Anyone have a favorite spot they like to go near Los Angeles that isn't too far away?
Depends on what you mean by "too far away."
LA not only has light pollution, it has particulate pollution to scatter it (hell, I lived there something like six months before the wind came up one day, and I realized that the city was surrounded by mountains!). I missed Halley's Comet because of all that light pollution...
For serious watching, you're going to have to get out of the Basin -- and unfortunately that's the direction everyone is moving, and taking their lights with 'em. A couple of years ago I was at Edwards AFB for a couple of days, and it was even getting bright there... You'll have to drive a few hours, no matter which way you head, but I'd think north or northeast would take you into darkness fastest. Southeast would be my second choice.
Yep, it's interesting: if you go to that http://www.isupportthemonolith.org/ site, it has a link to "http://www.iopposethemonolith.org"... which resolves to
http://www.speakeasy.org/~priapus/monolith.htm
Nope, it's not associated with Speakeasy... heh, heh...
The problem is we can claim we are better all we want, but actions speak louder than words and in the large scale engineers in the 60s make us look like wussies as far as actions are concerned.
So do the designers and builders of the Egyptian pyramids, for an equivalently-majestic example.
None of these have met their match in the last 30 years.
Ah, but I have to differ with you. Not to take anything away from those grand engineering projects, but:
Concorde has been surpassed by a number of aircraft (although admittedly none of which are passenger aircraft).
SR-71 is a grand old piece of equipment; I've been in the Dryden hanger with two of them, and it was an unforgettable experience. However, do you really think they'd have been retired without a more-capable replacement?;)
Apollo 11; while a very functional design, the Apollo spacecraft is far from "matchless". We haven't gone back to the Moon (which deeply saddens me), but present-day manned spacecraft (X-38, for one) are being designed with much greater understanding than Apollo -- even if they don't have the same mission.
Hydrogen Bomb -- those were re-engineered continually, with better tools as time went on. The last ones designed were far more sophisticated and capable than the first ones -- and now we can simulate the bomb pretty effectively in a computer, without even building it.
Your statement is misleading, I think; the Eiffel Tower is grand, as is the Statue of Liberty. They haven't been duplicated since, but does that mean their engineering is unsurpassed? Hardly... Back then, we just lived with less-optimized hardware.
Your computer couldn't be even designed and built with that level of computer support, you know.
If you had looked at similar projects from twenty years ago, they'd have been quite different. Scientific advance is happening so fast in many areas that the "long range" plans must be continually revised, as we become more aware of what the possibilities are...
Right now Mars missions are difficult enough that they often go wrong -- but we're also doing them for a tiny fraction of what we were spending twenty years ago. We are basically keeping reliability constant (if not actually reducing it) and accepting the cost advantage.
Someday it will be only as difficult to mount an interstellar mission as it is now to send one to Mars; we'll only know that when the fact becomes apparent because of the ongoing feasibility studies.
Twenty years ago, my University used 2 CDC supercomputers to support most all of the research needs of Thirty Thousand students and Thousands of academics.
Yep, so did mine, thirty years ago. And the closest I could get to 'em was the window through which I passes the card deck... Today, I have three computers sitting on my desk, and I use them all in different ways -- but I use them directly.
Twenty years ago, engineers wrote proposals and reports longhand, and made rough sketches and graphs; secretaries typed them; draftsmen and illustrators did pen-and-ink renderings of the graphics. The engineers proofed these and redlined them, and the corrections were often done directly on the originals. Design work was mostly hand-work, with lots of extrapolation and interpolation of graphical data; the few computer runs were expensive in both time and dollars, when they were done at all.
Today, the engineers write their proposals and reports on their desktop computers; edit them there; produce the graphics there and refine it themselves; assemble the graphics and text into a final document; and generally print it out themselves, unless they distribute it electronically -- which they also do themselves. And the bar has been raised for the final product: corrections-by-hand aren't acceptable, and the graphics really need color. The engineering itself involves multiple iterations, with much (even most) of the detailed design actually being done on computer models instead of physical prototypes. And the engineer does most of this work directly, too, unless they truly need a supercomputer run.
It's gotten to where I can work as a single individual and replace an office full of support staff -- which is exactly what I do. Is that wasteful of computers? I don't think so, even though one of my computers basically acts as a file, fax and printer server for one person. It's worth what it costs me to use it for nothing else... it keeps the load of my workstation, and saves me the few minutes a day that it cost me over a few months to buy.
The other point I want to make is this: the analysts who say productivity isn't going up with computer use, are are missing the points I've made above -- particularly the one about the bar being raised.
The greatest, single most important invention in all the history of mankind was the invention of railroads, some 150 years ago.
I'm sorry, you're wrong.
The single greatest invention in the history of mankind was agriculture.
Without that, we'd all still be spending our lives grubbing for today's food, playing hunter/gatherer and being not much more than really bright chimps.
Agriculture changed everything about being human. It made the development of civilization possible, by allowing people to live in larger groups. It enabled everything which has come since.
Not that it has necessarily been a good experience for everyone involved...
Not only is there such a thing, but from all accounts it's debilitating -- some people get hiccups for years at a time. I've even heard of suicide attributed to it... can't find the link, though.
Gawd, I can't imagine years' worth of hiccups; a few minutes is enough to drive me nuts!
You can make your blood slightly more acidic very quickly: rebreathe into a largish paper bag for a couple of minutes (not plastic, please -- it's potentially too effective... you want to keep breathing, right?). CO2 blood levels go up, and you get a touch more acidic.
This is the only real cure for hiccups I've found; it works every time, in just a couple of minutes. Everything else is just rolling the dice, as far as I can tell.
Yeah, there were statistics and such -- he just didn't apply any of them when it didn't suit his anti-Intel rant. For one good example: he faults the P4 for failing to scale well with core speed while running Prime95; yet the 600 and 900MHz Athlons scored essentially identically, so the same charge could be made against the Athlon. But he completely fails to even notice this...
He put up a good facade, but in reality his article wasn't a decent analysis -- it did have its good points, but there was so much BS in there that it was hardly worth the effort.
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Re:What's the american degree for -1?
on
Going Up?
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· Score: 2
Let me assure you that the ideas aren't all mine -- a lot of work has been done on this concept, by a lot of people. Search Google for "tether space elevator" and have fun reading!
About the outer endpoint of the system: typical designs use a large mass (like a small asteroid) at the outer end of the cable. Since it's beyond geosynchronous orbit but still moving around Earth once every 24 hours, it's going too fast for its orbital altitude; it therefore tries to move away from earth, but is kept in place by the cable. The result: enough tension to hold the cable "up." You select the tension by choosing the mass and its location relative to GEO. (Alternatively, you can make the cable longer to achieve the same result; but cable's expensive, while asteroids are relatively common.)
To answer your question about connecting it to the ground: The proposals I've seen usually put a large "foundation" in the ground, and attach the bottom end of the cable to that. A rather similar thing gets done at the ends of a large suspension bridge: the cables at each end are pulling toward the center of the bridge, and must be anchored. I suppose an alternative would be to attach it to bedrock, but I think I'd rather engineer the attachment -- that way I would know exactly what it's capable of handling.
You are of course right -- there is shear stress from winds. But the original poster was arguing that it was the mismatch between orbital velocity and cable velocity at every altitude except geosynchronous orbit, which introduces shear forces. This just isn't physical -- it's based on a misapprehension of the problem, and this is what I was addressing in my reply.
While there are aerodynamic forces on the cable, they're fairly small compared to the tensional forces, and can be managed by guy wires... just as with any tower.
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Re:What's the american degree for -1?
on
Going Up?
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· Score: 3
Your idea isn't basically wrong, but it's an extreme case. What you can do is make life easier by changing the diameter of the cable to match the local loading: at geosynchronous orbit, where the loads are highest (because the entire cable is "hanging" from GEO, both inwards and outwards) the cable is largest, and it tapers down as it goes each way. This reduces the total weight of cable needed, and also reduces the necessary strength of materials by a huge factor.
Actually, you've just done a great job of justifying the use of beanstalks tethers. Sure, at the moment we're materials-limited -- but notice the fact that we had a similar situation some 50 years ago with respect to the very computer technology you used to post your comment.
There's nothing fundamental in the physics that prevents "space elevators;" it's just a materials problem. We'll get there soon enough...
(As for your "big-time means of space travel for the construction" comment: we need one asteroid, which could be brought back by a robotic mission, and one minimum-strength tether line in geosynchronous orbit. Unreel that line in both directions, grab the lower end, and use that line as the first strand of the elevator -- you can run all the remaining structure up from the bottom, increasing capacity as you go. If capturing the asteroid at the right moment makes you nervous, you can drag the counterweight mass up the elevator too -- it just takes a little bit longer, and uses some more electricity.)
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Re:Silly question about vacuums
on
Going Up?
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· Score: 1
No, than you would create an atmosphere on the moon!
Why? Just because you have a tube running between the Earth and Moon (ignoring the problems with that, which are huge), you haven't repealed gravity -- which is what holds the air on Earth. The air in the tube's not going to decide to go somewhere else, just because you put a wall around it.
You put the bottom end on the equator, and the center of mass in geosynchronous orbit; the counterweight is above GEO. Then the "beanstalk" is in pure tension, with no shear at all.
I think you're trying to put all the different parts into orbit, whereas only the GEO point is moving at orbital speed. Sure, the parts above and below that aren't (lower tries to fall down, upper tries to "fall" up) -- but they can't go anywhere because the structure holds them in a fixed relationship. In tension...
Huh... I hadn't seen that particular formulation of the problem before. A Google search returned this page, which is just a summary without references, and this one, which isn't exactly on the same topic but does give some numbers. In both cases, the limiting mass (which depends on the Equation of State for matter at extreme densities, which isn't known) is far greater than known neutron star masses, though.
In any event (and this is not my specialty, so take this with the standard grain o' salt), the reason that a collapsar is expected to stop collapsing at neutron-star stage is that the neutron degeneracy pressure (basically, the Pauli Exclusion Principle in action) is able to resist the mutual gravitational forces up to some limit -- by calculation, 1.4 to 1.8 solar masses, although it appears that a value of 2.3 solar masses has been observed. Clearly, though, greater densities can exist, because if the limiting mass is exceeded the collapse continues -- to form a black hole, if you accept the present standard formulations of the problem. It's just that we don't know of a stronger force than neutron degeneracy, which will be able to resist the gravitational collapse. During the formation event (typically a supernova), if the collaspe forces (gravitation, implosion) exceed the neutron degeneracy forces, there's nothing to stop the continued collapse (through higher densities) to a black hole. Our lack of knowledge doesn't mean there's not a further stable state, though -- only that we don't know about it. Some scientists have speculated that a further point might exist in a quark star, which would consist (at least in its core) of free strange quarks. But some models of quark stars end up with lower densities than neutron stars... the problem is that we just don't know enough, yet.
(BTW, there's good info here on neutron stars, from a specialist.)
The human eye/brain combination is great at picking up things that look familiar -- especially faces. Even when they're not there... like the Cydonia "face" on Mars.
Problem is, once someone sees something like that, it's almost impossible to convince them it's just an illusion, a coincidence of light and shadow. Check out the pic that Yahoo has up now -- almost nothing from the original "faces" is there. It's just the original angle that did it.
Matter of fact, they do. Their shuttle is called "Buran," which means "snowstorm" IIRC; it was designed to be launched with the Energia booster.
Buran is extremely close to the Shuttle in general design, although quite a few details are different. It had exactly one flight (unmanned) before the USSR ran out of money, so all the hardware has been mothballed (at best). One of the testbed spacecraft is now in Gorky Park, used as an amusement ride...
So you're correct in a way: The Russians don't have an active shuttle at the moment. But they do indeed have one.
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Now wait a damn minute!
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Green Mars
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· Score: 3
At the moment pieces of one of those martian meteorites, Dar al Gani 476, are being commercially sold for around $300 a gram (search for "DaG476" in the page)...
I'm a farm boy; I can assure you that asparagus and potato plants aren't exactly tiny. If this guy grew asparagus and potatoes in this soil, he either had a huge budget or he didn't grow the plants very large. Matter of fact, the meteorites themselves almost certainly didn't weigh more than a few pounds each -- most of 'em are pretty small. And I doubt that the owners would allow someone to use the whole thing up for a couple of plants, and even if he did he wouldn't grow either crop to maturity in a pound or two of soil!
My guess is that he grew only sprouts and compared a few days growth, using a few grams of material. The only other way to manage it would be to use the samples to prepare a larger quantity of chemically-similar soil, and grow the test plants in that, but the story doesn't indicate that at all. Too bad there isn't a link to the research paper.
Actually, I appreciate that... back in college (which was before most/.ers were born, I think) I did some work on prosthetic arms, which involved trying to pick up and use neural signals at any of several points. While there's been progress since then, it hasn't been impressive enough for me to realistically consider using the technology, even now.
I want MEMS accelerometers embedded in my fingertips so I can just wiggle my fingers and have text appear on the screen...
Oh, you're making it so complicated!
Rather than think about what you want to type, wiggle your fingers, sense that movement, interpret that movement, send the data somewhere, pick it up somewhere else... just tap right into your brain and use that data in the first place! Leave the meat out of it...:)
The datahand idea is maybe not too bad. but I'd rather be able to move my hands around freely while having the "keyboards" strapped to my hands...
Interesting that you said that. Years ago I saw some info on an early prototype of the Datahand; in this particular incarnation, each handpad acted as a mouse -- one for coarse control, the other fine (like a vernier). You had to move your hands around...
Of course, it's not clear that they're worse off for having dropped that idea.:)
I can imagine the noise level at a bysy department with fifty people dictating to their WP. Or an airplane full with people working. I think voice control is not nearly as good an idea as it seems at first.
Especially if your computer starts taking their dictation... notice how you always seem to be too close to some loudmouth?
Slashdot Mirror
Depends on what you mean by "too far away."
LA not only has light pollution, it has particulate pollution to scatter it (hell, I lived there something like six months before the wind came up one day, and I realized that the city was surrounded by mountains!). I missed Halley's Comet because of all that light pollution...
For serious watching, you're going to have to get out of the Basin -- and unfortunately that's the direction everyone is moving, and taking their lights with 'em. A couple of years ago I was at Edwards AFB for a couple of days, and it was even getting bright there... You'll have to drive a few hours, no matter which way you head, but I'd think north or northeast would take you into darkness fastest. Southeast would be my second choice.
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http://www.speakeasy.org/~priapus/monolith.htm
Nope, it's not associated with Speakeasy... heh, heh...
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So do the designers and builders of the Egyptian pyramids, for an equivalently-majestic example.
Your point would be?
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Ah, but I have to differ with you. Not to take anything away from those grand engineering projects, but:
Concorde has been surpassed by a number of aircraft (although admittedly none of which are passenger aircraft).
SR-71 is a grand old piece of equipment; I've been in the Dryden hanger with two of them, and it was an unforgettable experience. However, do you really think they'd have been retired without a more-capable replacement? ;)
Apollo 11; while a very functional design, the Apollo spacecraft is far from "matchless". We haven't gone back to the Moon (which deeply saddens me), but present-day manned spacecraft (X-38, for one) are being designed with much greater understanding than Apollo -- even if they don't have the same mission.
Hydrogen Bomb -- those were re-engineered continually, with better tools as time went on. The last ones designed were far more sophisticated and capable than the first ones -- and now we can simulate the bomb pretty effectively in a computer, without even building it.
Your statement is misleading, I think; the Eiffel Tower is grand, as is the Statue of Liberty. They haven't been duplicated since, but does that mean their engineering is unsurpassed? Hardly... Back then, we just lived with less-optimized hardware.
Your computer couldn't be even designed and built with that level of computer support, you know.
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Right now Mars missions are difficult enough that they often go wrong -- but we're also doing them for a tiny fraction of what we were spending twenty years ago. We are basically keeping reliability constant (if not actually reducing it) and accepting the cost advantage.
Someday it will be only as difficult to mount an interstellar mission as it is now to send one to Mars; we'll only know that when the fact becomes apparent because of the ongoing feasibility studies.
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Yep, so did mine, thirty years ago. And the closest I could get to 'em was the window through which I passes the card deck... Today, I have three computers sitting on my desk, and I use them all in different ways -- but I use them directly.
Twenty years ago, engineers wrote proposals and reports longhand, and made rough sketches and graphs; secretaries typed them; draftsmen and illustrators did pen-and-ink renderings of the graphics. The engineers proofed these and redlined them, and the corrections were often done directly on the originals. Design work was mostly hand-work, with lots of extrapolation and interpolation of graphical data; the few computer runs were expensive in both time and dollars, when they were done at all.
Today, the engineers write their proposals and reports on their desktop computers; edit them there; produce the graphics there and refine it themselves; assemble the graphics and text into a final document; and generally print it out themselves, unless they distribute it electronically -- which they also do themselves. And the bar has been raised for the final product: corrections-by-hand aren't acceptable, and the graphics really need color. The engineering itself involves multiple iterations, with much (even most) of the detailed design actually being done on computer models instead of physical prototypes. And the engineer does most of this work directly, too, unless they truly need a supercomputer run.
It's gotten to where I can work as a single individual and replace an office full of support staff -- which is exactly what I do. Is that wasteful of computers? I don't think so, even though one of my computers basically acts as a file, fax and printer server for one person. It's worth what it costs me to use it for nothing else... it keeps the load of my workstation, and saves me the few minutes a day that it cost me over a few months to buy.
The other point I want to make is this: the analysts who say productivity isn't going up with computer use, are are missing the points I've made above -- particularly the one about the bar being raised.
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I'm sorry, you're wrong.
The single greatest invention in the history of mankind was agriculture.
Without that, we'd all still be spending our lives grubbing for today's food, playing hunter/gatherer and being not much more than really bright chimps.
Agriculture changed everything about being human. It made the development of civilization possible, by allowing people to live in larger groups. It enabled everything which has come since.
Not that it has necessarily been a good experience for everyone involved...
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Gawd, I can't imagine years' worth of hiccups; a few minutes is enough to drive me nuts!
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This is the only real cure for hiccups I've found; it works every time, in just a couple of minutes. Everything else is just rolling the dice, as far as I can tell.
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He put up a good facade, but in reality his article wasn't a decent analysis -- it did have its good points, but there was so much BS in there that it was hardly worth the effort.
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About the outer endpoint of the system: typical designs use a large mass (like a small asteroid) at the outer end of the cable. Since it's beyond geosynchronous orbit but still moving around Earth once every 24 hours, it's going too fast for its orbital altitude; it therefore tries to move away from earth, but is kept in place by the cable. The result: enough tension to hold the cable "up." You select the tension by choosing the mass and its location relative to GEO. (Alternatively, you can make the cable longer to achieve the same result; but cable's expensive, while asteroids are relatively common.)
To answer your question about connecting it to the ground: The proposals I've seen usually put a large "foundation" in the ground, and attach the bottom end of the cable to that. A rather similar thing gets done at the ends of a large suspension bridge: the cables at each end are pulling toward the center of the bridge, and must be anchored. I suppose an alternative would be to attach it to bedrock, but I think I'd rather engineer the attachment -- that way I would know exactly what it's capable of handling.
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While there are aerodynamic forces on the cable, they're fairly small compared to the tensional forces, and can be managed by guy wires... just as with any tower.
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There's nothing fundamental in the physics that prevents "space elevators;" it's just a materials problem. We'll get there soon enough...
(As for your "big-time means of space travel for the construction" comment: we need one asteroid, which could be brought back by a robotic mission, and one minimum-strength tether line in geosynchronous orbit. Unreel that line in both directions, grab the lower end, and use that line as the first strand of the elevator -- you can run all the remaining structure up from the bottom, increasing capacity as you go. If capturing the asteroid at the right moment makes you nervous, you can drag the counterweight mass up the elevator too -- it just takes a little bit longer, and uses some more electricity.)
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Why? Just because you have a tube running between the Earth and Moon (ignoring the problems with that, which are huge), you haven't repealed gravity -- which is what holds the air on Earth. The air in the tube's not going to decide to go somewhere else, just because you put a wall around it.
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You put the bottom end on the equator, and the center of mass in geosynchronous orbit; the counterweight is above GEO. Then the "beanstalk" is in pure tension, with no shear at all.
I think you're trying to put all the different parts into orbit, whereas only the GEO point is moving at orbital speed. Sure, the parts above and below that aren't (lower tries to fall down, upper tries to "fall" up) -- but they can't go anywhere because the structure holds them in a fixed relationship. In tension...
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In any event (and this is not my specialty, so take this with the standard grain o' salt), the reason that a collapsar is expected to stop collapsing at neutron-star stage is that the neutron degeneracy pressure (basically, the Pauli Exclusion Principle in action) is able to resist the mutual gravitational forces up to some limit -- by calculation, 1.4 to 1.8 solar masses, although it appears that a value of 2.3 solar masses has been observed. Clearly, though, greater densities can exist, because if the limiting mass is exceeded the collapse continues -- to form a black hole, if you accept the present standard formulations of the problem. It's just that we don't know of a stronger force than neutron degeneracy, which will be able to resist the gravitational collapse. During the formation event (typically a supernova), if the collaspe forces (gravitation, implosion) exceed the neutron degeneracy forces, there's nothing to stop the continued collapse (through higher densities) to a black hole. Our lack of knowledge doesn't mean there's not a further stable state, though -- only that we don't know about it. Some scientists have speculated that a further point might exist in a quark star, which would consist (at least in its core) of free strange quarks. But some models of quark stars end up with lower densities than neutron stars... the problem is that we just don't know enough, yet.
(BTW, there's good info here on neutron stars, from a specialist.)
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Problem is, once someone sees something like that, it's almost impossible to convince them it's just an illusion, a coincidence of light and shadow. Check out the pic that Yahoo has up now -- almost nothing from the original "faces" is there. It's just the original angle that did it.
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It's more like every 90 minutes: it's in low earth orbit.
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Buran is extremely close to the Shuttle in general design, although quite a few details are different. It had exactly one flight (unmanned) before the USSR ran out of money, so all the hardware has been mothballed (at best). One of the testbed spacecraft is now in Gorky Park, used as an amusement ride...
So you're correct in a way: The Russians don't have an active shuttle at the moment. But they do indeed have one.
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I'm a farm boy; I can assure you that asparagus and potato plants aren't exactly tiny. If this guy grew asparagus and potatoes in this soil, he either had a huge budget or he didn't grow the plants very large. Matter of fact, the meteorites themselves almost certainly didn't weigh more than a few pounds each -- most of 'em are pretty small. And I doubt that the owners would allow someone to use the whole thing up for a couple of plants, and even if he did he wouldn't grow either crop to maturity in a pound or two of soil!
My guess is that he grew only sprouts and compared a few days growth, using a few grams of material. The only other way to manage it would be to use the samples to prepare a larger quantity of chemically-similar soil, and grow the test plants in that, but the story doesn't indicate that at all. Too bad there isn't a link to the research paper.
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Mostly I was trollin' for a 1: Funny ;)
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Oh, you're making it so complicated!
Rather than think about what you want to type, wiggle your fingers, sense that movement, interpret that movement, send the data somewhere, pick it up somewhere else... just tap right into your brain and use that data in the first place! Leave the meat out of it... :)
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Interesting that you said that. Years ago I saw some info on an early prototype of the Datahand; in this particular incarnation, each handpad acted as a mouse -- one for coarse control, the other fine (like a vernier). You had to move your hands around...
Of course, it's not clear that they're worse off for having dropped that idea. :)
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Especially if your computer starts taking their dictation... notice how you always seem to be too close to some loudmouth?
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