Hob #113,
GOTO JESUS and other unstructured forms of theological flow control are commonly associated with batch processing of compiled prayers. I much prefer the more traditional, if somewhat less efficient, intepreted prayer, with immediate feedback.
In short, Give Me That Old Real-Time Religion...
Teresa @ 54: I never metastable nanocrystalline metal hydride I didn't like.
One does it because one's hovercraft is full of eels.
The DC-X program was halted by copyright concerns from DC and Marvel.
Thereby allowing Lockheed Martin and Disney to proceed with the Mickey Mouse X-33 program....
Victor S. -- not quite right. DC-X was a project of the Strategic Defense Initiative Organization, SDIO. (The SDIO division that funded it was run by then-COL Pete Worden, who is now director of NASA Ames. The actual program manager was an Air Force major, Jess Sponable, and one of the "pilots" was filker Mitchell Burnside-Clapp. I was at the first public flight test, and drove back from the test range to Las Cruces with Pete Worden, pitching a new program to him. My boss was driving, and kept turning around to join the back-seat discussion -- nearly ran us off the road several times.)
DC-X was damaged by an in-flight fire on its last flight. It autolanded successfully despite having a gaping hole blown in its side, but needed substantial repairs. At that point it was under heavy budgetary and political attack -- Clinton was in office, SDIO was being cut back, and DoD was raiding anything space-related for funds to keep their main new-launch-vehicle program (NLS) alive. The net result was that NASA got named the sole national agency for reusable launch vehicle development. DC-X was transferred to NASA, rebuilt as the DC-XA, and made a few more flights, but on its last flight the ground crew forgot to reconnect a hose in the landing gear. It flew, set down, and one landing leg didn't extend, so as soon as the engines shut off it fell over, rupturing tanks and triggering an explosion that destroyed it.
So it was killed by funding problems, national politics, and plain old human error, not NASA technology choices. DoD might have done a better job of running the program, and the one that followed it(NASA did pick the high-tech/high-risk option for X-33, and it failed badly). But it's equally possible DoD would have killed the program completely after the first fire, had NASA not taken it over.
Dave Kuzminski: I killed two Selectrics ... The other was an MTST version that had two magnetic tape (MT) drives so you could record what you typed and replay it over and over to produce many, many copies. ... When I wounded the MTST, about six cables inside it broke simultaneously.
The IBM Mag Tape typewriters were the only use I know of, ever, of *sprocketed* magnetic tape. The sprocket drive would advance the tape by one hole, and a solenoid would drive the tape head *sideways* across the tape to read or write the character code. That way they could build an entire digital tape unit with only one electronic part: the head amp. Everything else was done with relays.
(IBM really was a world unto itself for a long, long time. They did everything their own way, including running 2741 terminals at 134.5 baud because the synchronous speed of the Selectric mechanism was 13.45 characters/second; at 134.5 baud the motor clutch would never have to drop out between characters, which gave both the fastest typing and the least wear. They used EBCDIC character codes long after the rest of the world pretty much agreed on ASCII, and every system and terminal, it seemed, had a slightly different version of EBCDIC, with the differences seldom documented anywhere. "Obstacles to competitors? Who, us?")
(And I see I've already commented on Making Light here about both the MTST and the big Mergenthaler typesetter I once owned...)
Colin Roald, re the simulation of helicopter recovery of a Saturn V booster:
Oh my god. I must see. You don't have a link, do you?
Sadly, it's not online to my knowledge. You'd have to go to the
Hiller Aviation Museum to see it -- the museum is definitely worth a stop if you're ever in the area. They have lots of other exotic helicopters and aircraft, some one-of-a-kind.
There's a mention of the Saturn recovery plan online here
with slightly different numbers than I recalled, but no pictures, alas.
Oh, lotsa good stuff, and no time to comment (I gotta read ML more often...). I'll just note that a helicopter in autorotation may be easier to figure out if you think about gliders (sailplanes) which, in the absence of updrafts, do the same trick of slowly using up their potential energy (altitude) to maintain their forward velocity. You can model a helicopter in autorotation as two or three gliders flying in small circles, with their wingtips tied together (now *there's* a pilot's nightmare). As far as helicopter lift being "non-Newtonian"... bah, humbug. Momentum is conserved; out of ground effect, the only way you get lift is by accelerating air downward. Wings are better than jets standing on their tails because they interact with a larger volume of air: large volume => large mass => small velocity change for a given force => small amount of energy needed per unit momentum (since energy is proportional to velocity^2).
There's a way-cool exhibit at the Hiller Aviation museum on the SF (the city) peninsula about a proposal, during the early days of the Apollo program, to recover Saturn V booster stages by parachute and reuse them. To avoid dunking the stages in the ocean, they would be plucked out of the air by a *giant* helicopter, with 100-yard-long blades (IIRC) spun by pairs of large jet engines at the tips; the blades spun at something like 10 RPM. They have a video made from the "demo" film, which, in those pre-CGI days, used wooden models hung on wires...
Oh, and metallic glasses? Also known as "microcrystalline" metals. Made by rapid solidification of metals; one way is to shoot a jet of metal against the rim of a rapidly-spinning disk. One of many jokes about the National AeroSpace Plane project (aka the Full Employment for Computational Fluid Dynamicists program) is that, while lots of aerospace designs require Unobtanium to work, the NASP needed Rapidly Solidified Microcrystalline Unobtanium.
Over on TPMCafe, there's a thread on this where people have asked, repeatedly, just how many generals and retired generals there are, and no one has answered. Rumsfeld is quoted as saying today, "There are I don't know what 3, 4, 5, 6,000 generals..."
A quick google turns up a table that says that as of April 30, 2002 there were a grand total of 875 flag officers (Generals/Admirals) more than half of whom (439) had only one star -- all the recent critics have at least two. Subtract out 220 admirals, and there were 655 serving generals, 326 two-star or above.
Flag officers apparently move "up or out" every 4 years, with about half of each grade getting promoted and the rest retiring. That makes the average service time of a general a little under 8 years. Now, even though they retire pretty early (52 to 62, average in the mid 50's. Wow) I don't think they live much more than 30 years on average after retirement. So there are about 4 retired generals per active-duty general -- somewhere around 2600 of them, well over half being one-stars. Limit it to retirees within the last 5 years and it's probably less than 600, maybe 200 with 2 or more stars
So a) Considering his position, Donald Rumsfeld has a pretty poor idea of the number of retired generals, and b) we've heard from roughly 3% of all the 2-star-and-up generals who've retired in the last 5 years, and a much higher percentage of those who actually had something to do with the ground war in Iraq.
Jim (or anyone else) do those numbers look right to you?
That does it. Now I've got to write a book called "Goedel, Escher, Flack."
"Google, Usenet, Blog -- an Unending Grammatic Blight" by Hogless Dufstadter
A ponderous and exceedingly self-referential examination of language, thought, communities, and knitting, told in the form of a flamewar between Achilles and the Tortoise over the true nature of Spam.
Michael Turyn: Can you make a lighter-than air material by creating the equivalent of an aerogel in a vacuum, sealing the outside with a much less permeable material (not very significant for big enough spheres)? Has anyone tried?
Yes, and yes. Lawrence Livermore Labs developed a lot of aerogel technology, much of it during the years I was there, despite JPL getting more press. Among other things, they came up with an organic variant called SEAgel, made from seaweed (agar), which could indeed be made with a mean density less than air at STP and still support 15 psi.
I forget which tech show it was where I helped staff LLNL's booth, but we had an inverted empty fishtank with some pieces of seagel in it, floating at the top. You could (gently) tap them down and they'd float back up.
It's not a very useful technology for balloons, though; the density is only just a little less than sea level air, so even at sea level it has only a fraction of the lifting power of a helium or hydrogen balloon, and the lifting power goes to zero at a few thousand feet.
Graydon wrote: Your lungs work in reverse, so all the oxygen comes back out of your blood; you lose consciousness in about 15 seconds and you die quite promptly thereafter, long before you have time to get cold.
That may be a bit pessemistic, and depends in part on how much oxygen you have in your system and how abrupt the pressure loss is. Wikipedia quotes USAF numbers of 9-12 seconds Time of Useful Consciousness, meaning how long you can still function more or less intelligently, but notes that that complete unconsciousness takes longer. However, Clarke's estimate of a minute or more in _Earthlight_ and the sequence in _2001_ are decidedly optimistic.
Ivory soap, however, will lose consciousness immediately on exposure to vacuum.
(Now you've got me wanting to dig out a vacuum pump from the garage and experiment....)
Julie L: I suppose it's certainly possible to envision bishounen apatosaurs with long, swoopy necks entwining in misty soft-focus yaoi romance, ...
"When Brontosaurs Fall In Love" by Dr. Jane Robinson. Alas, most of the lyrics have left my memory, leaving only snippets:
"A thrill ran down all seventy feet of his saurian nerves."
Sad news. Dimension of Miracles was one of my favorite books for many years, and I can still quote lines from it: "Kettle drums sound ominous note. Ominous note sounds kettle drums." I wonder if Douglas Adams read DoM; Sheckley's planet-building Engineer had much in common with Adams' Magrathea. "We get our subatomic particles from subcontractors" indeed.
I shall have to go reread a few of his stories and hoist a glass to his memory.
Jordin: so if even a Mach 3 bomber couldn't work against Soviet SAMs, we kept on flying B-52's as if they were threats?
Yeah, and they were, sorta. Not to get in too deep, the B-52 operations plans were modified to have them come in at "treetop" level (or as close as they could get in the days before terrain-following radar) with heavy radar jamming, and hope some would survive to reach their targets. They didn't have much better odds than the B-70, but they were much cheaper, and we already had a lot of them. And they were a realistic threat in some fairly plausible (by the logic of the times) scenarios, such as a first strike by the USSR that knocked out most US ICBMs but left enough to wreck the Soviet air defenses.
The Cold War generated some *amazing* weapons systems that, fortunately, never got deployed. _Steam Bird_ by Hilbert Schenck, is a lovely bit of fiction based on another one, the nuclear-powered bomber. I'd better stop now, or I'll start blathering about Project Pluto, the Mach-3 *at sea level* nuclear ramjet drone that LLNL was building around that time....
CHip:I've seen the XB-70 at Wright-Patterson; don't remember it being that big, and I would have thought that the speed would have given it some advantage against SAMs? IIRC, they just couldn't make it fly very well
The XB-70 flew just fine, but one of the two built crashed after an F-104 (being flown by NASA chief test pilot Joseph Walker) got too close to it and was caught in a wingtip vortex. The F-104 flipped over and hit the XB-70, taking off one of its vertical stabilizers. The pilots didn't even notice the impact (!) and kept flying level for a while, but eventually the plane went into an unrecoverable spin and crashed. Impressive photos here
Losing one of two prototypes is a big hit for any program, but the B-70 program was on the ropes anyway because of the rapid improvement in SAMs, as someone else noted. It was becoming clear that even at Mach 3, a high altitude bomber would not survive trying to attack the Soviet Union in a nuclear environment, and that was the only mission where the B-70 made sense. (It's arguable whether the B-2 *ever* made sense....)
Personally, I think George Lucas must have used the XB-70 as seen from the rear as the inspiration for the Imperial Star Destroyer.
Neat XB-70 fact: those turned-down wingtips were actually a major source of lift at Mach 3: the wingtip shockwave bouncing off the underside of the main wing generates lift. Hypersonic aircraft designers call this a "waverider" design, and the XB-70 is the only waverider aircraft that's ever flown.
What truly boggles me is not that these things happened, but that a large fraction of the American public seems to think they're perfectly fine. According to Gallup 35% of the public thinks the Federal government response has been "good" or "very good", and another 20% think it's been OK ("neither good nor bad," not "no opinion"). (State and local governments get 37% "good" or "very good.") What would it take to make these people believe the Federal government screwed up? Mass public executions on prime time TV?
The ballad is Child No. 10, and usually goes by either "The Two Sisters" or "The Twa Sisters."
Or "The TWA Sisters" as a helpful typesetter once corrected one of Off Centaur's cassette inserts.
Vicki's anti-phonetic alphabet is making me wonder what happens when phonemes collide with anti-phonemes.
The jargon is the fundamental particle of incomprehensibility. When a jargon and an antijargon collide, they annihilate each other, resulting in the emission of a pair of high-energy grammar rays.
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| 2009 | 2 |
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| 2004 | 32 |
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| 2002 | 24 |
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