Amateur Telescope Making. Scientific American Publishing Company, 1928. pp 244-245:
Rotating, Mercury Mirror: Dr. R.W. Wood, Professor of Experimental Physics at Johns Hopkins University attempted in 1908 to make an automatically paraboloidal mirror of variable focal length by the theoretically practicable method of rotating on a central, vertical axis a round, shallow pan of mercury. Under centrifugal action the mercury takes on the figure of a true paraboloid. Using a 20 inch pan, a rubber thread transmission and a magnetic clutch, Dr. Wood obtained interesting results, the focal length being varied with ease by changing the speed. Minute irregular disturbances injured the perfection of the mirror's surface, despite the velvety transmission or drive. The mirror was rotated at the bottom of a well, and since it is horizontal, it reflected only the zenith stars; a flat would therefore be required to complete the equipment so that it would take in a large field. The original experiments were described by Dr. Wood in the Scientific American, March 27, 1909, page 240 (out of print -- consult at large public libraries), and in Astrophysical Journal, March, 1909. This interesting experiment was originally proposed in the Scientific American, Dec. 13, 1873, page 365 by someone who signed "D." It is known, however that "D" was David Todd, later to become Professor of Astronomy at Amherst College. Dr. Wood's experiment was not completed. The elimination of the ripples required a constant speed of drive.
The above note was submitted to Dr. Wood with a request for comment. He replied as follows: "The experiments were continued after the publication of the papers, but I never published anything more on it. I got it to work much better the second summer. I put a 20-inch flat over it and had excellent views of the Moon. The final conclusion was that constant speed of drive would eliminate the slight tidal wave, which was all that remained. I did not even have a synchronous motor. One of these, operated on a modern A.C. circuit with the cycle frequency controlled by clock, would be a great improvement. I do not advise anyone to try the mercury mirror, however."
The entry on Mercury Telescopes contains an additional long paragraph on synchronous motors and clock drives that I have not transcribed.
An interesting note. After typing all this in, I went to the front of the book to type in the bibliographical information and was astonished to find that the first page is inscribed, in pencil, presumably with the name of the original owner: R.W. Wood John Hopkins Un.
and the used bookstore price, as purchased by my Wife's Grandfather: $2.00.
Orbiter -- around 80,000 kg. Hard drive -- around 1 kg.
The surface of the orbiter gets intensely hot because the orbiter has to dissipate an enormous amount of heat energy through its surface in order to deorbit.
Once blown free of the shuttle body, the hard drive had orders of magnitude less energy to dissipate. It would have slowed down quickly and would have been tumbling through the air so the generated heat would have been dissipated more evenly than the orbiter, where much of the heat is concentrated on the nose and thin wing leading edge.
The PCB might have acted as a heat shield and protected the platter enclosure while the drive slowed down from reentry speed to free fall speed, or the charring could have come from exposure to fire during the explosion.
I'm glad the data was recovered. I think the shuttle crew would be pleased. It enhances the legacy of the mission.
It's time once again for me to bask in my fleeting moment of USENET glory, when for a few brief shining months 18 years ago, it seemed like half the world was using my Simpsons ASCII art for their signature file.
Question -- how is the conductivity of space elevator cable? Could you have the cable consist of two electrically insulated cables held together somehow, then supply electricity across them?
More importantly, buy the cd/tape/record USED, not new.
When you buy a new CD, you are putting money into the pockets of the RIAA. When you buy a used CD, you put your money into the pocket of whoever last bought the CD, and the RIAA doesn't get a penny.
If you purchase only used CDs and DVDs, you will have achieved all three goals. Plus, by increasing the demand for used movies, you will be increasing the value of your own collection by growing the used digital media market, which will benefit you when you have movies of your own you wish to sell.
The SCO vs IBM assault (funded by Microsoft) is about to implode. Therefore, Microsoft is poised to move on to their next strategy of attacking free software.
Back when I was a university system programmer, I had an officemate named Tim. One day, Tim was poking around and discovered that hundreds of computers all across campus were synchronizing their clocks to his desktop workstation. He quickly figured out why.
The naming standard for desktop machines was to take the employee's first name and concatinate it with the first letter of their last name. So my desktop machine was named "johns.cc.uic.edu". Tim's machine was named "time.cc.uic.edu" because his last name began with "E". (cc meaning a "computer center" machine.)
Apparently many many university departments and users poked around and discovered what was obviously an official time server and configured their computers to synchronize to Tim's desktop machine. Tim, of course, had set his computer's clock by the office clock and never given it a second thought.
Motion picture film has phenomonal resolution. There's a lot of argument about what the "effective resolution" of film is, but you're very, very wrong about how classic movies will look in consumer digital formats.
None of those movies were filmed with DVD in mind, or even with home viewing in mind.
Yes, they were filmed with *THEATRES* in mind, back in the days when theatre screens were gigantic. Back then, movies were filmed on extremely high resolution, fine grain film stock, and they filmed using arc lamps to provide the enormous amounts of light necessary to expose the ultra-high resolution film stock.
It's difficult to compare film resolution to video resolution because they are largely apples and oranges. If you do a google search, you'll find a lot of opinions in the 20-50 equivalent megapixel range. When motion picture studios render computer graphics for transfer to 35mm film, and want to avoid pixelation in the release prints, the images are rendered at 6K x 4K, or 24 megapixels per frame. This is also the resolution used when motion picture negatives are scanned for restoration.
Also, modern motion picture film has a 1000:1 contrast ratio. Older black and white film stocks used much more silver than today, and had an even higher contrast ratio.
The highest available HDTV resolution is 1920x1080, or 2 megapixels per frame, or 1/12th the effective resolution of motion picture film. It's not even close.
The negatives will surely have deteriorated over time
That would have been true 10 or 15 years ago. By now, most of the studios have recognized the value of their libraries, and a large number of classic movies have been restored. Ted Turner took a lot of heat for "colorizing" his motion picture holdings, but the first step he took on each movie was to pay for a complete, top-quality black and white film restoration/preservation of the best existing preprint material.
The amout of deterioration depends on how well the negatives were processed and stored. Technicolor dye transfer prints do not fade, and if a studio has one in mint condition, it can provide a perfect color record. (George Lucas lucked out in that Star Wars was printed by Technicolor in Britain using the old dye-transfer process, so a few prints have survived with perfect, unfaded color. This allowed him to complete a near-perfect restoration of the film.)
Color films from the 50s to mid-80s filmed on Eastman negative film have problems with color fading (which can be corrected in most cases.) In the mid-80s Kodak improved their film stocks, and greatly reduced color fading. Restored movies don't have "spots [and] hairs on the film", because those are not on the camera negatives. When a movie is completed, the hand-spliced-together camera negative (which has been only ever handled in a clean room with cotton gloves) is used to make a small number of high-resolution interpositives. Then the camera negative goes into a film can and into a climate controlled vault.
Those interpositives are used to make a larger number of internegatives, which are then used to print all of the release prints that are sent to theatres and gather the "spots and hairs" that you are referring to. If, for some reason, the camera negatives are overused, and become dirty and scratched, the dirt and debris can be cleaned off, and scratches on the film are eliminated by "wet-gate" printing, where the film is wetted with a liquid just prior to scanning that makes the scratches disappear. You are seriously underestimating the motion picture restoration industry. Given enough money, virtually any motion picture, in any condition can be made to look like new *in the theatre.*
In short, wait and see. Old movies are going to look fantastic when scanned for HDTV. And the best news is that they are going to look even better for about the next 5 generations of consumer video media.
No consumer video system has even come close to the image resolution of motion picture film, and HDTV is no exception.
Lyrics that made no real sense worked for Van Halen with David Lee Roth
Heh. When I was in high school one of my favorite lyrics from "current" rock was from "Jump".
"Well can't you see me standing here I've got my back against the wrecking machine"
Then I found out years later that the lyric was actually "record machine" and it killed the song for me. I had a mental image of Roth standing up to this apocolyptic robot of death, back against the wall, when he was actually just a dork hanging out in front of the jukebox. Sheesh.
Yeah. What do you have to say about black musicians like Ray Charles who often made top-selling albums of songs that happened to be written by white songwriters?
For instance, Modern Sounds in Country and Western Music contains a top-ten selling cover of "You Don't Know Me", originally recorded by Eddy Arnold. Eddy Arnold was managed by Col. Tom Parker, who would go on to become Elvis Presley's manager.
So was Ray ripping off whitey? Or did he, like Elvis, recognize what was brilliant in someone else's work and reinterpret it to make it his own?
As the Green Party Presidential candidate, would you support the disposal of fission byproducts by shooting them into the sun?
Gads I hope not. Take a look at this 1999 article for a reality check about the reliability of rockets:
Anxieties were heightened when three launches failed within the eight-day period that ended a week ago Tuesday. One of those malfunctions involved a Titan IV rocket, the launch vehicle the U.S. military depends on to put its highest priority satellites into orbit. The Titan IV has now suffered three failures in three flights since August, including a fiery explosion over the launch pad at Cape Canaveral Air Force Station that destroyed a $1 billion top-secret intelligence satellite.
In addition to the Titan mishaps, a commercial Athena rocket lost a satellite in April, and last Tuesday, the new Delta III rocket suffered its second failure since August....
I'd much rather have nuclear waste travelling down railroad tracks or in highway convoys than to regularly launch the practical equivalent of a maximum-damage "dirty bomb" and effectively roll the dice again and again, hoping that none ever blow up over Florida or the ocean or fail to reach orbit and burn up in the atmosphere.
Putting nuclear waste in rockets would probably be just about the most irresponsible thing you could do with it short of flying around and dumping it out of planes or shovelling it into incinerators.
As of a few years ago, I was a system administrator at a university. One of the more esoteric things I did was to bring ECAP over to VM/CMS.
ECAP (Engineering Circuit Analysis Program) was written around 1965 by IBM. I never used it (other than to port it and test it), but I believe that it basically solved simultaneous differential equations.
The interesting thing was that all that we had was a binary originally written for and compiled on an IBM 1620 computer. At some point, a 1620 emulator was written for OS/360, allowing the original binary to run on the IBM 360 architecture. It was running as an MVS loadlib. I moved the binary to VM/CMS, and it ran perfectly fine in OS emulation mode.
So, we have the 1620 binary (in the form of a virtual punch card deck) running under a 1620 emulator running under an MVS emulation library running in VM/CMS on an IBM 3090 in a virtual machine, emulating an IBM 370.
All for an old professor whose tenure probably predated the 1620 computer that the software originally ran on.
Kim Jong Il, general secretary of the Workers' Party of Korea and chairman of the DPRK National Defence Commission, gave on-the-spot guidance to the Chongchongang Machine Factory.
The leading officials of the factory greeted him.
He looked round several production processes to familiarize himself with technical equipment and production.
He was very pleased to see that the workers of the factory who are boundlessly loyal to the Party and revolution are making brilliant achievements daily in the herculean undertaking of building a great prosperous powerful nation and are keeping the factory and workplaces clean.
There are ways around the carnival booth problem. It all depends on what you do with the information.
Just as an example, if the CAPPS data were used for the sole purpose of assigning air marshals to flagged flights:
o It would not interfere with the random-search system and reduce those odds. Thus, a CAPPS system would be at least as efficient as a non-CAPPS system in detecting contraband.
o It would not enable the carnival booth algorithm, because there would be no feedback mechanism for those individuals "scouting out" the system.
o It would not harass innocent passengers. If an innocent passenger falsely trips the alert criteria for whatever reason, and there are air marshals anonymously monitoring him or her for the entire flight, the passenger will never know that they had been singled out and monitored. A far cry from being harassed every time you fly, or having to fight an airline "ban."
Using the CAPPS II tool to pull people out of line and search them or tell them that they won't be allowed to fly would be just plain stupid. The purpose is to catch terrorists, not to harass them and tip them off during their recon. missions.
Since RMS coined the term "free software", there has been talk about the semantic problems inherit in the term "free software." I've thought for a long time that RMS made a basic mistake when he coined the term "free software." The term has problems. I want to discuss two in particular.
First off, in the English language, the adjective "free", when paired with an inanimate noun, means free of charge. It does in every other context. If I say that I got a "free toaster", then you will assume that I meant that I didn't pay anything for it, not that the toaster comes with special rights. So the very term for the movement is equally open to deliberate misrepresentation, and simple misunderstanding. If you want a meme to become widespread, but it can't be understood without a semantic interpretation, then you have a problem.
The second problem is that "free" is not really an attribute of the software. Free software is "free" because of a choice by the copyright holder.
So why not "freed software" instead.
This term would solve both problems. On the one hand, it would extinguish the erroneous interpretation that the software is merely "free of charge", because the word "freed" is never used in that context. At the very least, someone who never heard that term would wonder (and perhaps ask) what it specifically meant, instead of immediately reaching the erroneous conclusion (which works against the movement) that "free software" is about zero-cost or public domain software, based on the way the word "free" is used as an adjective in the rest of the English language.
On the other hand, it correctly attributes the action of making software into "freed software" to the author/copyright holder. Freeing someone is considered to be a noble gesture. An act not just of giving, but of elevating he whom is freed. A freed slave becomes a freedman. I truly believe that the act of releasing software under the GPL is a noble gesture. It is an act of giving to the community. The term "freed software" would refocus the emphasis from the software to the programmer. And that's a good thing. What we need now isn't more free software. We need more people to make the transition from keeping their software proprietary to releasing their work as freed software.
I also believe that a great deal of the success of the term "open source" is because it is semantically correct -- the opposite of open source is closed source. That's something that people intuitively understand. I'm wondering if a careful redefinition of the free software movement as the "freed software movement" would have the same effect for RMS's ideals and goals.
The presence or absence of a scholarly degree on the part of a theorist says absolutely nothing about the merits of a theory. Nor does the amount of money invested in the enterprise of realizing the theory. I learned that one from cold fusion.
Re:Conservation of angular momentum is the fatal f
on
Space Elevators Going Up
·
· Score: 4, Interesting
Apparently my objection is unfounded. It has been pointed out to me that the liftport site discusses this issue:
If you go through the math quantitatively, the angular momentum for the climbers requires a few newtons of force over the one-week travel time, and we do that easily with our many tons of material in the anchor and the counterweight. The additional angular momentum will eventually be recovered from that of the entire Earth.
The quantities really are tiny, but just to be complete, a climber going up pushes the entire elevator slightly to the east, causing it to lean. However, the ribbon recovers for the same reason that it stays up in the first place. Centripetal acceleration is acting on the counterweight pulling it outward, and the lost angular momentum is replaced very quickly (essentially as fast as it is lost). The ribbon will never lose enough angular momentum to even deflect a single degree, let alone fall. The extra angular momentum is stolen from the Earth's rotation...
The site doesn't actually run through the numbers or mention how long this recovery time would be. The logic does make sense -- if the tether becomes slanted relative to the surface of the earth (my objection), then by definition there is a lateral component to the centripetal force on the tether, which should allow the sky station to steal some angular momentum from the earth. at some unspecified rate.
The site doesn't actually run through the numbers or mention how long this recovery time would be. If any physics mavens are irritated enough by my parent post to actually run the numbers, I'd be genuinely interested in seeing the solution worked out.
Conservation of angular momentum is the fatal flaw
on
Space Elevators Going Up
·
· Score: 3, Informative
There is one problem that doesn't seem to be addressed -- the problem of imparting the necessary angular momentum to the elevator car as it rises.
As the car rises, from the point of view of the ground, it will appear that the car is dragging the tether westward. As the car continues to rise, the angle of the tether-bend will increase, pulling the base station down into a lower orbit, If the system doesn't "crack the whip" and snap off the sky station, or induce a huge oscillation in the tether/sky station, it will at the very least leave the sky station in a lower orbit, and the tether "slanted" westward. The more mass you send up the tether, the sharper the slant, and the worse the problem becomes.
The following experiment graphically illustrates the basic problem. The "space elevator" does not behave like an elevator.
Take a long piece of string or fishing line and tie a medium bolt to the end. Go outside to a large open area. Take a second bolt of similar size, thread it through the line, and hold it in your hand along with the free end of the fishing line. Now start spinning in a circle and let the line play out until the bolt is spinning at the end of the line. For the purposes of this demonstration, you are the earth, the fishing line is the elevator, and the tied bolt is the space anchor. You are looking straight "up" the elevator tether at the space station at the "top". Notice how your hand (the base station on the surface of the earth) is moving fairly slowly (with respect to your torso, the core of the earth), but the bolt at the end of the line (sky station) is whipping around at high speed? This means that the bolt on the end of the string has a lot of angular momentum, and the bolt in your hand has considerably less angular momentum. Now let go of the bolt you are holding while you continue to hold the string. The "elevator car" bolt will proceed to travel "up" the string into space until it comes to a stop at the "space station." However, the bolt will NOT simply rise straight up the line like an elevator car. Instead it will drag the line in the direction opposite to the direction you are rotating, and will "crack the whip" somewhere near the end of the travel. When you are all finished, the line will be oscillating "east to west" (forward/backward) relative to your hand.
Not what you may have been expecting based on the conceptually flawed "elevator" analogy.
Now there are limits to this demonstration. For instance, the actual elevator car will be speed controlled, not flying freely like the travelling bolt, and there are massive differences in scale and speed. But even if you solved all the engineering problems you can, the basic problem of conservation of angular momentum remains, and it's a show-stopper.
The oscillation problem could theoretically be avoided by carefully timing the rise of the elevator car, but the killer is conservation of angular momentum. As the elevator approaches the sky station, it will drag the tether westward and pull the sky station into a lower orbit. It can't help but do it, because as the elevator car reaches the sky station, it is going to have to match speed with the sky station. In order to do this, it will have to "steal" some angular momentum from the sky station, and even in a best-case scenario, where the timing is done absolutely perfectly and no oscillation is induced, the system will balance the equation by dropping the sky station into a lower orbit, and leaving the tether "slanted" westward. Bringing the elevator car back down again (perfectly timed once again to avoid oscillation) would straighten out the tether, but if the purpose of the space elevator is to sling things into space, then it becomes clear that the entire scheme isn't going to work. Any object lifted to the sky station is going to "steal" angular momentum from the sky station, and once you let go of anything, you will never get back that angular momentum, and there will be no way to straighten out the t
Slashdot Mirror
Sending a mouse to disturb the eternal footprints of giants. Sort of a metaphor for the current state of NASA, sadly.
The following is excerpted from:
Amateur Telescope Making.
Scientific American Publishing Company, 1928.
pp 244-245:
Rotating, Mercury Mirror: Dr. R.W. Wood, Professor of Experimental Physics at Johns Hopkins University attempted in 1908 to make an automatically paraboloidal mirror of variable focal length by the theoretically practicable method of rotating on a central, vertical axis a round, shallow pan of mercury. Under centrifugal action the mercury takes on the figure of a true paraboloid. Using a 20 inch pan, a rubber thread transmission and a magnetic clutch, Dr. Wood obtained interesting results, the focal length being varied with ease by changing the speed. Minute irregular disturbances injured the perfection of the mirror's surface, despite the velvety transmission or drive. The mirror was rotated at the bottom of a well, and since it is horizontal, it reflected only the zenith stars; a flat would therefore be required to complete the equipment so that it would take in a large field. The original experiments were described by Dr. Wood in the Scientific American, March 27, 1909, page 240 (out of print -- consult at large public libraries), and in Astrophysical Journal, March, 1909. This interesting experiment was originally proposed in the Scientific American, Dec. 13, 1873, page 365 by someone who signed "D." It is known, however that "D" was David Todd, later to become Professor of Astronomy at Amherst College. Dr. Wood's experiment was not completed. The elimination of the ripples required a constant speed of drive.
The above note was submitted to Dr. Wood with a request for comment. He replied as follows: "The experiments were continued after the publication of the papers, but I never published anything more on it. I got it to work much better the second summer. I put a 20-inch flat over it and had excellent views of the Moon. The final conclusion was that constant speed of drive would eliminate the slight tidal wave, which was all that remained. I did not even have a synchronous motor. One of these, operated on a modern A.C. circuit with the cycle frequency controlled by clock, would be a great improvement. I do not advise anyone to try the mercury mirror, however."
The entry on Mercury Telescopes contains an additional long paragraph on synchronous motors and clock drives that I have not transcribed.
An interesting note. After typing all this in, I went to the front of the book to type in the bibliographical information and was astonished to find that the first page is inscribed, in pencil, presumably with the name of the original owner:
R.W. Wood
John Hopkins Un.
and the used bookstore price, as purchased by my Wife's Grandfather: $2.00.
How about that!
Orbiter -- around 80,000 kg.
Hard drive -- around 1 kg.
The surface of the orbiter gets intensely hot because the orbiter has to dissipate an enormous amount of heat energy through its surface in order to deorbit.
Once blown free of the shuttle body, the hard drive had orders of magnitude less energy to dissipate. It would have slowed down quickly and would have been tumbling through the air so the generated heat would have been dissipated more evenly than the orbiter, where much of the heat is concentrated on the nose and thin wing leading edge.
The PCB might have acted as a heat shield and protected the platter enclosure while the drive slowed down from reentry speed to free fall speed, or the charring could have come from exposure to fire during the explosion.
I'm glad the data was recovered. I think the shuttle crew would be pleased. It enhances the legacy of the mission.
It's time once again for me to bask in my fleeting moment of USENET glory, when for a few brief shining months 18 years ago, it seemed like half the world was using my Simpsons ASCII art for their signature file.
I've had my $2.56 check hanging on my wall for 19 years now. (for finding a mostly inconsequential omission in the letter Q in romanu.mf.)
Did *anyone* actually cash any of those checks? They are one of the truly great trophies in the computer science field.
Or perhaps whoever might be threatening him is threatening to sue him if he discloses the fact that he has been threatened.
It happens.
Question -- how is the conductivity of space elevator cable? Could you have the cable consist of two electrically insulated cables held together somehow, then supply electricity across them?
More importantly, buy the cd/tape/record USED, not new.
When you buy a new CD, you are putting money into the pockets of
the RIAA. When you buy a used CD, you put your money into the
pocket of whoever last bought the CD, and the RIAA doesn't get
a penny.
If you purchase only used CDs and DVDs, you will have achieved all three goals.
Plus, by increasing the demand for used movies, you will be increasing the
value of your own collection by growing the used digital media market, which
will benefit you when you have movies of your own you wish to sell.
Translation:
The SCO vs IBM assault (funded by Microsoft) is about to implode.
Therefore, Microsoft is poised to move on to their next strategy of
attacking free software.
Does anyone seriously doubt that there will be a day-zero crack of the new keys?
Back when I was a university system programmer, I had an officemate named Tim. One day, Tim was poking around and discovered that hundreds of computers all across campus were synchronizing their clocks to his desktop workstation. He quickly figured out why.
The naming standard for desktop machines was to take the employee's first name and concatinate it with the first letter of their last name. So my desktop machine was named "johns.cc.uic.edu". Tim's machine was named "time.cc.uic.edu" because his last name began with "E". (cc meaning a "computer center" machine.)
Apparently many many university departments and users poked around and discovered what was obviously an official time server and configured their computers to synchronize to Tim's desktop machine. Tim, of course, had set his computer's clock by the office clock and never given it a second thought.
Motion picture film has phenomonal resolution. There's a lot of argument about what the "effective resolution" of film is, but you're very, very wrong about how classic movies will look in consumer digital formats.
None of those movies were filmed with DVD in mind, or even with home viewing in mind.
Yes, they were filmed with *THEATRES* in mind, back in the days when theatre screens were gigantic. Back then, movies were filmed on extremely high resolution, fine grain film stock, and they filmed using arc lamps to provide the enormous amounts of light necessary to expose the ultra-high resolution film stock.
It's difficult to compare film resolution to video resolution because they are largely apples and oranges. If you do a google search, you'll find a lot of opinions in the 20-50 equivalent megapixel range. When motion picture studios render computer graphics for transfer to 35mm film, and want to avoid pixelation in the release prints, the images are rendered at 6K x 4K, or 24 megapixels per frame. This is also the resolution used when motion picture negatives are scanned for restoration.
Also, modern motion picture film has a 1000:1 contrast ratio. Older black and white film stocks used much more silver than today, and had an even higher contrast ratio.
The highest available HDTV resolution is 1920x1080, or 2 megapixels per frame, or 1/12th the effective resolution of motion picture film. It's not even close.
The negatives will surely have deteriorated over time
That would have been true 10 or 15 years ago. By now, most of the studios have recognized the value of their libraries, and a large number of classic movies have been restored. Ted Turner took a lot of heat for "colorizing" his motion picture holdings, but the first step he took on each movie was to pay for a complete, top-quality black and white film restoration/preservation of the best existing preprint material.
The amout of deterioration depends on how well the negatives were processed and stored. Technicolor dye transfer prints do not fade, and if a studio has one in mint condition, it can provide a perfect color record. (George Lucas lucked out in that Star Wars was printed by Technicolor in Britain using the old dye-transfer process, so a few prints have survived with perfect, unfaded color. This allowed him to complete a near-perfect restoration of the film.)
Color films from the 50s to mid-80s filmed on Eastman negative film have problems with color fading (which can be corrected in most cases.) In the mid-80s Kodak improved their film stocks, and greatly reduced color fading. Restored movies don't have "spots [and] hairs on the film", because those are not on the camera negatives. When a movie is completed, the hand-spliced-together camera negative (which has been only ever handled in a clean room with cotton gloves) is used to make a small number of high-resolution interpositives. Then the camera negative goes into a film can and into a climate controlled vault.
Those interpositives are used to make a larger number of internegatives, which are then used to print all of the release prints that are sent to theatres and gather the "spots and hairs" that you are referring to. If, for some reason, the camera negatives are overused, and become dirty and scratched, the dirt and debris can be cleaned off, and scratches on the film are eliminated by "wet-gate" printing, where the film is wetted with a liquid just prior to scanning that makes the scratches disappear. You are seriously underestimating the motion picture restoration industry. Given enough money, virtually any motion picture, in any condition can be made to look like new *in the theatre.*
In short, wait and see. Old movies are going to look fantastic when scanned for HDTV. And the best news is that they are going to look even better for about the next 5 generations of consumer video media.
No consumer video system has even come close to the image resolution of motion picture film, and HDTV is no exception.
Lyrics that made no real sense worked for Van Halen with David Lee Roth
Heh. When I was in high school one of my favorite lyrics from "current" rock was from "Jump".
"Well can't you see me standing here I've got my back against the wrecking machine"
Then I found out years later that the lyric was actually "record machine" and it killed the song for me. I had a mental image of Roth standing up to this apocolyptic robot of death, back against the wall, when he was actually just a dork hanging out in front of the jukebox. Sheesh.
Yeah. What do you have to say about black musicians like Ray Charles who often made top-selling albums of songs that happened to be written by white songwriters?
For instance, Modern Sounds in Country and Western Music contains a top-ten selling cover of "You Don't Know Me", originally recorded by Eddy Arnold. Eddy Arnold was managed by Col. Tom Parker, who would go on to become Elvis Presley's manager.
So was Ray ripping off whitey? Or did he, like Elvis, recognize what was brilliant in someone else's work and reinterpret it to make it his own?
Gads I hope not. Take a look at this 1999 article for a reality check about the reliability of rockets:
I'd much rather have nuclear waste travelling down railroad tracks or in highway convoys than to regularly launch the practical equivalent of a maximum-damage "dirty bomb" and effectively roll the dice again and again, hoping that none ever blow up over Florida or the ocean or fail to reach orbit and burn up in the atmosphere.
Putting nuclear waste in rockets would probably be just about the most irresponsible thing you could do with it short of flying around and dumping it out of planes or shovelling it into incinerators.
As of a few years ago, I was a system administrator at a university. One of the more esoteric things I did was to bring ECAP over to VM/CMS.
ECAP (Engineering Circuit Analysis Program) was written around 1965 by IBM. I never used it (other than to port it and test it), but I believe that it basically solved simultaneous differential equations.
The interesting thing was that all that we had was a binary originally written for and compiled on an IBM 1620 computer. At some point, a 1620 emulator was written for OS/360, allowing the original binary to run on the IBM 360 architecture. It was running as an MVS loadlib. I moved the binary to VM/CMS, and it ran perfectly fine in OS emulation mode.
So, we have the 1620 binary (in the form of a virtual punch card deck)
running under a 1620 emulator
running under an MVS emulation library
running in VM/CMS on an IBM 3090
in a virtual machine, emulating an IBM 370.
All for an old professor whose tenure probably predated the 1620 computer that the software originally ran on.
Remember when terraserver.com first came out and it was the coolest site of the day because it had an incredibly huge one terabyte database?
What a difference six years makes.
There are ways around the carnival booth problem. It all depends on what you do with the information.
Just as an example, if the CAPPS data were used for the sole purpose of assigning air marshals to flagged flights:
o It would not interfere with the random-search system and reduce those odds. Thus, a CAPPS system would be at least as efficient as a non-CAPPS system in detecting contraband.
o It would not enable the carnival booth algorithm, because there would be no feedback mechanism for those individuals "scouting out"
the system.
o It would not harass innocent passengers. If an innocent passenger falsely trips the alert criteria for whatever reason, and there are air marshals anonymously monitoring him or her for the entire flight, the passenger will never know that they had been singled out and monitored. A far cry from being harassed every time you fly, or having to fight an airline "ban."
Using the CAPPS II tool to pull people out of line and search them or tell them that they won't be allowed to fly would be just plain stupid. The purpose is to catch terrorists, not to harass them and tip them off during their recon. missions.
Since RMS coined the term "free software", there has been talk about the semantic problems inherit in the term "free software." I've thought for a long time that RMS made a basic mistake when he coined the term "free software." The term has problems. I want to discuss two in particular.
First off, in the English language, the adjective "free", when paired with an inanimate noun, means free of charge. It does in every other context. If I say that I got a "free toaster", then you will assume that I meant that I didn't pay anything for it, not that the toaster comes with special rights. So the very term for the movement is equally open to deliberate misrepresentation, and simple misunderstanding. If you want a meme to become widespread, but it can't be understood without a semantic interpretation, then you have a problem.
The second problem is that "free" is not really an attribute of the software. Free software is "free" because of a choice by the copyright holder.
So why not "freed software" instead.
This term would solve both problems. On the one hand, it would extinguish the erroneous interpretation that the software is merely "free of charge", because the word "freed" is never used in that context. At the very least, someone who never heard that term would wonder (and perhaps ask) what it specifically meant, instead of immediately reaching the erroneous conclusion (which works against the movement) that "free software" is about zero-cost or public domain software, based on the way the word "free" is used as an adjective in the rest of the English language.
On the other hand, it correctly attributes the action of making software into "freed software" to the author/copyright holder. Freeing someone is considered to be a noble gesture. An act not just of giving, but of elevating he whom is freed. A freed slave becomes a freedman. I truly believe that the act of releasing software under the GPL is a noble gesture. It is an act of giving to the community. The term "freed software" would refocus the emphasis from the software to the programmer. And that's a good thing. What we need now isn't more free software. We need more people to make the transition from keeping their software proprietary to releasing their work as freed software.
I also believe that a great deal of the success of the term "open source" is because it is semantically correct -- the opposite of open source is closed source. That's something that people intuitively understand. I'm wondering if a careful redefinition of the free software movement as the "freed software movement" would have the same effect for RMS's ideals and goals.
Comments and criticisms welcomed.
On Soviet Russian space station, the vacuum and radiation study YOU!
The presence or absence of a scholarly degree on the part of a theorist says absolutely nothing about the merits of a theory. Nor does the amount of money invested in the enterprise of realizing the theory. I learned that one from cold fusion.
The site doesn't actually run through the numbers or mention how long this recovery time would be. The logic does make sense -- if the tether becomes slanted relative to the surface of the earth (my objection), then by definition there is a lateral component to the centripetal force on the tether, which should allow the sky station to steal some angular momentum from the earth. at some unspecified rate.
The site doesn't actually run through the numbers or mention how long this recovery time would be. If any physics mavens are irritated enough by my parent post to actually run the numbers, I'd be genuinely interested in seeing the solution worked out.
There is one problem that doesn't seem to be addressed -- the problem of imparting the necessary angular momentum to the elevator car as it rises.
As the car rises, from the point of view of the ground, it will appear that the car is dragging the tether westward. As the car continues to rise, the angle of the tether-bend will increase, pulling the base station down into a lower orbit, If the system doesn't "crack the whip" and snap off the sky station, or induce a huge oscillation in the tether/sky station, it will at the very least leave the sky station in a lower orbit, and the tether "slanted" westward. The more mass you send up the tether, the sharper the slant, and the worse the problem becomes.
The following experiment graphically illustrates the basic problem. The "space elevator" does not behave like an elevator.
Take a long piece of string or fishing line and tie a medium bolt to the end. Go outside to a large open area. Take a second bolt of similar size, thread it through the line, and hold it in your hand along with the free end of the fishing line. Now start spinning in a circle and let the line play out until the bolt is spinning at the end of the line. For the purposes of this demonstration, you are the earth, the fishing line is the elevator, and the tied bolt is the space anchor. You are looking straight "up" the elevator tether at the space station at the "top". Notice how your hand (the base station on the surface of the earth) is moving fairly slowly (with respect to your torso, the core of the earth), but the bolt at the end of the line (sky station) is whipping around at high speed? This means that the bolt on the end of the string has a lot of angular momentum, and the bolt in your hand has considerably less angular momentum. Now let go of the bolt you are holding while you continue to hold the string. The "elevator car" bolt will proceed to travel "up" the string into space until it comes to a stop at the "space station." However, the bolt will NOT simply rise straight up the line like an elevator car. Instead it will drag the line in the direction opposite to the direction you are rotating, and will "crack the whip" somewhere near the end of the travel. When you are all finished, the line will be oscillating "east to west" (forward/backward) relative to your hand.
Not what you may have been expecting based on the conceptually flawed "elevator" analogy.
Now there are limits to this demonstration. For instance, the actual elevator car will be speed controlled, not flying freely like the travelling bolt, and there are massive differences in scale and speed. But even if you solved all the engineering problems you can, the basic problem of conservation of angular momentum remains, and it's a show-stopper.
The oscillation problem could theoretically be avoided by carefully timing the rise of the elevator car, but the killer is conservation of angular momentum. As the elevator approaches the sky station, it will drag the tether westward and pull the sky station into a lower orbit. It can't help but do it, because as the elevator car reaches the sky station, it is going to have to match speed with the sky station. In order to do this, it will have to "steal" some angular momentum from the sky station, and even in a best-case scenario, where the timing is done absolutely perfectly and no oscillation is induced, the system will balance the equation by dropping the sky station into a lower orbit, and leaving the tether "slanted" westward. Bringing the elevator car back down again (perfectly timed once again to avoid oscillation) would straighten out the tether, but if the purpose of the space elevator is to sling things into space, then it becomes clear that the entire scheme isn't going to work. Any object lifted to the sky station is going to "steal" angular momentum from the sky station, and once you let go of anything, you will never get back that angular momentum, and there will be no way to straighten out the t