actually while true HD is very good (1920 x 1080) it still does not have the color space and contrast that the black chip TI projectors have (as well as a slightly lower resolution)l. Also note that there are temporal artifacts introduced by the conversion between the 24 frames per second progressive the movie was presumably shot at and the 30 frames per second interlaced of the 1920x1080 HD standard. It lacks that subjective "film" feel that is, admittedly, actually a lower quality image. As for the 1280x720 60fps standard not only is that of significantly lower res. but it has that very different "showscan" (an old movie format) feel due to the high frame rate.
All these points will need to be re-examined in one to two years when the new 4K projectors start coming out with much higher (even than film in true comparisons) resolutions.
DRM is just one of the technical issues. The DCI specification includes transport, subtitling (via XML), compression, watermarking, multiple audio/language tracks and of course encryption. By the way, the encryption isn't just on the hard drive/fiber/satellite. It extends all the way to between the server and the projector so that a professional "hacker" can't decrypt the bit stream between the two. I understand it goes just about all the way to the imaging chip.
the real problem is that the studios are the ones who will profit from digital cinema (because they won't have to make prints or ship them) whereas the theater owners will be the ones spending the money for the equipment. That is why the studios are trying to come up with ways where they will foot the bill. Also the economics of the industry will change because since second run prints need no longer be sent to secondary markets, films can be released in one giant global release. (This is why DVDs have region encoding, to prevent the DVD release in one country from interfering with the theatrical release in another.)
While the chances of hearing from alien worlds is depressing small ("Rare Earth"), still the thought that a few private individuals will know first should give us pause. If there is more information in the detected signal than "hello there", who knows what could be learned? Markets may move in a big way (here's how antigravity works, immortality, existence of god, a big black hole is headed your way, etc.).
Then again if that's the only way we're gonna get these projects funded, perhaps these philanthropists should be rewarded for their risk taking.
"subject Defendants to liability with respect to injunctive and declaratory relief, but also for nominal damages and the reasonable value of Plaintiffs' attorneys' services and costs incurred in vindicating Plaintiffs' constitutional rights." PAGE 138 OF THE DECISION
Nothing like money to change people's behavior. If you don't think the "nominal damages" are likely to be significant, as someone who has had a few battles in the courtroom myself, "the attorneys' services and costs incurred" (like discovery) can be very significant.
I swear I thought I put in something that the basic idea of a tether has been thought of many times before going back to a Russian visionary around the turn of the century. What is new here is to use the energy of rotation to change the objects orbital path. I'm sorry if anyone thought I was trying to get credit for any part of the "space elevator" idea.
I had to make an addendum. In case the rotational scheme will not produce enough delta V, the energy generated by the tether could drive some of the other schemes (ion drives, mass drivers) in a more cost efficient manner than solar panels or nuclear reactors.
I don't care who uses my idea as long as it gets used. (If I'm not too lazy I'll submit a proposal anyway but I think this idea shoud be submitted by whoever can write the best proposal.)
Novel method for changing orbit of small planetary body (asteroid/comet).
Abstract: Using a tethered "sling" to release pieces of a small planetary body, an small (inexpensive) payload delivered to a body rotating at a sufficient rate can effectively convert its rotational energy into directed kinetic energy. Tether, which may be attached to said body via cables or netting, can also generate power for its own operations, obviating a need for a large power source. Since only a small fraction of the mass is to released at any one time, problems such as excessive accelration, breakup of body etc. will be avoided. This has numerous applications in asteroid/comet defense, asteroid mining etc.
Main text: Previous proposals for changing the orbital path of a small planetary body have included delivering an explosive charge to said body (typically nuclear) for impact on or near it, moving the body directly through the use of ion drives or mass accelerators or even gravitional attraction by a sufficiently large spacecraft. These ideas unfortantely suffer from various problems such as possibility of fracturing said body or high costs due to large spacecraft or energy sources being sent over interplanetary distances. Still the consequences of a major impact or dire enough so to warrant the consideration of these ideas.
My idea, which I am releasing into the public domain, would be to convert the rotational energy of the small planetary body into directed kinetic energy sufficient to "push" the body on a different orbital path. If done early enough (years? decades?) this small diversion could prevent the body from impacting the earth. The advantage to using my scheme would be that the spacecraft sent to the object could be reasonably small although it would require a mechanism for securely attaching a long (kilometers?) tether to the asteroid via cables or, in the case of a very fragmented body, a large net. The cable would be conducting and may even be self extending using static charges. Small robots would be used for both moving material up and down the cable as well as mining the body for material to be cast into space.
The main design consideration would be the length of the tether (or possibly tower), it must extend beyond the "geo"-sync distance defined by the rotational speed of the body and its gravitational attraction. For some objects no doubt this would require a tether to be impractically long, however recent probes have determined that many(?) bodies rotate fast enough for a tether to be of practical length. ("Practical length" is in reference to NASA experiments in LEO where tethers were extended or attempted to be extended distance of up to tens of kilometers). (Another major impediment would be if the body were tumbling, possibly in a chaotic fashion. I do not know if a tether/tower could be constructed in that scenario). The tether would have a few other important characteristics. It should allow for small robots to travel up and down its length by means of a gripping mechanism (preferably simultaneously on two "sides") and should be conducting. This would allow for the robots to both receive power for their "climb" and to generate power once they've passed the "geo"-sync height. The tether would be kept taught by means of a counterweight placed beyond the "geo"-sync height, presumably at the end of the tether.
The implementation of the system would possibly be as follows. A spacecraft would enter into orbit at the "geo"-sync location around the body. It would then lower the tether to the body while at the same time extending a tether in the opposite direction, keeping the spacecraft at the center of gravity. Once the tether has reached the surface, a robot(s) would climb down and then securely fasten the end. It, or other robot(s) would then breaking up pieces of
the reason why they sell you two "eye" balls...
on
Throwable WiFi Camera
·
· Score: 1
... is to get stereo! (just kidding but wouldn't it be nice for distance measurements etc.).
I'm posting this here for attribution, just in case in 20 (or 50 or 200) years from now someone rediscovers this idea. Then they'll use the archives to discover that the idea used to save the world was originally conceived by me! (and boost my Karma score into the ionosphere!).
Basically one of the big problems of moving an asteroid is its rotation. Trying to move a big spinning object, is really hard. There is a tremendous amount of energy contained in the spin so fighting it will be very expensive.
So don't fight it, USE it. Lower a long rope to the surface of the asteroid letting the spin of the asteroid keep it taught. (same idea as a space elevator). Now ferry rocks way beyond the "Geosync" point, if the rotation is anything substantial it shouldn't be too far from the surface (a few tens of kilometers, no need for carbon nanotubes). Release the rocks into space, timing the release so that they shoot off in the same general direction.
What you're doing is converting the enormous rotational energy of the asteroid into kinetic energy of the rocks. Depending on how long your rope is (and thus how fast your rocks are released) you are going to get a substantial thrust in the opposite direction. (for every action there is a reaction). You are also making the asteroid smaller. As for the released rocks, while they may someday in the distant future hit the earth they'll be small and won't make it past the upper atmosphere.
Of course in addition to the long time frame (given) that this will take; this assumes that the asteroid is rotating (probably won't have to be too fast) and that you can attach the cable to some point on the asteroid. I believe most asteroids we've discovered have a substantial rotation, this is probably due to the violent manner in which they were formed and subsequently battered. As for the cable attachment, some nets and cables stretching around the asteroid should handle this just fine.
So there you have it. Instead of launching a huge expensive power hungry spacecraft that'll provide an absolutely tiny acceleration, you could send a relatively tiny spacecraft consisting of a few solar powered low mass robots (to move the rocks to the cable) and some sort of conveyor mechanism. While this'll take some engineering, it certainly is less than trying to have a 20 ton spacecraft do precision (because gravity is inverse squared you need to be close) station keeping off a tumbling (maybe chaotically!) asteroid for decades. If the rotation rate is high enough, you could even use the asteroid to generate energy (microwave beaming?).
In Los Angeles, there are two additional reasons for getting a high MPG vehicle. First you can drive in the carpool lane with only one passenger and secondly you can park anywhere in the city of Los Angeles without feeding the meter.
If you live here you'll know those two benefits are worth a lot.
Of course some people will say that these are perks that come at everyone else's expense. True but these cars are BENEFITING everyone else in several ways that ordinary cars don't. For example by cutting down on oil imports they reduce our exposure to the middle east and all that implies*. Secondly cutting down on greenhouse gasses benefit everyone not just the drivers.
I believe economists call these "externalities" and the city of Los Angeles and the state of California have sought to encourage the purchase of these vehicles for the PUBLIC benefits that they bring.
* There was a study done where it claimed if everyone drove on of these vehicles instead of their current cars, we wouldn't have ANY oil imports (or maybe just those from the middle east).
Sorry to repost this but...
We need to find out whether or not it is solid rock (or iron!) or a pile of rubble! SO SEND DEEP IMPACT (URL:http://www.nasa.gov/mission_pages/deepimpact/ main/index.html)
It is currently scheduled for a Jan. 12th launch to some random comet, why not use it to determine the makeup of this asteroid instead? Of course this might delay the launch a few(?) months but that is a much shorter delay than building a new impactor probe etc.
This assumes that the Delta rocket has enough delta V to get to this asteroid rather than the comet. After checking the orbital plots it looks like it gets close to the earth every year!
We need to find out whether or not it is solid rock (or iron!) or a pile of rubble! SO SEND DEEP IMPACT (URL:http://www.nasa.gov/mission_pages/deepimpact/ main/index.html)
It is currently scheduled for a Jan. 12th launch to some random comet, why not use it to determine the makeup of this asteroid instead? Of course this might delay the launch a few(?) months but that is a much shorter delay than building a new impactor probe etc.
This assumes that the Delta rocket has enough delta V to get to this asteroid rather than the comet. My only comment is that since this is an earth orbit crossing asteroid there may be some opportunities in the near future!
First I looked at the graphics provided on this web page URL:http://neo.jpl.nasa.gov/news/news146.html. Note how in the animation the asteroid seems to hit at the time when the moon is almost directly in line with the sun.
Then I ran the solar system simulator URL:http://space.jpl.nasa.gov/ to see what face of the planet will be pointing towards the sun and moon at this time. It appears as if the western hemisphere is spared.
Of course this is horribly imprecise but it brings up a question: if the asteroid is going to hit BUT NOT THE USA will the USA bother to mount an effort to stop it?
By the way, this is a repost of an earlier post (1 of 2 of mine). Please take a look under the Ben Affleck joke near the beginning. I also suggest redirecting the Direct Impact probe (launch date Jan. 12) so that we use it to determine the composition of the asteroid (and not the random comet it is currently targeting).
Finally, I'm not sure it would be a good idea to be directly opposite the globe from the impact site. The seismic shock waves may come to a focus there with some unpleasant results. (I think impact craters on some of the moons circling jupiter and saturn have shown this).
First I looked at the graphics provided on this web page URL:http://neo.jpl.nasa.gov/news/news146.html. Note how in the animation the asteroid seems to hit at the time when the moon is almost directly in line with the sun. Then I ran the solar system simulator URL:http://space.jpl.nasa.gov/ to see what face of the planet will be pointing towards the sun and moon at this time. It appears as if the western hemisphere is spared.
Of course this is horribly imprecise but it brings up a question: if the asteroid is going to hit BUT NOT THE USA will the USA bother to mount an effort to stop it?
By the way, this is a repost of an earlier post (1 of 2 of mine). Please take a look under the Ben Affleck joke. I also suggest redirecting the Direct Impact probe on Jan. 12 so that we use that to determine the composition of the asteroid.
Sorry to respond to my own post but I figured the slashdot audience might find this interesting.
First I looked at the graphics provided on this web page URL:http://neo.jpl.nasa.gov/news/news146.html. Note how in the animation the asteroid seems to hit at the time when the moon is almost directly in line with the sun. Then I ran the solar system simulator URL:http://space.jpl.nasa.gov/ to see what face of the planet will be pointing towards the sun and moon at this time. It appears as if the western hemisphere is spared.
Of course this is horribly imprecise but it brings up a question: if the asteroid is going to hit BUT NOT THE USA will the USA bother to mount an effort to stop it?
Before we start trying to destroy the asteroid with a "bomb" shouldn't we find out exactly what its made of? It will make a huge difference to how we respond (do we try to knock it off course with a nuke or gently push it with a mass driver/ion drive/solar sail) dependign on whether it is a big ball of iron, a loose pile of rubble (or even a mass of hollywood film critics).
Since we have a probe designed to do exactly that sitting on a launch pad for a January 12, 2005 launch why not use it on this potential threat rather than planned comet? Wouldn't it be much wiser to redirect Direct Impact (URL:http://www.nasa.gov/mission_pages/deepimpact/ main/index.html) even if it means a delay of a few(?) months while we calculate and find the best launch window? I'm assuming the delta V is achievable since the asteroid seems to be in an earth orbit crossing orbit.
With a 1/62 chance of hitting earth and a Torino rating (now) of 4 I'd much rather use our probe on this potential threat than to determine the composition of some random comet! 25 years may seem like a long time but the longer we wait the harder it is to push this "flying mountain" out of harms way.
As an answer to this and other posts, the pusher satellite which is in orbit around the earth may BENEFIT from the force it is imparting to the probe. Since it is (presumably in an equatorial orbit) circling the earth, half the time a force directed "out" (away from the sun for example) would slow the satellite causing it to de-orbit but half the time it would actually lift the satellite by imparting momentum in the direction of orbital motion. Of course if the satellite was in polar orbit or sun-synchronous orbit the there would be no effect because the force would be perpendicular to the orbital plane.
As for decceleration around the target body (Mars), if the body is large enough (deep enough gravity well), the probe could be slingshotted back facing earth. In that case it will be facing the pusher beam which can deccelerate it. (This idea is from interstellar solar sail designs). Honestly though, unless the plasma beam can be kept very tight over interplanetary distances(!) I can't see how a reasonable amount of thrust could be generated for this to work. Aerobraking (see "2010") would probably be much more practical.
As pointed out elsewhere the energy needs are likely to be very high and only a nuclear reactor (not just radioisotopes) could generate it. Presumably these needs could be taken care of by NASA's "Prometheus" program which is developing nuclear reactors for energy hungry missions (like JIMO). On the other hand, I'm not sure if the energy needs to accelerate a probe are THAT high, remember that you are only accelerating the probe (and not its fuel!) which is a much smaller mass than you might think. Manned missions are much heavier though.
actually at a special presentation which I was fortunate enough to attend, Gweneth Paltrow and Jude Law said that the lack of sets "freed" them in their acting. The fact that they had an animatic of the entire film that they used as reference before every take allowed them to "hit their marks" more easily and allowed them to be more creative in their acting. It was like theater acting on a bare set.
As far as the audience reaction, this film was deliberately made in a stylized form. In fact they processed it in black and white and recolorized it to give an old movie feel! (They also didn't use the state of the art capture technology, just plain old Sony HD-CAM 1440x960, 3:1:1, 8bit). It is clear from many other recent motion pictures that they could have made it appear as realistic as they wanted but chose not to.
The main reason why it IS the future is because it is thought that it cost about 1/3 what it would have been if they had shot it on "real" sets! Hate to say it but saving more than $80 million dollars (estimated cost of the film $40M-$70M) would drive any producer to making his film this way, regardless of actor preference or (most) audience reactions.
Hi there-
Thanks for the suggestion. One of the specialists I saw also recommended it. I got it and put it in my refrigerator. I could never bring myself to using it, I was afraid that it would make everything very dark (isn't that what'll happen if your pupils are too small?). Call me chicken but since my condition is manageable (I can drive, carefully) I decided I could put up with that (so much for having the night sky with stars resolved to points of light).
thanks for the info! I will definitely consider this in my post-operative treatments! Is this laser technology recent? I focused (pun intended) more on the physician than the equipment, I was afraid more about human error (think unsteady hands!).
of course I knew about the possible side effects. it was the PROBABILITY of them happening that was not explained to me as being anything other than very low. True enough, I did not know to research that piece of the puzzle. Then again after researching the doctor, his certification, his institute, his track record, and the technology I did not think I would have to research the research articles. Isn't that what the AMA and FDA is for, to keep us all from having to be doctors? You would assume that for an optional procedure like this, the probability of adverse side effects would be very low. NOW I'm learning that it is not. (Isn't the hippocratic oath "first do no harm?").
You can crash in an airplane accident or you can crash flying the space shuttle. Unless you know the probability both seem equally safe. Which one would you choose to put precious cargo on when either way will give you the same result?
On the other hand, if your wife knew that it "was likely to happen" that her "night vision was likely to suck" and still went under the laser perhaps her research skills are great but her judgement needs rethinking. For everyone else who may not wiish to take that kind of risk for something that can be easily and safely corrected with glasses or contacts I repeat: DON'T DO IT!
I got Lasik eye surgery in both my eyes from one of the most respected (and expensive) surgeons on the west coast. I did my homework, at the time 4 years ago, he had already done 10,000+ procedures. He has impeccable credentials (Harvard M.D.) and I believe he was one of the people who actually developed the technology. He is the founder of a very fancy institute and did numerous tests both before and after the procedure.
Anyway the reason why I mention this is because although things went perfectly, there was one bad consequence. I HAVE BLURRY VISION IN LOW LIGHT! I understand this is because, when you have as bad eyesight as I did, when the pupil expands in low light it goes beyond the area where the laser ablation took place. The consequence of having light going into your eye from the central focused region and the outer unfocused region is blurriness typically as halos or rings.
During the day/bright light my vision is absolutely perfect, I have better than 20/20 whereas before I had something like 600/20. Unfortunately my work takes me into lots of dark rooms looking at relatively dimly lit images and judging them for image quality/artifacts. So it was BAD!
As a consequence I am keeping up with technological developments waiting for a fix. Now they are using something called wavefront technology, I guess they are able to ablate away your cornea in fractions of a wavelength of visible light (the laser is UV to prevent heating which would kill underlying cells). Unfortunately I think this does not help me because I need the laser to be able to get a larger region of my cornea so that my expanded pupils don't reach the boundary of the ablated area.
I am not sure if my problems were due to my extremely nearsighted vision or other factors. In any case, I am posting this warning that even the best doctor may leave you with BAD results. (I have my complaints that this part of the industry seems to be poorly regulated, while I was given disclosures on the procedures, I do not think the odds of poor results were clearly explained to me. So if this doctor thinks I'm defaming him, I'll be happy to take him to court.).
Slashdot Mirror
actually while true HD is very good (1920 x 1080) it still does not have the color space and contrast that the black chip TI projectors have (as well as a slightly lower resolution)l. Also note that there are temporal artifacts introduced by the conversion between the 24 frames per second progressive the movie was presumably shot at and the 30 frames per second interlaced of the 1920x1080 HD standard. It lacks that subjective "film" feel that is, admittedly, actually a lower quality image. As for the 1280x720 60fps standard not only is that of significantly lower res. but it has that very different "showscan" (an old movie format) feel due to the high frame rate.
All these points will need to be re-examined in one to two years when the new 4K projectors start coming out with much higher (even than film in true comparisons) resolutions.
DRM is just one of the technical issues. The DCI specification includes transport, subtitling (via XML), compression, watermarking, multiple audio/language tracks and of course encryption. By the way, the encryption isn't just on the hard drive/fiber/satellite. It extends all the way to between the server and the projector so that a professional "hacker" can't decrypt the bit stream between the two. I understand it goes just about all the way to the imaging chip.
the real problem is that the studios are the ones who will profit from digital cinema (because they won't have to make prints or ship them) whereas the theater owners will be the ones spending the money for the equipment. That is why the studios are trying to come up with ways where they will foot the bill. Also the economics of the industry will change because since second run prints need no longer be sent to secondary markets, films can be released in one giant global release. (This is why DVDs have region encoding, to prevent the DVD release in one country from interfering with the theatrical release in another.)
While the chances of hearing from alien worlds is depressing small ("Rare Earth"), still the thought that a few private individuals will know first should give us pause. If there is more information in the detected signal than "hello there", who knows what could be learned? Markets may move in a big way (here's how antigravity works, immortality, existence of god, a big black hole is headed your way, etc.).
Then again if that's the only way we're gonna get these projects funded, perhaps these philanthropists should be rewarded for their risk taking.
"subject Defendants to liability with respect to injunctive and declaratory relief, but also for nominal damages and the reasonable value of Plaintiffs' attorneys' services and costs incurred in vindicating Plaintiffs' constitutional rights." PAGE 138 OF THE DECISION
Nothing like money to change people's behavior. If you don't think the "nominal damages" are likely to be significant, as someone who has had a few battles in the courtroom myself, "the attorneys' services and costs incurred" (like discovery) can be very significant.
I swear I thought I put in something that the basic idea of a tether has been thought of many times before going back to a Russian visionary around the turn of the century. What is new here is to use the energy of rotation to change the objects orbital path. I'm sorry if anyone thought I was trying to get credit for any part of the "space elevator" idea.
;)
That is if anyone is reading this.
I had to make an addendum. In case the rotational scheme will not produce enough delta V, the energy generated by the tether could drive some of the other schemes (ion drives, mass drivers) in a more cost efficient manner than solar panels or nuclear reactors.
I don't care who uses my idea as long as it gets used. (If I'm not too lazy I'll submit a proposal anyway but I think this idea shoud be submitted by whoever can write the best proposal.)
Novel method for changing orbit of small planetary body (asteroid/comet).
Abstract: Using a tethered "sling" to release pieces of a small planetary body, an small (inexpensive) payload delivered to a body rotating at a sufficient rate can effectively convert its rotational energy into directed kinetic energy. Tether, which may be attached to said body via cables or netting, can also generate power for its own operations, obviating a need for a large power source. Since only a small fraction of the mass is to released at any one time, problems such as excessive accelration, breakup of body etc. will be avoided. This has numerous applications in asteroid/comet defense, asteroid mining etc.
Main text: Previous proposals for changing the orbital path of a small planetary body have included delivering an explosive charge to said body (typically nuclear) for impact on or near it, moving the body directly through the use of ion drives or mass accelerators or even gravitional attraction by a sufficiently large spacecraft. These ideas unfortantely suffer from various problems such as possibility of fracturing said body or high costs due to large spacecraft or energy sources being sent over interplanetary distances. Still the consequences of a major impact or dire enough so to warrant the consideration of these ideas.
My idea, which I am releasing into the public domain, would be to convert the rotational energy of the small planetary body into directed kinetic energy sufficient to "push" the body on a different orbital path. If done early enough (years? decades?) this small diversion could prevent the body from impacting the earth. The advantage to using my scheme would be that the spacecraft sent to the object could be reasonably small although it would require a mechanism for securely attaching a long (kilometers?) tether to the asteroid via cables or, in the case of a very fragmented body, a large net. The cable would be conducting and may even be self extending using static charges. Small robots would be used for both moving material up and down the cable as well as mining the body for material to be cast into space.
The main design consideration would be the length of the tether (or possibly tower), it must extend beyond the "geo"-sync distance defined by the rotational speed of the body and its gravitational attraction. For some objects no doubt this would require a tether to be impractically long, however recent probes have determined that many(?) bodies rotate fast enough for a tether to be of practical length. ("Practical length" is in reference to NASA experiments in LEO where tethers were extended or attempted to be extended distance of up to tens of kilometers). (Another major impediment would be if the body were tumbling, possibly in a chaotic fashion. I do not know if a tether/tower could be constructed in that scenario). The tether would have a few other important characteristics. It should allow for small robots to travel up and down its length by means of a gripping mechanism (preferably simultaneously on two "sides") and should be conducting. This would allow for the robots to both receive power for their "climb" and to generate power once they've passed the "geo"-sync height. The tether would be kept taught by means of a counterweight placed beyond the "geo"-sync height, presumably at the end of the tether.
The implementation of the system would possibly be as follows. A spacecraft would enter into orbit at the "geo"-sync location around the body. It would then lower the tether to the body while at the same time extending a tether in the opposite direction, keeping the spacecraft at the center of gravity. Once the tether has reached the surface, a robot(s) would climb down and then securely fasten the end. It, or other robot(s) would then breaking up pieces of
... is to get stereo! (just kidding but wouldn't it be nice for distance measurements etc.).
I'm posting this here for attribution, just in case in 20 (or 50 or 200) years from now someone rediscovers this idea. Then they'll use the archives to discover that the idea used to save the world was originally conceived by me! (and boost my Karma score into the ionosphere!).
Basically one of the big problems of moving an asteroid is its rotation. Trying to move a big spinning object, is really hard. There is a tremendous amount of energy contained in the spin so fighting it will be very expensive.
So don't fight it, USE it. Lower a long rope to the surface of the asteroid letting the spin of the asteroid keep it taught. (same idea as a space elevator). Now ferry rocks way beyond the "Geosync" point, if the rotation is anything substantial it shouldn't be too far from the surface (a few tens of kilometers, no need for carbon nanotubes). Release the rocks into space, timing the release so that they shoot off in the same general direction.
What you're doing is converting the enormous rotational energy of the asteroid into kinetic energy of the rocks. Depending on how long your rope is (and thus how fast your rocks are released) you are going to get a substantial thrust in the opposite direction. (for every action there is a reaction). You are also making the asteroid smaller. As for the released rocks, while they may someday in the distant future hit the earth they'll be small and won't make it past the upper atmosphere.
Of course in addition to the long time frame (given) that this will take; this assumes that the asteroid is rotating (probably won't have to be too fast) and that you can attach the cable to some point on the asteroid. I believe most asteroids we've discovered have a substantial rotation, this is probably due to the violent manner in which they were formed and subsequently battered. As for the cable attachment, some nets and cables stretching around the asteroid should handle this just fine.
So there you have it. Instead of launching a huge expensive power hungry spacecraft that'll provide an absolutely tiny acceleration, you could send a relatively tiny spacecraft consisting of a few solar powered low mass robots (to move the rocks to the cable) and some sort of conveyor mechanism. While this'll take some engineering, it certainly is less than trying to have a 20 ton spacecraft do precision (because gravity is inverse squared you need to be close) station keeping off a tumbling (maybe chaotically!) asteroid for decades. If the rotation rate is high enough, you could even use the asteroid to generate energy (microwave beaming?).
wisebabo
In Los Angeles, there are two additional reasons for getting a high MPG vehicle. First you can drive in the carpool lane with only one passenger and secondly you can park anywhere in the city of Los Angeles without feeding the meter.
If you live here you'll know those two benefits are worth a lot.
Of course some people will say that these are perks that come at everyone else's expense. True but these cars are BENEFITING everyone else in several ways that ordinary cars don't. For example by cutting down on oil imports they reduce our exposure to the middle east and all that implies*. Secondly cutting down on greenhouse gasses benefit everyone not just the drivers.
I believe economists call these "externalities" and the city of Los Angeles and the state of California have sought to encourage the purchase of these vehicles for the PUBLIC benefits that they bring.
* There was a study done where it claimed if everyone drove on of these vehicles instead of their current cars, we wouldn't have ANY oil imports (or maybe just those from the middle east).
nuff' said
Sorry to repost this but... We need to find out whether or not it is solid rock (or iron!) or a pile of rubble! SO SEND DEEP IMPACT (URL:http://www.nasa.gov/mission_pages/deepimpact/ main/index.html)
It is currently scheduled for a Jan. 12th launch to some random comet, why not use it to determine the makeup of this asteroid instead? Of course this might delay the launch a few(?) months but that is a much shorter delay than building a new impactor probe etc.
This assumes that the Delta rocket has enough delta V to get to this asteroid rather than the comet. After checking the orbital plots it looks like it gets close to the earth every year!
We need to find out whether or not it is solid rock (or iron!) or a pile of rubble! SO SEND DEEP IMPACT (URL:http://www.nasa.gov/mission_pages/deepimpact/ main/index.html)
It is currently scheduled for a Jan. 12th launch to some random comet, why not use it to determine the makeup of this asteroid instead? Of course this might delay the launch a few(?) months but that is a much shorter delay than building a new impactor probe etc.
This assumes that the Delta rocket has enough delta V to get to this asteroid rather than the comet. My only comment is that since this is an earth orbit crossing asteroid there may be some opportunities in the near future!
First I looked at the graphics provided on this web page URL:http://neo.jpl.nasa.gov/news/news146.html. Note how in the animation the asteroid seems to hit at the time when the moon is almost directly in line with the sun.
Then I ran the solar system simulator URL:http://space.jpl.nasa.gov/ to see what face of the planet will be pointing towards the sun and moon at this time. It appears as if the western hemisphere is spared.
Of course this is horribly imprecise but it brings up a question: if the asteroid is going to hit BUT NOT THE USA will the USA bother to mount an effort to stop it?
By the way, this is a repost of an earlier post (1 of 2 of mine). Please take a look under the Ben Affleck joke near the beginning. I also suggest redirecting the Direct Impact probe (launch date Jan. 12) so that we use it to determine the composition of the asteroid (and not the random comet it is currently targeting).
Finally, I'm not sure it would be a good idea to be directly opposite the globe from the impact site. The seismic shock waves may come to a focus there with some unpleasant results. (I think impact craters on some of the moons circling jupiter and saturn have shown this).
First I looked at the graphics provided on this web page URL:http://neo.jpl.nasa.gov/news/news146.html. Note how in the animation the asteroid seems to hit at the time when the moon is almost directly in line with the sun. Then I ran the solar system simulator URL:http://space.jpl.nasa.gov/ to see what face of the planet will be pointing towards the sun and moon at this time. It appears as if the western hemisphere is spared. Of course this is horribly imprecise but it brings up a question: if the asteroid is going to hit BUT NOT THE USA will the USA bother to mount an effort to stop it? By the way, this is a repost of an earlier post (1 of 2 of mine). Please take a look under the Ben Affleck joke. I also suggest redirecting the Direct Impact probe on Jan. 12 so that we use that to determine the composition of the asteroid.
Sorry to respond to my own post but I figured the slashdot audience might find this interesting.
First I looked at the graphics provided on this web page URL:http://neo.jpl.nasa.gov/news/news146.html. Note how in the animation the asteroid seems to hit at the time when the moon is almost directly in line with the sun. Then I ran the solar system simulator URL:http://space.jpl.nasa.gov/ to see what face of the planet will be pointing towards the sun and moon at this time. It appears as if the western hemisphere is spared.
Of course this is horribly imprecise but it brings up a question: if the asteroid is going to hit BUT NOT THE USA will the USA bother to mount an effort to stop it?
Before we start trying to destroy the asteroid with a "bomb" shouldn't we find out exactly what its made of? It will make a huge difference to how we respond (do we try to knock it off course with a nuke or gently push it with a mass driver/ion drive/solar sail) dependign on whether it is a big ball of iron, a loose pile of rubble (or even a mass of hollywood film critics).
/ main/index.html) even if it means a delay of a few(?) months while we calculate and find the best launch window? I'm assuming the delta V is achievable since the asteroid seems to be in an earth orbit crossing orbit.
Since we have a probe designed to do exactly that sitting on a launch pad for a January 12, 2005 launch why not use it on this potential threat rather than planned comet? Wouldn't it be much wiser to redirect Direct Impact (URL:http://www.nasa.gov/mission_pages/deepimpact
With a 1/62 chance of hitting earth and a Torino rating (now) of 4 I'd much rather use our probe on this potential threat than to determine the composition of some random comet! 25 years may seem like a long time but the longer we wait the harder it is to push this "flying mountain" out of harms way.
As an answer to this and other posts, the pusher satellite which is in orbit around the earth may BENEFIT from the force it is imparting to the probe. Since it is (presumably in an equatorial orbit) circling the earth, half the time a force directed "out" (away from the sun for example) would slow the satellite causing it to de-orbit but half the time it would actually lift the satellite by imparting momentum in the direction of orbital motion. Of course if the satellite was in polar orbit or sun-synchronous orbit the there would be no effect because the force would be perpendicular to the orbital plane.
As for decceleration around the target body (Mars), if the body is large enough (deep enough gravity well), the probe could be slingshotted back facing earth. In that case it will be facing the pusher beam which can deccelerate it. (This idea is from interstellar solar sail designs). Honestly though, unless the plasma beam can be kept very tight over interplanetary distances(!) I can't see how a reasonable amount of thrust could be generated for this to work. Aerobraking (see "2010") would probably be much more practical.
As pointed out elsewhere the energy needs are likely to be very high and only a nuclear reactor (not just radioisotopes) could generate it. Presumably these needs could be taken care of by NASA's "Prometheus" program which is developing nuclear reactors for energy hungry missions (like JIMO). On the other hand, I'm not sure if the energy needs to accelerate a probe are THAT high, remember that you are only accelerating the probe (and not its fuel!) which is a much smaller mass than you might think. Manned missions are much heavier though.
actually at a special presentation which I was fortunate enough to attend, Gweneth Paltrow and Jude Law said that the lack of sets "freed" them in their acting. The fact that they had an animatic of the entire film that they used as reference before every take allowed them to "hit their marks" more easily and allowed them to be more creative in their acting. It was like theater acting on a bare set.
As far as the audience reaction, this film was deliberately made in a stylized form. In fact they processed it in black and white and recolorized it to give an old movie feel! (They also didn't use the state of the art capture technology, just plain old Sony HD-CAM 1440x960, 3:1:1, 8bit). It is clear from many other recent motion pictures that they could have made it appear as realistic as they wanted but chose not to.
The main reason why it IS the future is because it is thought that it cost about 1/3 what it would have been if they had shot it on "real" sets! Hate to say it but saving more than $80 million dollars (estimated cost of the film $40M-$70M) would drive any producer to making his film this way, regardless of actor preference or (most) audience reactions.
Hi there- Thanks for the suggestion. One of the specialists I saw also recommended it. I got it and put it in my refrigerator. I could never bring myself to using it, I was afraid that it would make everything very dark (isn't that what'll happen if your pupils are too small?). Call me chicken but since my condition is manageable (I can drive, carefully) I decided I could put up with that (so much for having the night sky with stars resolved to points of light).
I knew something else was wrong! And don't even get me started on my X-ray vision!
thanks for the info! I will definitely consider this in my post-operative treatments! Is this laser technology recent? I focused (pun intended) more on the physician than the equipment, I was afraid more about human error (think unsteady hands!).
of course I knew about the possible side effects. it was the PROBABILITY of them happening that was not explained to me as being anything other than very low. True enough, I did not know to research that piece of the puzzle. Then again after researching the doctor, his certification, his institute, his track record, and the technology I did not think I would have to research the research articles. Isn't that what the AMA and FDA is for, to keep us all from having to be doctors? You would assume that for an optional procedure like this, the probability of adverse side effects would be very low. NOW I'm learning that it is not. (Isn't the hippocratic oath "first do no harm?").
You can crash in an airplane accident or you can crash flying the space shuttle. Unless you know the probability both seem equally safe. Which one would you choose to put precious cargo on when either way will give you the same result?
On the other hand, if your wife knew that it "was likely to happen" that her "night vision was likely to suck" and still went under the laser perhaps her research skills are great but her judgement needs rethinking. For everyone else who may not wiish to take that kind of risk for something that can be easily and safely corrected with glasses or contacts I repeat: DON'T DO IT!
Hi there-
I got Lasik eye surgery in both my eyes from one of the most respected (and expensive) surgeons on the west coast. I did my homework, at the time 4 years ago, he had already done 10,000+ procedures. He has impeccable credentials (Harvard M.D.) and I believe he was one of the people who actually developed the technology. He is the founder of a very fancy institute and did numerous tests both before and after the procedure.
Anyway the reason why I mention this is because although things went perfectly, there was one bad consequence. I HAVE BLURRY VISION IN LOW LIGHT! I understand this is because, when you have as bad eyesight as I did, when the pupil expands in low light it goes beyond the area where the laser ablation took place. The consequence of having light going into your eye from the central focused region and the outer unfocused region is blurriness typically as halos or rings.
During the day/bright light my vision is absolutely perfect, I have better than 20/20 whereas before I had something like 600/20. Unfortunately my work takes me into lots of dark rooms looking at relatively dimly lit images and judging them for image quality/artifacts. So it was BAD!
As a consequence I am keeping up with technological developments waiting for a fix. Now they are using something called wavefront technology, I guess they are able to ablate away your cornea in fractions of a wavelength of visible light (the laser is UV to prevent heating which would kill underlying cells). Unfortunately I think this does not help me because I need the laser to be able to get a larger region of my cornea so that my expanded pupils don't reach the boundary of the ablated area.
I am not sure if my problems were due to my extremely nearsighted vision or other factors. In any case, I am posting this warning that even the best doctor may leave you with BAD results. (I have my complaints that this part of the industry seems to be poorly regulated, while I was given disclosures on the procedures, I do not think the odds of poor results were clearly explained to me. So if this doctor thinks I'm defaming him, I'll be happy to take him to court.).
Good luck.