As a result, we're organising a demonstration next Tuesday in Brussels.
That's appearantly next Thursday, not Tuesday. Thursday the 17th of February, 2005. Mentioned just in case someone who won't be attending still wants to know...
Or you could compare it to the two-party system, where two parties together have more than 50 percent of the votes, rendering any other parties irrelevant.
So where websites before simply declared themselves as optimized for IE and left users to deal with that, Gartner now encourages webmasters to optimize for two browsers, and use JavaScript to find out which set of optimized pages to deliver? I'm sure Lynx users will be thrilled to be told that their browser is neither IE nor Firefox, and that the police has been called to investigate.
And just imagine when Gartner eventually declares it will be a three-browser world, what a paradigm shift. Somebody ought to define a browser-independent document format...
I don't know what the spacecraft looked like, but I recall it carried Beagle 2 to Mars as well. Deployment of the radar booms was to take place after releasing Beagle 2. It could very well be that Beagle 2 prevented the tests you suggest, or at least would have made them very expensive. They could have designed the spacecraft to allow for mechanical deployment tests even with Beagle 2 in place, but then how would you know those test results would be relevant to the situation in Mars orbit?
Anything can be tested in advance, except your ability to test things you didn't think of testing in advance. In hindsight, everybody else is stupid.
I read somewhere that any manned mission costs around ten times as much as a robotic one for the same target. That means you could send ten robotic ones for the price of one human mission. Each probe maybe won't be as capable as the human mission, but they make up for that by redundancy. If you send ten robotic probes and half of them fail, you still have five successful probes. If half a human mission fails, you don't have a single mission left. And even if it doesn't fail, it can't go to ten different locations simultaneously.
With better robotics, the human/robot cost ratio is likely to become more pronounced, not less. The human body isn't likely to adapt to the vacuum of space within the next few million years, and humans would still rely on robots to babysit their life support systems for them.
Humans may come in handy to do important things robots cannot yet do very well, but their primary motivation appears to be fame, the planting of a flag in a worthless desert on a planet far, far away.
"First foot on Mars!" - "Yeah, big deal. But robots took the first footage."
It wouldn't, at least not in any noticeable way. With a diameter of merely 300 meters, it should be around 50 trillion times (5*10^13) less massive than the Earth. When it moves 12,500 km (the Earth's diameter) in one direction, the Earth is moved a quarter of a micron in the other. It's basically a pretty small mountain in orbit, and it influences the Earth about as much as it's influenced itself by a small pebble, half an inch wide.
Or, we could say, "Space Shuttle, meet a grain of sand. It may dent your surface, but it will not change your orbit!"
A sometimes common perception among Slashdotters is that the law is immutable and easily defeated by technology, but a look at how the law has changed over the past several hundred years shows that the law does eventually catch up. It's my understanding that interstate transport can now include e-mail as well as the historic methods of postal mail and, as you've mentioned, cars.
The law (either the statutory text or its interpretation) is amended to deal with new realities, that's true, but it doesn't happen automatically. Some laws are widened in scope, others are not, in either case because of a reason. If not, totally different laws might end up applying to the very same circumstances, leading to mutually contradictory rulings. How come electronic publishing has been subject to the "interstate transfer of stolen goods" rule long before it's covered by freedom of the press statutes? The AOL database case isn't about publishing, but many other cases of electronic information transfer (such as the E911 case) are.
After having establisheded different legal frameworks surrounding different things like postal mail, telephone services, newspaper publishing, broadcast radio and television, banking, trade, private property, workplace environment, healthcare, public administration, law enforcement, education, scientific research, innovation, and national security, it shouldn't come as a major surprise that having all those laws apply to said activities when taking place within the same piece of machinery on your desktop may become a little messy if not done with proper consideration.
I would agree with you, but look at how the court argued in United States vs Riggs back in 1990 (yes, the famous E911 BellSouth document case) about applying the "interstate transfer of stolen goods" rule to an electronic file. When the issue of tangibility was brought up, the court briefly compared the electronic file with "a colorless, odorless, and tasteless gas", arguing that the "interstate transfer" rule could reasonably be applied to the gas in spite of its "intangibility". Now, even an odorless gas does consist of very tangible atoms, and it seems to me like a rather weak argument for applying the law also to what is essentially a transmission of information. If a TV station broadcasts a movie without paying royalties, is that "interstate transfer of stolen goods" too?
In the E911 case, the "value" of the stolen document was heavily inflated, quoted as $79,499 when a paper copy was actually available from Bellcore for $13.
There are actually two pieces of intangible property involved here. One is the original work as such, the database that may have cost a lot of time and money to compile. The other is an electronic copy of said original, perhaps available for a modest fee. I believe that in both the E911 case and this AOL case, only the copies have been transferred. The difference is that copies of the E911 document was available for sale, while the AOL customer database appearantly wasn't. How do you determine the "value" of something that isn't legally available for sale? Are we talking black market prices with respect to the copy (what someone is prepared to pay for it) here, or estimated damages to the database owner caused by the misappropriation of the information in it?
When a copy of a printed book is stolen, the value is considered to be the retail price for the copy (and that copy is quite tangible). No license fee for a reprint or damages for copyright infringement is ever involved. If an original manuscript is stolen, that is quite a different thing. But if you make an unauthorized copy (on paper) of an unpublished manuscript?
I'm unable to find this issue on the JURI agenda. Am I looking at the wrong agenda, or was the Rule 55 restart issue added too late for it to be listed?
I don't doubt that the decision was taken in proper order, but with all that talk about fishy last-minute changes to council agendas, you may think that JURI would know to be a little more prepared. Maybe these agendas on the Web are all written several months in advance, meaning we shouldn't expect last-minute changes to appear on-line..?
It seemed to me that this started out as an extortion racket, hoping that IBM would just cough up and pay. They didn't, and now IBM is striking back by bleeding them: they have far more resources to continue this than SCO has.
Besides seemingly growing into a mother-of-all-lawsuits kind of apocalyptic event (complete with horsemen and angels), it also reminds me of the Duckburg statue fight...
It would likely be better for the Linux community to code around the suspect areas rather than have this cloud hanging over everybody. SCO is holding us hostage via lack of specifics, not so much software code itself.
There is no cloud hanging over everybody, unless we trust SCO when they tell us there is a cloud (while not letting us know exactly where it is). It's not our job to force them to finish their sentences; it's up to them to either speak or not speak. As long as they don't state their accusations in plain language, there is no accusation, and we can go about our business as usual.
If we were to "code around" anything on our mere suspicion that someone, somewhere may think it's not 100 percent legit, then we would be held hostage via lack of specifics, and it would only serve to encourage others acting just like SCO (merely hint at a problem, and everybody will bend over backwards to "solve" it for you). What if blackmailing were that easy? Put in a newspaper ad saying that "fires happen" and everybody starts offering you money?
Only when they drag me personally into court will I care to even answer their questions, and my answer will be no, my software does not infringe on the rights of anybody, and nobody has made that accusation before. Next question?
How about Tycho? Just think of the view with an 85,000 meter mirror.
Part of the idea with a polar crater is to protect the instrument from temperature variations, something you would get a lot of on a monthly basis with a mirror anywhere else on the Moon. Tycho sits in sunlight for two weeks, then in darkness for two weeks. That's not a stable environment.
Also, a telescope made with a liquid mirror can be aimed in one direction only, towards zenith. Even the slow, monthly rotation of the Moon wouldn't allow for significant exposure times without motion blur, something you don't want when photographing distant galaxies spanning less than an arc second in the sky. The celestial poles are the only two spots in the sky that don't move around (they merely rotate), allowing for arbitrarily long exposures (the article suggests a year) using a camera synchronized with the sky.
If Celestia has the correct orientation of the Moon, the lunar axis points at constellation Draco in the northern hemisphere and at constellation Dorado in the south, the latter including the Large Magellanic Cloud. However, I don't know what particular deep sky objects would be visible using a telescope such as the proposed one at either pole.
Actually if you read the license agreenent, it does say that it doesn't try to verify the illegality of the media files it spots.
License agreement? Do you mean parents have to agree to the terms of a license in order to use the tool provided to them by the MPAA? Are they charging money for it too?
Maybe next they will start suing people for downloading copies of their anti-piracy software from unauthorized websites... As I don't do Flash, is there a direct link I could use?
The Voyager probes are no longer in the plane of the planetary orbit; I believe both of them are now travelling in a direction more than 30 degrees from this plane.
This is correct. As seen from Earth, the JPL Solar System Simulator shows Voyager 1 in Ophiuchus, Voyager 2 in Telescopium, Pioneer 10 in Taurus, and Pioneer 11 in Scutum. Of these, only Pioneer 10 remains really close to the ecliptic (within 5 degrees), while Pioneer 11 deviates maybe 15 degrees from it. The Voyager probes are each some 30-40 degrees off, on different sides of the ecliptic.
It doesn't say anything about an elliptical orbit around the SUN.
Ah. The thought of actually checking with the article momentarily struck my mind, but as every other poster was busy discussing gravity assists and how this project compared to the Pioneer and Voyager missions, the notion that you could place such a probe in Earth orbit seemed just too bizarre... Thanks for the clarification. I see adeyadey has arrived at the same conclusion below.
Now I wonder, will that satellite cross Moon orbit, maybe even use the Moon for gravity assist flybys?
And it's tough to use planetary slingshots when you're going out perpendicular to the ecliptic.
I suppose you could plan your final planetary slingshot to go either north or south of the planet, rather than near its orbital plane, thereby ending up with a trajectory aimed quite far from the ecliptic. I think at least one of the Pioneer/Voyager probes did something like that.
The article merely says that IBEX is to be placed in a highly elliptical orbit around the Sun, but offers no quantitative details. How far out is it meant to go? If beyond Pluto at 40 AU, its average distance to the Sun will be at least 20 AU, resulting in an orbital period of around 90 years (much like comet Halley with 76 years). I think that's a long-term science commitment. The Pioneer and Voyager probes were able to get out there faster because they are on non-return trajectories (hyperbolic, I suppose).
Do they plan to defy Kepler's laws and speed up the trip by using either gravity assist from the major planets or onboard propulsion? In either case, I wouldn't call the resulting trajectory an "orbit" in itself, but quite substantial deviations from one. Will the IBEX probe survive long enough to cross the heliopause more than once?
I mean, think about it--both the data and the dopler effect are going to show up as variations in the frequency of the carrier wave (or, if you prefer, in a change in the amplitude of the signals received at frequencies near the nominal carrier frequency).
Huygens is designed to generate telemetry at a rate of 8192 bits per second. Using a common modulation technique known as binary phase-shift keying, Huygens's transmission system represents 1s and 0s by varying the phase of the outgoing carrier wave. Recovering these bits requires precise timing: in simple terms, Cassini's receiver is designed to break the incoming signal into 8192 chunks every second. It determines the phase of each chunk compared with an unmodulated wave and outputs a 0 or a 1 accordingly [see chart, "
Going Through a Phase"].
I would assume that detecting the signal at all means they can also detect its phase, regardless of how weak it is; it should merely require comparing it with an unmodulated signal generated at the receiving end. I don't know what carrier frequency they used, but I suppose precise timing in the nanosecond range is necessary, as we are literally dealing with the speed of light here.
Or, was Huygens transmitting an entirely different signal to Earth merely for this interferometry experiment? I doubt it, but various comments regarding this event seem to point in that direction. In particular, the analogy ESA officials made with the dialling tone you hear when you pick up a phone handset would make more sense then, as neither the dialling tone contains any data.
IBM's 500 out of 40000 patents is a good start, and the fact they are open to anyone doing open source is right where the spirit of open source remains fixed.
The number of patents opened up doesn't mean a lot, nor does the true intentions of either company. The fact that the existance of software patents as such stifle innovation is a more pressing problem. What the FOSS community needs is freedom from patent restrictions imposed by law, not generous license grants to use patents currently held by these companies. Every software developer still risks violating some other patent than those explicitely made available.
IBM's (or Sun's) generosity towards open source developers is good PR, but it also helps preserving a flawed patent regime by taking away your best arguments against it. If a major movie studio were to declare that it will no longer take legal action against those who download movies over the Internet, would you consider that "a good start" towards amending the DMCA?
If I had the money, I'd try to patent the most obvious and common programming techniques possible, and then prohibit everybody from using those, until the law had to be changed. Saying "I, the inventor of the wheel as well as the alphabet, hereby grant you an irrevocable, transferrable, royalty-free license to make wheels and write books" will lead us nowhere.
Well just think what happens if one day the asteroid named after you decides to pay Earth an intimate visit.
I suppose that's why, according to IAU guidelines, objects "that approach or cross Earth's orbit are given mythological names". When we eventually learn that the End of the World is near, we don't want it to arrive by the name of Einstein, Zappa, or the Marshmallow Man. It better be named after Zuul or some other forgotten deity.
If they didn't find out there was a problem until after failing to receive channel A data from the orbiter, then the radio waves from the probe would have already passed the Earth also.
They learned that there was a problem when the Cassini relay transmission came in loud and clear at ESA, but with Channel B data only. At that time there would have been no point in enabling the Channel A receiver, as Cassini had already lost contact with Huygens.
The radio telescopes listened to the signal from Huygens directly, bypassing the Cassini relay (and therefore hearing the signal several hours earlier). They had planned to pick up the carrier wave anyway for doppler measurements, and have recorded the raw, analog signal for analysis. Now that half of the experiment was lost, they will have to cut to the point of the landing using a single scissor blade only. Try it with a piece of paper and one hand behind your back; it ain't easy (poor analogy, I know).
One-way light (and radio signal) travel time from Cassini to Earth is about 68 minutes. The Huygens transmission was some 4 hours long, but I don't know whether the recording was speeded up by Cassini when relaying it to Earth (it was supposedly relayed multiple times).
No, I don't work on the project, but a team at my university designed and built one of the instruments onboard Cassini (a Langmuir probe, measuring space plasma characteristics).
Ah, I now realize this is exactly what interferometry is about, detecting the same signal with multiple receivers and seeing how they differ in doppler shift. Even the Earth doesn't provide that much of an angle as seen from Titan, so I admit it would be an achievement if they managed to reconstruct the path based on the data they got.
Still, I guess the ability to measure such slight differences in doppler shift would depend more on the sensitivity of the receivers, than on computational power. They do need storage facilities for huge volumes of analog recordings though, capturing nanosecond discrepancies or whatever in the wave...
I thought they were planning to use the radio telescopes for this (reconstructing the path of the probe) long before they learned that the Channel A receiver wasn't going to be operational. Or, what was that Very Long Baseline Interferometry experiment meant for? Merely detecting the presence of a signal?
I suppose that one advantage of doing the same measurements via two receivers (one on Earth, the other on Cassini) would be the ability to reconstruct the path in two dimensions, thereby learning not only how fast the probe travelled, but in what direction (sideways or down).
I guess most of that computational effort may be to properly extract the true signal from all the other noise they probably recorded, much like the SETI@Home project does in a distributed fashion. However, no amount of computation can properly compensate for the loss of a receiver listening from a different position, if that's indeed what the receiver onboard Cassini was meant to do. Even if they had a dozen radio telescopes on Earth listening simultaneously, they would all detect the same doppler shift, telling them essentially nothing but the speed of Huygens relative to Earth only. As it was close to mid-day where Huygens landed on Titan, the Sun (and Earth) were close to zenith, and we would primarily be measuring descent speed, not lateral speed.
Has anybody seen a scientific explanation of the details of the doppler wind experiment, such as what measurements the Channel A receiver was supposed to perform and how it would deliver its results to Earth? I'm pretty sure three hours of analog recording of a high-frequency carrier wave would constitute way too much raw data to transmit to Earth for later analysis, so I assume some processing must be performed already onboard Cassini. If so, performing the same process for the signal received directly via the radio telescopes shouldn't take considerably longer time, once it has been properly extracted from the noise.
The Commission is appointed by the national head of states
As certain European countries are constitutional monarchies, where the head of state isn't elected but descends from a royal lineage, having them jointly appoint the Commission certainly wouldn't be democratic. To be precise, the Commission as a whole is actually approved by the EU parliament, and individual commissioners are nominated by their respective governments, which may or may not in turn be influenced by the position of their heads of state, depending on their national constitutions.
Other than that, you are quite correct. Even if there is a considerable democratic "distance" between the Commission and the voters of Europe, it ultimately does derive its power from duly elected representatives, either in national governments or (to a lesser extent) in the European parliament.
"The invention based upon the fact that when a body made of magnetisable material is touched at different points and at different times by an electromagnet included in a telephonic or telegraphic circuit, its parts are subject to such varied magnetic influences that conversely by the action of the magnetisable body upon the electromagnet the same sounds or signals are subsequently given out in the telephone or recording instrument as those which previously caused the magnetic action upon the magnetisable body."
This isn't about digital storage, but rather analog storage. Poulsen apparently didn't consider representing audio (or any other kind of information) as discrete digits (in binary or any other base), which would be required for a digital system.
However, I think Joseph Jacquard deserves mention for his use of "punched cards" to store instructions for an automatic weaving loom, 200 years ago. Actually, even the written alphabet, which evolved out of arbitrary pictograms into a finite set of symbols several thousand years ago, could be described as a method for digital information storage, as the semantics of a written word normally doesn't change with the exact visual appearance of each glyph. I wonder if King Hammurabi ever awarded someone a patent on writing?
You simply simulate the special conditions when things are supposed to happen.
Simulation was also used by Boris Smeds for his elaborate testing of the Huygens-Cassini communications link in 2000. While he were to test the actual receivers on Cassini, he used the Huygens copy left on Earth to generate and record a sample data stream in the proper format. He then simulated the effects of Huygens descending along an irregular path, taking atmospheric interference into account, by carefully tweaking both the frequency and the power of the Deep Space Network transmitter used for the test. When Cassini returned perfectly clear garbage instead of the expected test data, he reworked his experiment until it became clear that Doppler shift was a major problem to Cassini.
That simulation covered only a specific component of the Cassini-Huygens mission, and I'm not sure the exact command sequence sent to Cassini in preparation for the landing had even been written at that time, so nobody may have been able to test it in a complete simulator of the entire system. Since the mission schedule was altered to deal with the Doppler shift problem, the command sequence would probably have required modification anyway, but the more you can simulate in advance, the better.
Rather than spend extra time writing a simulator from scratch, wouldn't it be better if the design process included simulation by default? I'm not familiar with how these systems are designed, but I suppose you could integrate simulation parameters with the technical documentation. Ideally, you should be able to execute the documentation and have the whole system begin operating virtually on your screen. Manual checklists are necessary as well, but you shouldn't have to rely on a checklist to make sure that all the different software components (and maybe even some in hardware) will cooperate nicely.
As the Channel A failure wasn't due to some unexpected natural phenomenon, but rather a glitch in the program, it would most likely have been detected by simulation. If a human is supposed to press a particular button at a particular time, you can simulate that too, or even find out what happens if the operator has gone fishing.
Slashdot Mirror
That's appearantly next Thursday, not Tuesday. Thursday the 17th of February, 2005. Mentioned just in case someone who won't be attending still wants to know...
Or you could compare it to the two-party system, where two parties together have more than 50 percent of the votes, rendering any other parties irrelevant.
So where websites before simply declared themselves as optimized for IE and left users to deal with that, Gartner now encourages webmasters to optimize for two browsers, and use JavaScript to find out which set of optimized pages to deliver? I'm sure Lynx users will be thrilled to be told that their browser is neither IE nor Firefox, and that the police has been called to investigate.
And just imagine when Gartner eventually declares it will be a three-browser world, what a paradigm shift. Somebody ought to define a browser-independent document format...
I don't know what the spacecraft looked like, but I recall it carried Beagle 2 to Mars as well. Deployment of the radar booms was to take place after releasing Beagle 2. It could very well be that Beagle 2 prevented the tests you suggest, or at least would have made them very expensive. They could have designed the spacecraft to allow for mechanical deployment tests even with Beagle 2 in place, but then how would you know those test results would be relevant to the situation in Mars orbit?
Anything can be tested in advance, except your ability to test things you didn't think of testing in advance. In hindsight, everybody else is stupid.
I read somewhere that any manned mission costs around ten times as much as a robotic one for the same target. That means you could send ten robotic ones for the price of one human mission. Each probe maybe won't be as capable as the human mission, but they make up for that by redundancy. If you send ten robotic probes and half of them fail, you still have five successful probes. If half a human mission fails, you don't have a single mission left. And even if it doesn't fail, it can't go to ten different locations simultaneously.
With better robotics, the human/robot cost ratio is likely to become more pronounced, not less. The human body isn't likely to adapt to the vacuum of space within the next few million years, and humans would still rely on robots to babysit their life support systems for them.
Humans may come in handy to do important things robots cannot yet do very well, but their primary motivation appears to be fame, the planting of a flag in a worthless desert on a planet far, far away.
"First foot on Mars!" - "Yeah, big deal. But robots took the first footage."
It wouldn't, at least not in any noticeable way. With a diameter of merely 300 meters, it should be around 50 trillion times (5*10^13) less massive than the Earth. When it moves 12,500 km (the Earth's diameter) in one direction, the Earth is moved a quarter of a micron in the other. It's basically a pretty small mountain in orbit, and it influences the Earth about as much as it's influenced itself by a small pebble, half an inch wide.
Or, we could say, "Space Shuttle, meet a grain of sand. It may dent your surface, but it will not change your orbit!"
The law (either the statutory text or its interpretation) is amended to deal with new realities, that's true, but it doesn't happen automatically. Some laws are widened in scope, others are not, in either case because of a reason. If not, totally different laws might end up applying to the very same circumstances, leading to mutually contradictory rulings. How come electronic publishing has been subject to the "interstate transfer of stolen goods" rule long before it's covered by freedom of the press statutes? The AOL database case isn't about publishing, but many other cases of electronic information transfer (such as the E911 case) are.
After having establisheded different legal frameworks surrounding different things like postal mail, telephone services, newspaper publishing, broadcast radio and television, banking, trade, private property, workplace environment, healthcare, public administration, law enforcement, education, scientific research, innovation, and national security, it shouldn't come as a major surprise that having all those laws apply to said activities when taking place within the same piece of machinery on your desktop may become a little messy if not done with proper consideration.
I would agree with you, but look at how the court argued in United States vs Riggs back in 1990 (yes, the famous E911 BellSouth document case) about applying the "interstate transfer of stolen goods" rule to an electronic file. When the issue of tangibility was brought up, the court briefly compared the electronic file with "a colorless, odorless, and tasteless gas", arguing that the "interstate transfer" rule could reasonably be applied to the gas in spite of its "intangibility". Now, even an odorless gas does consist of very tangible atoms, and it seems to me like a rather weak argument for applying the law also to what is essentially a transmission of information. If a TV station broadcasts a movie without paying royalties, is that "interstate transfer of stolen goods" too?
In the E911 case, the "value" of the stolen document was heavily inflated, quoted as $79,499 when a paper copy was actually available from Bellcore for $13.
There are actually two pieces of intangible property involved here. One is the original work as such, the database that may have cost a lot of time and money to compile. The other is an electronic copy of said original, perhaps available for a modest fee. I believe that in both the E911 case and this AOL case, only the copies have been transferred. The difference is that copies of the E911 document was available for sale, while the AOL customer database appearantly wasn't. How do you determine the "value" of something that isn't legally available for sale? Are we talking black market prices with respect to the copy (what someone is prepared to pay for it) here, or estimated damages to the database owner caused by the misappropriation of the information in it?
When a copy of a printed book is stolen, the value is considered to be the retail price for the copy (and that copy is quite tangible). No license fee for a reprint or damages for copyright infringement is ever involved. If an original manuscript is stolen, that is quite a different thing. But if you make an unauthorized copy (on paper) of an unpublished manuscript?
I'm unable to find this issue on the JURI agenda. Am I looking at the wrong agenda, or was the Rule 55 restart issue added too late for it to be listed?
I don't doubt that the decision was taken in proper order, but with all that talk about fishy last-minute changes to council agendas, you may think that JURI would know to be a little more prepared. Maybe these agendas on the Web are all written several months in advance, meaning we shouldn't expect last-minute changes to appear on-line..?
Besides seemingly growing into a mother-of-all-lawsuits kind of apocalyptic event (complete with horsemen and angels), it also reminds me of the Duckburg statue fight...
There is no cloud hanging over everybody, unless we trust SCO when they tell us there is a cloud (while not letting us know exactly where it is). It's not our job to force them to finish their sentences; it's up to them to either speak or not speak. As long as they don't state their accusations in plain language, there is no accusation, and we can go about our business as usual.
If we were to "code around" anything on our mere suspicion that someone, somewhere may think it's not 100 percent legit, then we would be held hostage via lack of specifics, and it would only serve to encourage others acting just like SCO (merely hint at a problem, and everybody will bend over backwards to "solve" it for you). What if blackmailing were that easy? Put in a newspaper ad saying that "fires happen" and everybody starts offering you money?
Only when they drag me personally into court will I care to even answer their questions, and my answer will be no, my software does not infringe on the rights of anybody, and nobody has made that accusation before. Next question?
Part of the idea with a polar crater is to protect the instrument from temperature variations, something you would get a lot of on a monthly basis with a mirror anywhere else on the Moon. Tycho sits in sunlight for two weeks, then in darkness for two weeks. That's not a stable environment.
Also, a telescope made with a liquid mirror can be aimed in one direction only, towards zenith. Even the slow, monthly rotation of the Moon wouldn't allow for significant exposure times without motion blur, something you don't want when photographing distant galaxies spanning less than an arc second in the sky. The celestial poles are the only two spots in the sky that don't move around (they merely rotate), allowing for arbitrarily long exposures (the article suggests a year) using a camera synchronized with the sky.
If Celestia has the correct orientation of the Moon, the lunar axis points at constellation Draco in the northern hemisphere and at constellation Dorado in the south, the latter including the Large Magellanic Cloud. However, I don't know what particular deep sky objects would be visible using a telescope such as the proposed one at either pole.
License agreement? Do you mean parents have to agree to the terms of a license in order to use the tool provided to them by the MPAA? Are they charging money for it too?
Maybe next they will start suing people for downloading copies of their anti-piracy software from unauthorized websites... As I don't do Flash, is there a direct link I could use?
This is correct. As seen from Earth, the JPL Solar System Simulator shows Voyager 1 in Ophiuchus, Voyager 2 in Telescopium, Pioneer 10 in Taurus, and Pioneer 11 in Scutum. Of these, only Pioneer 10 remains really close to the ecliptic (within 5 degrees), while Pioneer 11 deviates maybe 15 degrees from it. The Voyager probes are each some 30-40 degrees off, on different sides of the ecliptic.
Ah. The thought of actually checking with the article momentarily struck my mind, but as every other poster was busy discussing gravity assists and how this project compared to the Pioneer and Voyager missions, the notion that you could place such a probe in Earth orbit seemed just too bizarre... Thanks for the clarification. I see adeyadey has arrived at the same conclusion below.
Now I wonder, will that satellite cross Moon orbit, maybe even use the Moon for gravity assist flybys?
I suppose you could plan your final planetary slingshot to go either north or south of the planet, rather than near its orbital plane, thereby ending up with a trajectory aimed quite far from the ecliptic. I think at least one of the Pioneer/Voyager probes did something like that.
The article merely says that IBEX is to be placed in a highly elliptical orbit around the Sun, but offers no quantitative details. How far out is it meant to go? If beyond Pluto at 40 AU, its average distance to the Sun will be at least 20 AU, resulting in an orbital period of around 90 years (much like comet Halley with 76 years). I think that's a long-term science commitment. The Pioneer and Voyager probes were able to get out there faster because they are on non-return trajectories (hyperbolic, I suppose).
Do they plan to defy Kepler's laws and speed up the trip by using either gravity assist from the major planets or onboard propulsion? In either case, I wouldn't call the resulting trajectory an "orbit" in itself, but quite substantial deviations from one. Will the IBEX probe survive long enough to cross the heliopause more than once?
I find it a little confusing too, but as described in last year's IEEE Spectrum article on the Cassini relay doppler shift problem, the radio link from Huygens used neither frequency nor amplitude modulation, but rather phase modulation:
I would assume that detecting the signal at all means they can also detect its phase, regardless of how weak it is; it should merely require comparing it with an unmodulated signal generated at the receiving end. I don't know what carrier frequency they used, but I suppose precise timing in the nanosecond range is necessary, as we are literally dealing with the speed of light here.
Or, was Huygens transmitting an entirely different signal to Earth merely for this interferometry experiment? I doubt it, but various comments regarding this event seem to point in that direction. In particular, the analogy ESA officials made with the dialling tone you hear when you pick up a phone handset would make more sense then, as neither the dialling tone contains any data.
The number of patents opened up doesn't mean a lot, nor does the true intentions of either company. The fact that the existance of software patents as such stifle innovation is a more pressing problem. What the FOSS community needs is freedom from patent restrictions imposed by law, not generous license grants to use patents currently held by these companies. Every software developer still risks violating some other patent than those explicitely made available.
IBM's (or Sun's) generosity towards open source developers is good PR, but it also helps preserving a flawed patent regime by taking away your best arguments against it. If a major movie studio were to declare that it will no longer take legal action against those who download movies over the Internet, would you consider that "a good start" towards amending the DMCA?
If I had the money, I'd try to patent the most obvious and common programming techniques possible, and then prohibit everybody from using those, until the law had to be changed. Saying "I, the inventor of the wheel as well as the alphabet, hereby grant you an irrevocable, transferrable, royalty-free license to make wheels and write books" will lead us nowhere.
I suppose that's why, according to IAU guidelines, objects "that approach or cross Earth's orbit are given mythological names". When we eventually learn that the End of the World is near, we don't want it to arrive by the name of Einstein, Zappa, or the Marshmallow Man. It better be named after Zuul or some other forgotten deity.
They learned that there was a problem when the Cassini relay transmission came in loud and clear at ESA, but with Channel B data only. At that time there would have been no point in enabling the Channel A receiver, as Cassini had already lost contact with Huygens.
The radio telescopes listened to the signal from Huygens directly, bypassing the Cassini relay (and therefore hearing the signal several hours earlier). They had planned to pick up the carrier wave anyway for doppler measurements, and have recorded the raw, analog signal for analysis. Now that half of the experiment was lost, they will have to cut to the point of the landing using a single scissor blade only. Try it with a piece of paper and one hand behind your back; it ain't easy (poor analogy, I know).
One-way light (and radio signal) travel time from Cassini to Earth is about 68 minutes. The Huygens transmission was some 4 hours long, but I don't know whether the recording was speeded up by Cassini when relaying it to Earth (it was supposedly relayed multiple times).
No, I don't work on the project, but a team at my university designed and built one of the instruments onboard Cassini (a Langmuir probe, measuring space plasma characteristics).
Ah, I now realize this is exactly what interferometry is about, detecting the same signal with multiple receivers and seeing how they differ in doppler shift. Even the Earth doesn't provide that much of an angle as seen from Titan, so I admit it would be an achievement if they managed to reconstruct the path based on the data they got.
Still, I guess the ability to measure such slight differences in doppler shift would depend more on the sensitivity of the receivers, than on computational power. They do need storage facilities for huge volumes of analog recordings though, capturing nanosecond discrepancies or whatever in the wave...
I thought they were planning to use the radio telescopes for this (reconstructing the path of the probe) long before they learned that the Channel A receiver wasn't going to be operational. Or, what was that Very Long Baseline Interferometry experiment meant for? Merely detecting the presence of a signal?
I suppose that one advantage of doing the same measurements via two receivers (one on Earth, the other on Cassini) would be the ability to reconstruct the path in two dimensions, thereby learning not only how fast the probe travelled, but in what direction (sideways or down).
I guess most of that computational effort may be to properly extract the true signal from all the other noise they probably recorded, much like the SETI@Home project does in a distributed fashion. However, no amount of computation can properly compensate for the loss of a receiver listening from a different position, if that's indeed what the receiver onboard Cassini was meant to do. Even if they had a dozen radio telescopes on Earth listening simultaneously, they would all detect the same doppler shift, telling them essentially nothing but the speed of Huygens relative to Earth only. As it was close to mid-day where Huygens landed on Titan, the Sun (and Earth) were close to zenith, and we would primarily be measuring descent speed, not lateral speed.
Has anybody seen a scientific explanation of the details of the doppler wind experiment, such as what measurements the Channel A receiver was supposed to perform and how it would deliver its results to Earth? I'm pretty sure three hours of analog recording of a high-frequency carrier wave would constitute way too much raw data to transmit to Earth for later analysis, so I assume some processing must be performed already onboard Cassini. If so, performing the same process for the signal received directly via the radio telescopes shouldn't take considerably longer time, once it has been properly extracted from the noise.
As certain European countries are constitutional monarchies, where the head of state isn't elected but descends from a royal lineage, having them jointly appoint the Commission certainly wouldn't be democratic. To be precise, the Commission as a whole is actually approved by the EU parliament, and individual commissioners are nominated by their respective governments, which may or may not in turn be influenced by the position of their heads of state, depending on their national constitutions.
Other than that, you are quite correct. Even if there is a considerable democratic "distance" between the Commission and the voters of Europe, it ultimately does derive its power from duly elected representatives, either in national governments or (to a lesser extent) in the European parliament.
From the patent description:
This isn't about digital storage, but rather analog storage. Poulsen apparently didn't consider representing audio (or any other kind of information) as discrete digits (in binary or any other base), which would be required for a digital system.However, I think Joseph Jacquard deserves mention for his use of "punched cards" to store instructions for an automatic weaving loom, 200 years ago. Actually, even the written alphabet, which evolved out of arbitrary pictograms into a finite set of symbols several thousand years ago, could be described as a method for digital information storage, as the semantics of a written word normally doesn't change with the exact visual appearance of each glyph. I wonder if King Hammurabi ever awarded someone a patent on writing?
Simulation was also used by Boris Smeds for his elaborate testing of the Huygens-Cassini communications link in 2000. While he were to test the actual receivers on Cassini, he used the Huygens copy left on Earth to generate and record a sample data stream in the proper format. He then simulated the effects of Huygens descending along an irregular path, taking atmospheric interference into account, by carefully tweaking both the frequency and the power of the Deep Space Network transmitter used for the test. When Cassini returned perfectly clear garbage instead of the expected test data, he reworked his experiment until it became clear that Doppler shift was a major problem to Cassini.
That simulation covered only a specific component of the Cassini-Huygens mission, and I'm not sure the exact command sequence sent to Cassini in preparation for the landing had even been written at that time, so nobody may have been able to test it in a complete simulator of the entire system. Since the mission schedule was altered to deal with the Doppler shift problem, the command sequence would probably have required modification anyway, but the more you can simulate in advance, the better.
Rather than spend extra time writing a simulator from scratch, wouldn't it be better if the design process included simulation by default? I'm not familiar with how these systems are designed, but I suppose you could integrate simulation parameters with the technical documentation. Ideally, you should be able to execute the documentation and have the whole system begin operating virtually on your screen. Manual checklists are necessary as well, but you shouldn't have to rely on a checklist to make sure that all the different software components (and maybe even some in hardware) will cooperate nicely.
As the Channel A failure wasn't due to some unexpected natural phenomenon, but rather a glitch in the program, it would most likely have been detected by simulation. If a human is supposed to press a particular button at a particular time, you can simulate that too, or even find out what happens if the operator has gone fishing.