for effect, this book gave me nightmares for weeks.
ICHH comes complete with machine gun toting boy scouts beating innocent bystanders, Americans fleeing to Canada, and pointless, bloody wars fought to keep political scandal out of newspapers. The single most important idea to be taken from it is just how fast these things can happen; once an idea becomes fashionable, and the guys with guns get the power to use them, the game is over.
Rev Neh
(1) Corporatist by the classical definition, not that of slashbot/katzian fame
First off, let me say this: I was wrong about the whole "SGI used parallel EISA slots" thing. The cards took up 3 slots, but only because they were 3 cards stacked together. They attached to the computer through a single GIO connector. Regardless, I think it would be fun to play with the idea a bit more.
That would be just while using it with memory rich graghics cards.
I would assume that if someone was going to this degree of effort to build the ultimate framecranking game engine, they would put enough memory on it for all the bottlenecks to be somewhere else. Maybe I am wrong, but memory is pretty cheap.
Adding complexity==lower yields==higher per unit prices. Not to mention that it would add complexity to the BIOS code.
Undoubtedly. But is this really the issue? SGI designs their own architecture from scratch with every computer they build. If you are going to do that anyway, why not really do it? I'm thinking possibilities here, not necessarily looking for the cheapest solution. I have that luxury, since I've already admitted ignorance in this area; I'm trying merely to think outside the box a bit.
As far as implementing something like this on the desktop: What would make it impossible? What if you used one AGP slot and 1-2 PCI slots? That wouldn't affect the bios or the chipset at all. As far as the motherboard is concerned it would be just like adding a Voodoo2 to a 2d card. SGI had direct pin connections between their Max Impact cards, allowing them to talk to each other without burning cpu power/bandwidth. Our hypothetical heroic graphics card company could do the same. Make the system expandable in sets of four gfx processors, limited only by space in the box and by power/cooling requirements.
As far as power requirements go, I think the 3DFX solution here is terrible. If you are going to need 400W, why not plug in a standard hard drive power connector to the card? SGI used a seperate power connector directly from the PS on their High Impact series. A 400W PS costs about $100, while a voodoo 6000+external PS is going to cost $600. Once you start talking about that kind of money, a slight increase in cost is academic.
Oh well. Enough daydreaming. Time to drink a Sundrop and try to get some work done.
low end I2's had 100, 150, 200 or 250 mhz R4400's while high end I2's had 175 or 195 R10000's. Some also has 150 or 180 mhz R5000's. There was also a R8000 variant which used a 75-80 mhz chip. Sgi hrware faq is here.
My experience with I2's shows that an R4400 is about comperable to 1.25 mhz on a Pentium 2, while an R8k or R10k is about 2-3 mhz P2. I've never used an R5k; they seem to be aimed at the graphics types, while the 44k, 8k, and 10k were aimed at the numerical simulation folks. Your results may vary, of course; Spec 95 CINT results for an R10k 195 were very disappointing- comparable to a PII 266. Some similar POV-ray render speed benchmarks can be found here as well.
Anybody remember how video cards worked on Indigo II's? It's been awhile since I opened one up but IIRC the motherboard had a riser card with EISA slots in back and some kind of other slot in front. SGI used parallel EISA slots to overcome the speed limitations of EISA. The entry level graphics card was 18"x4" and filled one slot, while the "Extreme" card filled 3 slots on the board... when the "Impact" series came out they even had to boost the power supply and run a direct power cable from the ps to the boards. Once again, the Max Impact took 3 slots, while the High Impact took and the Solid Impact one.
Here's a picture of an Extreme card. This is not my auction, btw... I just didn't feel right about deep linking to the picture and it's the only one I could find.
As a matter of abstract, ignorant speculation: how hard would it be to implement several modern AGP slots on a motherboard and plug in multiple cards either SLI fashion or SGI "extreme gfx/max impact" fashion? Or even better, would it be possible to build a video card which filled one AGP slot and had a second subcard which fit in one or two PCI slots? It seems like a relatively elegant solution to an ugly problem. At least, it seems like a really cool project, and better than using an external power source.
That's really interesting. I recently blew up my old K6-3 ss7 MB (literally blew up, with smoke and stuff) by doing something really dumb with a soldering iron, and decided to replace it with a 750 T-bird. The tbird, clocked to 803 at -.5%voltage and only cooled by a single stock fan, stays cool enough to touch the heat sink even after playing q3 for hours. The k6 and the p1-200 that I had before both ran way too hot to do this even before overclocking.
Anecdotal evidence, of course, but it is what is happening to me. I guess I got lucky.
Rev Neh
Re:The sleestack come before us... Re:Great news
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TigerCloning
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· Score: 2
If you're a human and you hunt some game, you win, but if you kill just about everything, well...
Then you had better be a good farmer.
So, the question is--- is the "natural Darwinistic act" of an intelligent species evolving and destroying things before going extinct something that happens every several million years? If so, no problem!
There was a science fiction story a while back (~1975?) about time travelers who went back to try to determine what killed off the dinosaurs... what they found was small raptor-sized super-intelligent creatures with hunting rifles and nuclear weapons. The images fueled a lot of nightmares when I was 12.
First the sleestack, next us.
Similar. Check out HP Lovecraft's The Nameless City for yet another description of lizard-men whom evolution dealt with harshly... in TNC, they seem to be returning for a second act. Regardless, it seems to be a common theme in literature: the most terrifying creature is one that thinks, and the second most terrifying creature is one that is almost human. Combine the two abstractions and you get monsters like the lizard people/flying monkeys/slant-eyed hairless aliens depicted in everything from Oz to V to the X-files.
Rev Neh
Re:The human conception of morality does not matte
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TigerCloning
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· Score: 2
IMHO, this is really where the alleged morality in religon breaks down
Read Heinlein's Job (aptly titled) for an interesting, witty exposition of the same concept you're expounding on here. RAH's deus ex machina ending is one of the best I've ever seen. Hint: he answers the question "who judges God?".
But didn't He implicitly grant authorization when he sold--
NO CARRIER
You've gotta be careful when dealing with irrational deities. This reminds me of the wonderful lovecraft fanfic quote: "What a useless scroll... all it says is Hastur! Hastur! Hast- aaaaaargh!"
My money's on picture #13 from the first set. The cloud tendrils have such a, err, cthulhic look. Although Oakie is kind of cute too- perfect form, good color, well balanced; at least a 9.3 (from this conservative judge).
Unfortunately, because of the boneheaded way American law works, once a law is passed, you pretty well can't get rid of it unless you can prove that it's "unconstitutional", and likewise, you can't create laws that conflict with the constitutional dogma
It's pretty easy to get rid of a law once it's been passed. You just bury a rider 500 lines deep in a budget bill that says "The DMCA is hereby repealed", get both houses to sign off on it, and start watching movies on your platform of choice.
IANAL BIRA LOS (I am not a lawyer (but I read a lot of Slashdot)).
The ARGHSoA is awesome... funny as hell, especially if you've seen a lot of objectivist antics first hand. The timeline is lame though; it reads like something the Unibomber would have made for his 5th grade teacher. I just couldn't find anything funny about it (and I tried hard). Maybe you could pont out the intricacies I missed?
Reading Jamie's link, I can't help ROFLMAO. Only in Washington would a man be able to introduce a bill with the designation "S.97" that goes by the Short Title of "Children's Internet Protection Act".*
I trust McCain et. al in exactly the same way I trust a hungry wild dog: I won't shoot him as long as he's keeping the rats away, but when he starts offering to babysit I get uncomfortable. There are some things I just don't need his help with.
Although I like the idea of being able to sue people who misuse my personal information, I wouldn't be surprised if the title of this bill is misleading. McCain is good enough to get away with fooling most of the people most of the time. For instance, the much publicized Bipartisan Campaign Reform Act, which the general populace accepted as panacea, does absolutely nothing to reform campaign finance except allow larger PAC contributions and allow employees to opt out of labor union contributions they don't agree with. And does anyone -really- believe children are protected by censorship?
Calling this bill a Privacy Bill is falling into the exact same trap. It will not create any true standards of privacy. Instead, it will create the illusion of privacy, where non-US web sites can still use your information however they want and US web sites need only say "We sell your info to the highest bidder(s)" in blinking size 3 Tacoma font at the bottom of the page. Beneath the TrustE logo.
You don't have to worry about me, Andrew. At least not for a while yet... A man must be quite bored to institute a full scale militant isolationist theocracy in a constitutional republic, and slashdot keeps me busy enough that I don't have time to bother.
Ralph Nader, however, should have you terrified. He's a bored man with a cause.
Dr. Hoyt, from Tethers Unlimited, presented several papers and chaired a general session on this at this years AIAA Joint Propulsion Conference in Huntsville last week. If you are really interested in this stuff you can order them from AIAA ($11.95 each!) or get them from a tech library near you:
AIAA-2000-3615 Design and Simulation of Tether Facilities for the HASTOL Architecture (Hoyt)
AIAA-2000-3866 Design and Sim of a Tether Boost Facility for GEO, Lunar, and Mars Transport (Hoyt, Grant, and Bangham)
AIAA-2000-3865 Computation of Current to a Moving Bare Tether, (Onishi & Martinez, MIT, and Cooke, AFRL)
AIAA-2000-3870 Future Application of Electrodynamic Space Tethers For Propulsion (Santangelo, Michigan Technic and Johnson, Nasa Marshall)
I apologize for not being able to link to the specific papers or give much additional information, since this panel ran at the same time as one I was more interested in and the papers are copyrighted by AIAA. The fact that technical publications are generally not available upon demand except in bulk or by federal express is increasingly irritating to me, since 1) they are available in.pdf format on CD-ROM at the conference anyway, and 2) many distribution systems exist which would allow the organizations to distribute them electronically and still get paid. Please complain (nicely) to Webmaster@aiaa.org about this, since my lonely voice is probably not loud enough to cause action.
The airplanes of today are the airplanes of the 1970's, in many cases.
I don't want to be excessively argumentative, and I agree with your comments re. cars, especially the individualism remark. However, I guarantee you that there are more automobiles on the highways today that were built in the late 70's/early 80's than there are engines in aircraft built in the same time period. Especially in atlanta- I've been forced to navigate Atlanta traffic during rush hour (3 pm to 8 pm!) many times, and I am amazed at how many ancient cars there are billowing smoke and noxious fumes. What is I-75, seven or eight lanes? Bumper to bumper full of boatmobiles with 20 year old V-8 engines running completely off-design, at their least efficient performance point. I literally cannot roll down my windows. I'm sure a lot of cities have similar traffic problems, but imho Atlanta is the worst.
Aircraft airframe design is very well understood, and has been for many years. This is why airlines today still use aircraft that were designed in 1970, with a few minor modifications. It's pretty tough to improve on a vehicle already optimized for a given flight regime. However, turbine engine technology has advanced a tremendous amount in the intervening years, and an airline can save big money with even a fraction of a percent increase in fuel efficiency or power. Combine this with the fact that engines are designed to be replaced every few years (more precisely, every thousand hours or so of flight time) and are required to undergo periodic overhauls for safety reasons and you start to see why very few 30 year old engines are still in the air.
I disagree. Voting from my computer means that when I see a list of names, I can do at least rudimentary research into who I am voting for at the time I vote. Most people do this for president and governer level offices anyway, but can you honestly say you have any way of differentiating between the two candidates for Second Assistant Dogcatcher? I generally do not have the time it takes to even find out who is running for most local offices before i get into the booth.
In the time it takes me to drive into town and vote, I can sit at my desk and look up who I am voting for, see where they stand on issues I care about, and make a semi-informed choice. I want this.
Also, voting is not a social act- voting is a fiercely individual act. I vote for who I want to see in office, not who I think you want me to vote for. If voting were a social act we would all gather in the town square and vote by raising our hands in plain view of everyone else.
Yeah, my little blue Abbott/Doenhoff is prominently placed amongst the "good books I don't read much anymore" bookshelf. It's a bit dated, since most modern aero types design their own airfoils for a particular application, but it is pretty good for developing an undergraduate level understanding of the applicable theory. The tas section is great. Unfortunately TOWS doesn't really go into more advanced methods. If you are interested I highly recommend Belotserkovski's "theory" book, and especially Richard Eppler's "Airfoil Design" book. Eppler's is interesting because he was a (very) early champion of computational techniques in airfoil design, and his book contains snippets of Fortran code that does just that. Also, UIUC has an excellent database of airfoils designed by Eppler and Selig which I have used quite extensively in building model aircraft.
Anyway aeronautics is the science of designing an airplane or other flying machine, not the science of determining the effect of deforestation on the living environment of people in Atlanta. That is meteorology, and the scientists imo should have sought funding from 1)their university (GA tech) 2)private sources (i.e. Ralph Nader, the green party, etc.) or 3) government agencies designed to support meteorological research, such as the National Climate Prediction Center", the National Weather Service or the NDBC. I don't think that NASA had any right to spend my money on this survey. If this case is a typical of their "Mission to Planet Earth", then I think that there is a problem with the organization that needs to be fixed- because NASA isn't designed to fill this role. If they had no better use for the money, then it should not have been spent- regardless of the fact that this is anathema to bureaucrats everywhere.
How I screwed up NASA's acronym is beyond me. I think you are right though- I have the NASM on my mind since I was in DC last week (4th). FYI I don't recommend that particular experience. No matter how patriotic you are, stay the hell away from that city in the summertime, especially on a national holiday.
This may be a bad question to ask on Slashdot, but why did NASA, of all people, fund this research?
NASA stands for National Air and Space Administration. They were founded to explore the boundaries of Air and Space research- that is, develop technology to expand mankind's reach into space and areas of flight which pose significant technological difficulties to engineers in the aerospace industry. NASA is supposed to launch probes to explore the solar system, build research vehicles to expand our knowledge of unusual aerodynamic flight regimes, and develop technology for launch vehicles. NASA's charter is to accomplish experimental research that is too expensive for private industry to accomplish at this time.
I'm not saying that NASA is bad, or that the research done in this study was superfluous or redundant. I just think that a more appropriate source would have been the EPA, the University of Colorado, or Ralph Nader and his acolytes.
Since the engine's thrust is greater than the weight of the car, it's likely that, under full power, the J-85 could accelerate the car with a force greater than 1G.
What this also means is that the engine could, under the right conditions, accelerate your car straight up. For instance, if you put a large piece of water-cooled steel behind it at a 45 degree angle, you could achieve sustained uncontrolled flight without any aerodynamic lifting surfaces. Obviously it will be very difficult to achieve those conditions- most likely your engine is rated for 2200 lbf thrust at 500 miles per hour at 10,000 feet. You'll probably get a lot less than that at sea level, at chevette-speed.
To find out how fast your car can accelerate with this thing, you would just use Force = Mass*Gc*Acceleration. Force = 2200 lbf, Mass = 1600 lbm. You'd get about 1.25 G's acceleration out of the engine alone- 0-60 in about 2.2 seconds. That's cumulative with the car's engine as well, which means you can probably do it in under 2. Better have some heavy duty tires!
BTW, you're too late with the "world's first street drivable jet car". A friend of mine (who is flying F-15's now) mounted a home-made pulse detonation engine (PDE) to the hood of his 1981 voltswagon P.O.S. car back in college. He succeeded in doing little more than making a heck of a lot of noise and breaking his window- but he did make it work, getting positive thrust etc.
It sounds like your car could be much more interesting. Good luck...
Figures, I see a huge error immidiately after posting something I've proofread 15 times. ANyway T and D generally zero themselves out by acting through the cg, not the ac. Sorry...
Aerodynamics is my area of expertise, and Mr. Carmack has hit it right on the head. He even used the correct terminology. What aerodynamically unstable really means is that any perturbation in the flow will tend to propogate rather than be damped. It is possible for an unstable aircraft to fly, if it possesses a modern fly-by-wire system and has sufficient control authority to right itself once it has become perturbed; almost all modern fighter aircraft are designed slightly unstable. However, I don't think this vehicle will possess either.
Anyway I'm not sure where you get your number for velocity from- the only quote I saw for predicted velocity was 600 miles per hour, which is well below the speed of sound even at 100,000 feet. A velocity of 1.4 kps is roughly Mach 4.1 at sea level, or 4.25 at altitude.
At 600 mph, which seems like a very reasonable speed for this vehicle given the amount of thrust produced by its engines, there will be no shock waves. The only aerodynamic forces will be those produced by the lifting surfaces on the craft- the three large fins on the nose. There will also be drag components which act directly behind the aircraft and a thrust component which eminates from the engines (T and D generally zero themselves out by acting through the aerodynamic center). When you balance these forces and normalize them according to the length of the vehicle, you will come up with a location on the vehicle known as the aerodynamic center. If the aerodynamic center is behind the center of gravity, the aircraft is said to be statically stable and will therefore fly straight, righting itself after perturbations occur. This design is most likely statically unstable, because its aerodynamic center is (painfully obviously) well ahead of its center of gravity. Think about an arrow: it flies straight because it has a cg near the front and an ac near the rear.
At M=4, you are correct that breezes are orders of magnitude below the pressure differential caused by a strong shock structure. The static pressure behind a normal shock would be 18.5 atmospheres! However, this fact is largely irrelevant, since the shock structure won't -ever- be perfectly symmetric. An asymmetric shock structure will produce regions of differing static and dynamic pressure behind the shock. This will manifest itself as a powerful force applied approximately to the nose of the vehicle. The rocket will then begin to rotate about its center of gravity, and the pressure force will tend to increase as the rocket begins to rotate because the angle of attack increases the pressure difference (through various means). The only way to solve this is to move the ac back as far as possible, preferably by adding fins near the rear of the vehicle. It can also be done with thrust vectoring.
:endresult The end result at either mach number will be a spinning projectile which eventually tears itself apart due to the propellant chambers experiencing accelerative forces on non-loadbearing walls.
If by some miracle of engineering this does not occur, he would still (probably) not survive sustained flight at Mach 4 in this vehicle. The ballistic coefficient of the nose appears to be too low, which will cause a concentration of aerodynamic heating at the tip. I really can't tell for sure from the picture, but hypersonic vehicles are generally designed with blunt noses so that the wave detaches from the body, allowing the heat to dissipate. If it stays attached there will be a small region in which a layer of incredibly high entropy develops which will cut through steel like a knife through warm butter. For more details, search the web for pictures of what happened to the scramjet NASA tried to hang from an X-15 in the 60's.
FWIW a (statically stable!) titan IV experienced rotationally induced structural failure early in the program when an engine malfunctioned, causing the rocket to become unstable. It is an incredibly important concept that Walker seems to have completely overlooked.
Don't get me wrong; I hope this guy succeeds. I really, really do, partly because I admire his courage and tenacity and partly because it will provide an immeasurable benefit to space privatization advocates everywhere. Since I am an aero type, I stand to benefit tremendously from explosive growth in that sector of the economy. Unfortunately, he won't do it with this design, which makes it exceedingly frustrating-- because it really isn't that hard to design a rocket to do what he wants to do...
Rambus wasn't awarded the "804 patent" until 21 September 1999. So they didn't sit on it all that long before defending their rights.
In this case, the single point of failure rests with the USPTO- for taking 10 years to read a piece of paper and put a stamp on it. If they had done their job correctly, we would have been paying royalties to Rambus since 1990 or so. (Whether or not this is good or bad is left as an exercise for the student).
Thanks for that link- it is quite interesting. I had never seen RSR before, but will definitely use it in the future. Hopefully about 10,000 other people will see it and provide a large enough set of data points for its evaluation of sellers to be worth something...
Slashdot Mirror
Don't forget Heinlein's book Waldo Inc., where wireless power transmission was used to power everything (including flying cars). RAH also covered the inevitable health effects of living in a world saturated by electromagnetic radiation.
As far as projects go, NASA is developing solar power satellites using microwave power transmission. There was a slashdot article a while back on this, but I'm too lazy to dig up the url (surely you can find it yourself)
Neh
A machine with some form of intelligence would never get past the regulations. Who knows what their code will attempt to do!
You would just need a manual override. All battlebots have to have a means of rendering them harmless from a distance anyway, so this is a non-issue.
Rev Neh
Try "It can't happen here", Sinclair Lewis, 1935. Great book which blows 1984 out of the water imho- describing the growth and establishment of fascism in the good ol' US of A. Instead of showing the instigators as malicious, evil masterminds, Lewis portrays the leaders as incompetent bumbling idiots (the similarities between the head Corporatist(1) and Duh-bya are remarkable). Almost painfully realistic, with real headlines from the 30's thrown in for effect, this book gave me nightmares for weeks.
ICHH comes complete with machine gun toting boy scouts beating innocent bystanders, Americans fleeing to Canada, and pointless, bloody wars fought to keep political scandal out of newspapers. The single most important idea to be taken from it is just how fast these things can happen; once an idea becomes fashionable, and the guys with guns get the power to use them, the game is over.
Rev Neh
(1) Corporatist by the classical definition, not that of slashbot/katzian fame
First off, let me say this: I was wrong about the whole "SGI used parallel EISA slots" thing. The cards took up 3 slots, but only because they were 3 cards stacked together. They attached to the computer through a single GIO connector. Regardless, I think it would be fun to play with the idea a bit more.
That would be just while using it with memory rich graghics cards.
I would assume that if someone was going to this degree of effort to build the ultimate framecranking game engine, they would put enough memory on it for all the bottlenecks to be somewhere else. Maybe I am wrong, but memory is pretty cheap.
Adding complexity==lower yields==higher per unit prices. Not to mention that it would add complexity to the BIOS code.
Undoubtedly. But is this really the issue? SGI designs their own architecture from scratch with every computer they build. If you are going to do that anyway, why not really do it? I'm thinking possibilities here, not necessarily looking for the cheapest solution. I have that luxury, since I've already admitted ignorance in this area; I'm trying merely to think outside the box a bit.
As far as implementing something like this on the desktop: What would make it impossible? What if you used one AGP slot and 1-2 PCI slots? That wouldn't affect the bios or the chipset at all. As far as the motherboard is concerned it would be just like adding a Voodoo2 to a 2d card. SGI had direct pin connections between their Max Impact cards, allowing them to talk to each other without burning cpu power/bandwidth. Our hypothetical heroic graphics card company could do the same. Make the system expandable in sets of four gfx processors, limited only by space in the box and by power/cooling requirements.
As far as power requirements go, I think the 3DFX solution here is terrible. If you are going to need 400W, why not plug in a standard hard drive power connector to the card? SGI used a seperate power connector directly from the PS on their High Impact series. A 400W PS costs about $100, while a voodoo 6000+external PS is going to cost $600. Once you start talking about that kind of money, a slight increase in cost is academic.
Oh well. Enough daydreaming. Time to drink a Sundrop and try to get some work done.
Rev Neh
low end I2's had 100, 150, 200 or 250 mhz R4400's while high end I2's had 175 or 195 R10000's. Some also has 150 or 180 mhz R5000's. There was also a R8000 variant which used a 75-80 mhz chip. Sgi hrware faq is here.
My experience with I2's shows that an R4400 is about comperable to 1.25 mhz on a Pentium 2, while an R8k or R10k is about 2-3 mhz P2. I've never used an R5k; they seem to be aimed at the graphics types, while the 44k, 8k, and 10k were aimed at the numerical simulation folks. Your results may vary, of course; Spec 95 CINT results for an R10k 195 were very disappointing- comparable to a PII 266. Some similar POV-ray render speed benchmarks can be found here as well.
Rev Neh
Anybody remember how video cards worked on Indigo II's? It's been awhile since I opened one up but IIRC the motherboard had a riser card with EISA slots in back and some kind of other slot in front. SGI used parallel EISA slots to overcome the speed limitations of EISA. The entry level graphics card was 18"x4" and filled one slot, while the "Extreme" card filled 3 slots on the board... when the "Impact" series came out they even had to boost the power supply and run a direct power cable from the ps to the boards. Once again, the Max Impact took 3 slots, while the High Impact took and the Solid Impact one.
Here's a picture of an Extreme card. This is not my auction, btw... I just didn't feel right about deep linking to the picture and it's the only one I could find.
As a matter of abstract, ignorant speculation: how hard would it be to implement several modern AGP slots on a motherboard and plug in multiple cards either SLI fashion or SGI "extreme gfx/max impact" fashion? Or even better, would it be possible to build a video card which filled one AGP slot and had a second subcard which fit in one or two PCI slots? It seems like a relatively elegant solution to an ugly problem. At least, it seems like a really cool project, and better than using an external power source.
Rev Neh
I find the Law of Fives to be more and more manifest the harder I look. For instance, using the current 6 digit userid system,
0+6+9+0+6+9 = 30;
30/6 = 5.
Methinks the goddess had a hand in this.
Rev Neh
That's really interesting. I recently blew up my old K6-3 ss7 MB (literally blew up, with smoke and stuff) by doing something really dumb with a soldering iron, and decided to replace it with a 750 T-bird. The tbird, clocked to 803 at -.5%voltage and only cooled by a single stock fan, stays cool enough to touch the heat sink even after playing q3 for hours. The k6 and the p1-200 that I had before both ran way too hot to do this even before overclocking.
Anecdotal evidence, of course, but it is what is happening to me. I guess I got lucky.
Rev Neh
If you're a human and you hunt some game, you win, but if you kill just about everything, well...
Then you had better be a good farmer.
So, the question is--- is the "natural Darwinistic act" of an intelligent species evolving and destroying things before going extinct something that happens every several million years? If so, no problem!
There was a science fiction story a while back (~1975?) about time travelers who went back to try to determine what killed off the dinosaurs... what they found was small raptor-sized super-intelligent creatures with hunting rifles and nuclear weapons. The images fueled a lot of nightmares when I was 12.
First the sleestack, next us.
Similar. Check out HP Lovecraft's The Nameless City for yet another description of lizard-men whom evolution dealt with harshly... in TNC, they seem to be returning for a second act. Regardless, it seems to be a common theme in literature: the most terrifying creature is one that thinks, and the second most terrifying creature is one that is almost human. Combine the two abstractions and you get monsters like the lizard people/flying monkeys/slant-eyed hairless aliens depicted in everything from Oz to V to the X-files.
Rev Neh
IMHO, this is really where the alleged morality in religon breaks down
Read Heinlein's Job (aptly titled) for an interesting, witty exposition of the same concept you're expounding on here. RAH's deus ex machina ending is one of the best I've ever seen. Hint: he answers the question "who judges God?".
But didn't He implicitly grant authorization when he sold--
NO CARRIER
You've gotta be careful when dealing with irrational deities. This reminds me of the wonderful lovecraft fanfic quote: "What a useless scroll... all it says is Hastur! Hastur! Hast- aaaaaargh!"
Can't remember where I saw that, unfortunately...
Rev Neh
I agree. Check out this page and this page for some cool pics. Cool videos here.
My money's on picture #13 from the first set. The cloud tendrils have such a, err, cthulhic look. Although Oakie is kind of cute too- perfect form, good color, well balanced; at least a 9.3 (from this conservative judge).
Rev Neh
Unfortunately, because of the boneheaded way American law works, once a law is passed, you pretty well can't get rid of it unless you can prove that it's "unconstitutional", and likewise, you can't create laws that conflict with the constitutional dogma
It's pretty easy to get rid of a law once it's been passed. You just bury a rider 500 lines deep in a budget bill that says "The DMCA is hereby repealed", get both houses to sign off on it, and start watching movies on your platform of choice.
IANAL BIRA LOS (I am not a lawyer (but I read a lot of Slashdot)).
The ARGHSoA is awesome... funny as hell, especially if you've seen a lot of objectivist antics first hand. The timeline is lame though; it reads like something the Unibomber would have made for his 5th grade teacher. I just couldn't find anything funny about it (and I tried hard). Maybe you could pont out the intricacies I missed?
Reading Jamie's link, I can't help ROFLMAO. Only in Washington would a man be able to introduce a bill with the designation "S.97" that goes by the Short Title of "Children's Internet Protection Act".*
I trust McCain et. al in exactly the same way I trust a hungry wild dog: I won't shoot him as long as he's keeping the rats away, but when he starts offering to babysit I get uncomfortable. There are some things I just don't need his help with.
Although I like the idea of being able to sue people who misuse my personal information, I wouldn't be surprised if the title of this bill is misleading. McCain is good enough to get away with fooling most of the people most of the time. For instance, the much publicized Bipartisan Campaign Reform Act, which the general populace accepted as panacea, does absolutely nothing to reform campaign finance except allow larger PAC contributions and allow employees to opt out of labor union contributions they don't agree with. And does anyone -really- believe children are protected by censorship?
Calling this bill a Privacy Bill is falling into the exact same trap. It will not create any true standards of privacy. Instead, it will create the illusion of privacy, where non-US web sites can still use your information however they want and US web sites need only say "We sell your info to the highest bidder(s)" in blinking size 3 Tacoma font at the bottom of the page. Beneath the TrustE logo.
Rev Neh
*Yes, I know the real "long" titleof S.97.
You don't have to worry about me, Andrew. At least not for a while yet... A man must be quite bored to institute a full scale militant isolationist theocracy in a constitutional republic, and slashdot keeps me busy enough that I don't have time to bother.
Ralph Nader, however, should have you terrified. He's a bored man with a cause.
Rev Neh
AIAA-2000-3615 Design and Simulation of Tether Facilities for the HASTOL Architecture (Hoyt)
AIAA-2000-3866 Design and Sim of a Tether Boost Facility for GEO, Lunar, and Mars Transport (Hoyt, Grant, and Bangham)
AIAA-2000-3865 Computation of Current to a Moving Bare Tether, (Onishi & Martinez, MIT, and Cooke, AFRL)
AIAA-2000-3870 Future Application of Electrodynamic Space Tethers For Propulsion (Santangelo, Michigan Technic and Johnson, Nasa Marshall )
.pdf format on CD-ROM at the conference anyway, and 2) many distribution systems exist which would allow the organizations to distribute them electronically and still get paid. Please complain (nicely) to Webmaster@aiaa.org about this, since my lonely voice is probably not loud enough to cause action.
I apologize for not being able to link to the specific papers or give much additional information, since this panel ran at the same time as one I was more interested in and the papers are copyrighted by AIAA. The fact that technical publications are generally not available upon demand except in bulk or by federal express is increasingly irritating to me, since 1) they are available in
Rev. Neh
propulsion geek
The airplanes of today are the airplanes of the 1970's, in many cases.
I don't want to be excessively argumentative, and I agree with your comments re. cars, especially the individualism remark. However, I guarantee you that there are more automobiles on the highways today that were built in the late 70's/early 80's than there are engines in aircraft built in the same time period. Especially in atlanta- I've been forced to navigate Atlanta traffic during rush hour (3 pm to 8 pm!) many times, and I am amazed at how many ancient cars there are billowing smoke and noxious fumes. What is I-75, seven or eight lanes? Bumper to bumper full of boatmobiles with 20 year old V-8 engines running completely off-design, at their least efficient performance point. I literally cannot roll down my windows. I'm sure a lot of cities have similar traffic problems, but imho Atlanta is the worst.
Aircraft airframe design is very well understood, and has been for many years. This is why airlines today still use aircraft that were designed in 1970, with a few minor modifications. It's pretty tough to improve on a vehicle already optimized for a given flight regime. However, turbine engine technology has advanced a tremendous amount in the intervening years, and an airline can save big money with even a fraction of a percent increase in fuel efficiency or power. Combine this with the fact that engines are designed to be replaced every few years (more precisely, every thousand hours or so of flight time) and are required to undergo periodic overhauls for safety reasons and you start to see why very few 30 year old engines are still in the air.
Rev Neh
I disagree. Voting from my computer means that when I see a list of names, I can do at least rudimentary research into who I am voting for at the time I vote. Most people do this for president and governer level offices anyway, but can you honestly say you have any way of differentiating between the two candidates for Second Assistant Dogcatcher? I generally do not have the time it takes to even find out who is running for most local offices before i get into the booth.
In the time it takes me to drive into town and vote, I can sit at my desk and look up who I am voting for, see where they stand on issues I care about, and make a semi-informed choice. I want this.
Also, voting is not a social act- voting is a fiercely individual act. I vote for who I want to see in office, not who I think you want me to vote for. If voting were a social act we would all gather in the town square and vote by raising our hands in plain view of everyone else.
Rev Neh
Yeah, my little blue Abbott/Doenhoff is prominently placed amongst the "good books I don't read much anymore" bookshelf. It's a bit dated, since most modern aero types design their own airfoils for a particular application, but it is pretty good for developing an undergraduate level understanding of the applicable theory. The tas section is great. Unfortunately TOWS doesn't really go into more advanced methods. If you are interested I highly recommend Belotserkovski's "theory" book, and especially Richard Eppler's "Airfoil Design" book. Eppler's is interesting because he was a (very) early champion of computational techniques in airfoil design, and his book contains snippets of Fortran code that does just that. Also, UIUC has an excellent database of airfoils designed by Eppler and Selig which I have used quite extensively in building model aircraft.
Anyway aeronautics is the science of designing an airplane or other flying machine, not the science of determining the effect of deforestation on the living environment of people in Atlanta. That is meteorology, and the scientists imo should have sought funding from 1)their university (GA tech) 2)private sources (i.e. Ralph Nader, the green party, etc.) or 3) government agencies designed to support meteorological research, such as the National Climate Prediction Center", the National Weather Service or the NDBC. I don't think that NASA had any right to spend my money on this survey. If this case is a typical of their "Mission to Planet Earth", then I think that there is a problem with the organization that needs to be fixed- because NASA isn't designed to fill this role. If they had no better use for the money, then it should not have been spent- regardless of the fact that this is anathema to bureaucrats everywhere.
How I screwed up NASA's acronym is beyond me. I think you are right though- I have the NASM on my mind since I was in DC last week (4th). FYI I don't recommend that particular experience. No matter how patriotic you are, stay the hell away from that city in the summertime, especially on a national holiday.
Rev Neh
This may be a bad question to ask on Slashdot, but why did NASA, of all people, fund this research?
NASA stands for National Air and Space Administration. They were founded to explore the boundaries of Air and Space research- that is, develop technology to expand mankind's reach into space and areas of flight which pose significant technological difficulties to engineers in the aerospace industry. NASA is supposed to launch probes to explore the solar system, build research vehicles to expand our knowledge of unusual aerodynamic flight regimes, and develop technology for launch vehicles. NASA's charter is to accomplish experimental research that is too expensive for private industry to accomplish at this time.
I'm not saying that NASA is bad, or that the research done in this study was superfluous or redundant. I just think that a more appropriate source would have been the EPA, the University of Colorado, or Ralph Nader and his acolytes.
Can anyone answer this?
Rev Neh
Since the engine's thrust is greater than the weight of the car, it's likely that, under full power, the J-85 could accelerate the car with a force greater than 1G.
What this also means is that the engine could, under the right conditions, accelerate your car straight up. For instance, if you put a large piece of water-cooled steel behind it at a 45 degree angle, you could achieve sustained uncontrolled flight without any aerodynamic lifting surfaces. Obviously it will be very difficult to achieve those conditions- most likely your engine is rated for 2200 lbf thrust at 500 miles per hour at 10,000 feet. You'll probably get a lot less than that at sea level, at chevette-speed.
To find out how fast your car can accelerate with this thing, you would just use Force = Mass*Gc*Acceleration. Force = 2200 lbf, Mass = 1600 lbm. You'd get about 1.25 G's acceleration out of the engine alone- 0-60 in about 2.2 seconds. That's cumulative with the car's engine as well, which means you can probably do it in under 2. Better have some heavy duty tires!
BTW, you're too late with the "world's first street drivable jet car". A friend of mine (who is flying F-15's now) mounted a home-made pulse detonation engine (PDE) to the hood of his 1981 voltswagon P.O.S. car back in college. He succeeded in doing little more than making a heck of a lot of noise and breaking his window- but he did make it work, getting positive thrust etc.
It sounds like your car could be much more interesting. Good luck...
Rev Neh
Figures, I see a huge error immidiately after posting something I've proofread 15 times. ANyway T and D generally zero themselves out by acting through the cg, not the ac. Sorry...
Rev Neh
Aerodynamics is my area of expertise, and Mr. Carmack has hit it right on the head. He even used the correct terminology. What aerodynamically unstable really means is that any perturbation in the flow will tend to propogate rather than be damped. It is possible for an unstable aircraft to fly, if it possesses a modern fly-by-wire system and has sufficient control authority to right itself once it has become perturbed; almost all modern fighter aircraft are designed slightly unstable. However, I don't think this vehicle will possess either.
Anyway I'm not sure where you get your number for velocity from- the only quote I saw for predicted velocity was 600 miles per hour, which is well below the speed of sound even at 100,000 feet. A velocity of 1.4 kps is roughly Mach 4.1 at sea level, or 4.25 at altitude.
At 600 mph, which seems like a very reasonable speed for this vehicle given the amount of thrust produced by its engines, there will be no shock waves. The only aerodynamic forces will be those produced by the lifting surfaces on the craft- the three large fins on the nose. There will also be drag components which act directly behind the aircraft and a thrust component which eminates from the engines (T and D generally zero themselves out by acting through the aerodynamic center). When you balance these forces and normalize them according to the length of the vehicle, you will come up with a location on the vehicle known as the aerodynamic center. If the aerodynamic center is behind the center of gravity, the aircraft is said to be statically stable and will therefore fly straight, righting itself after perturbations occur. This design is most likely statically unstable, because its aerodynamic center is (painfully obviously) well ahead of its center of gravity. Think about an arrow: it flies straight because it has a cg near the front and an ac near the rear.
At M=4, you are correct that breezes are orders of magnitude below the pressure differential caused by a strong shock structure. The static pressure behind a normal shock would be 18.5 atmospheres! However, this fact is largely irrelevant, since the shock structure won't -ever- be perfectly symmetric. An asymmetric shock structure will produce regions of differing static and dynamic pressure behind the shock. This will manifest itself as a powerful force applied approximately to the nose of the vehicle. The rocket will then begin to rotate about its center of gravity, and the pressure force will tend to increase as the rocket begins to rotate because the angle of attack increases the pressure difference (through various means). The only way to solve this is to move the ac back as far as possible, preferably by adding fins near the rear of the vehicle. It can also be done with thrust vectoring.
:endresult
The end result at either mach number will be a spinning projectile which eventually tears itself apart due to the propellant chambers experiencing accelerative forces on non-loadbearing walls.
If by some miracle of engineering this does not occur, he would still (probably) not survive sustained flight at Mach 4 in this vehicle. The ballistic coefficient of the nose appears to be too low, which will cause a concentration of aerodynamic heating at the tip. I really can't tell for sure from the picture, but hypersonic vehicles are generally designed with blunt noses so that the wave detaches from the body, allowing the heat to dissipate. If it stays attached there will be a small region in which a layer of incredibly high entropy develops which will cut through steel like a knife through warm butter. For more details, search the web for pictures of what happened to the scramjet NASA tried to hang from an X-15 in the 60's.
FWIW a (statically stable!) titan IV experienced rotationally induced structural failure early in the program when an engine malfunctioned, causing the rocket to become unstable. It is an incredibly important concept that Walker seems to have completely overlooked.
Don't get me wrong; I hope this guy succeeds. I really, really do, partly because I admire his courage and tenacity and partly because it will provide an immeasurable benefit to space privatization advocates everywhere. Since I am an aero type, I stand to benefit tremendously from explosive growth in that sector of the economy. Unfortunately, he won't do it with this design, which makes it exceedingly frustrating-- because it really isn't that hard to design a rocket to do what he wants to do...
Rev Neh
Rambus wasn't awarded the "804 patent" until 21 September 1999. So they didn't sit on it all that long before defending their rights.
In this case, the single point of failure rests with the USPTO- for taking 10 years to read a piece of paper and put a stamp on it. If they had done their job correctly, we would have been paying royalties to Rambus since 1990 or so. (Whether or not this is good or bad is left as an exercise for the student).
Rev Neh
Thanks for that link- it is quite interesting. I had never seen RSR before, but will definitely use it in the future. Hopefully about 10,000 other people will see it and provide a large enough set of data points for its evaluation of sellers to be worth something...
Rev Neh