Satellites are classified by orbits, and orbital maneuvering, more than by anything else (assuming you don't have direct knowledge of their mission). Different satellites have different orbits for a reason, to support their mission, and their orbits thus provide information about their missions. GPS satellites are in high 12 hour orbits, comm sats are in even higher, 24 hour, orbits, weather satellites are in sun-synchronous polar orbits, etc.
An example : if you have an orbit that passes over Baghdad, big deal, they all will do that sooner or later. If you
have one that passes over Baghdad early to mid-morning, when the shadows are nice and long (generally regarded as the best time for surface photography), you may have something. If you have an object whose orbit is continually tweaked to keep passing over Baghdad during mid-morning every few days, and that also happens to be at the perigee of the orbit, then you almost certainly have something. If you look at where it passes over during later-afternoon on other orbits, you may start to gain insight into what other targets are of interest.
You can bet that every serious intelligence service on the planet does this. Amateurs have been doing it since the 1950's, so this is old, old news.
Um, they have found a lot of these (273 candidates this morning), and most of them are not in Solar System type... solar systems. That is indeed having a
profound effect on research into planet formation.
Apparently not, even at the BBC. What they were saying is that there could be hundreds of worlds in the solar system, not in the galaxy. (They meant in the Kuiper belt, far outside of Pluto and Neptune.)
We have already found 273 extra-solar planets in the galaxy. No one doubts now that there are millions, if not billions, in the galaxy, and a puling "hundreds" of Earth type planets in the galaxy would strike most people following this research as a very low estimate.
From the article : "Some astronomers believe there may be hundreds of small rocky bodies in the outer edges of our own Solar System, and perhaps even a handful of frozen Earth-sized worlds."
I would also regard this as almost not news at all, given the rapid rate of discovery of TNOs (Trans Neptunian Objects), three of which so far are the size of Pluto or larger.
I am old enough to remember reading AI predictions from the early 1960's (see the subject for this post). I think in general predictions from 20+ years ago underestimate developments in computer hardware and greatly overestimate developments in AI, so I see no reason not to predict that the same will hold for 20 year predictions from our time.
I happen to think that we do have a super-intelligence that greatly exceeds any human intelligence - it's called science, and it is and has for decades been a human-machine symbiosis. That will continue to become more effective as time passes, regardless of the state of machine consciousness.
Gee, then you miss your plane. I have missed many planes. It happens, even to the "get there 3 hours early" crowd. Unless it's Saigon, 1973, there will be another.
I posted a query to a Linux newsgroup, and a respondent told me that the solution was to open a command prompt and type "man find", which I am aware is a polite way of saying "screw you, newbie", but which I dutifully followed anyway and got an output screen of which the first paragraph was:
Just thought I might help him out. Sounds like he needs it.
A lot more information is available from the Renesys Blog.
It was both the Flag Telecom and SEA-ME-WEA 4 cables outside of Alexandria, Egypt. The SEA-ME-WEA 3 cable is apparently OK.
In long distance telecommunications, you really need another path going "the other way around" to be safe. For example, many of the large companies with back-offices in India pay for routes both over the Atlantic to the Middle East to India (which might have been broken by this) and also West Coast to Pacific to Singapore to India (which would not have been).
At AmericaFree.TV, the steady Egyptian audience went to zero yesterday, presumably because of the break, while the audience in Iran, Iraq, the GCC, Pakistan and India did not seem to be affected.
There have been no direct detections of gravitational waves so far. There have been indirect detections (most robustly with the various binary millisecond pulsars, whose orbits slowly decay due to their radiating energy away in gravitational waves), but no direct detections. However, this was not really seen as an issue, as gravitational wave searches before LIGO suffered from the problem that there were no known sources strong enough for them to detect with good probability. You have to start somewhere, and there is always the chance of either good luck, say a close supernova, or some unknown source that is stronger than expected, but I believe that this is the first actual event whose gravitational waves, by a reasonable model, had a chance of being detected with existing equipment. One such non-detection means nothing - maybe the Gamma Ray Burst occurred way behind the Andromeda Galaxy, for example. If this is consistently repeated, we will eventually conclude that there is something wrong with our physics or our astrophysics, but it is much too soon for that.
I have no idea what their vision is. Based on my experience, there literally may not be one. (NASA suffered greatly when all of the original space enthusiasts retired in the 1970's, as they were largely replaced by bureaucrats.) However, my vision (the only one I can really speak for) is to create sustainable human habitations in space.
Moving asteroids is not trivial. Asteroid densities are around a few grams / cm^3, so a 100 meter "diameter" asteroids (ones that small are highly unlikely to be spherical) will have a mass of maybe 10 Megatons (or 10^10 kg). Changing the velocity of that mass by 10 km / sec (roughly what it would take to get it in Earth orbit) would take about 5 x 10^17 Joules, or 1000 MegaWatts continuously for 19 years. That's a lot of energy to get raw materials.
The main belt asteroids are further away, and harder to reach, than Mars. The "Earth crossers" (those whose orbits cross the Earth's orbit) are much closer and, more
important still, typically energetically easy to reach. Some are easier to reach in energy terms than the Moon, and it is energy requirements that tends to dominate the cost.
A number of Earth-crossing asteroids are easier to get to, energetically, than the Moon. (Apollo could certainly have reached some asteroids, which was pointed out at the time, and a lot more Earth-crossing asteroids are known now.) The trip times tend to be long, so you need to be prepared for long duration flights (which is not that different from being prepared for long duration lunar visits, and is also true of any trip to Mars). And, you don't need anything like a lunar module. (With most asteroids, and certainly all of the Earth crossing ones, you will "dock" with them more than "land" on them, the gravity is that week.) The weight saved from the lunar module can be used for provisions instead.
There is plenty of science to do, and if we are ever going to economically exploit the materials in space, we are much more likely to do it with asteroids than with either the Moon or Mars.
Do such problems exist? Well, chaos theory is full of them. You cannot have a system that is truly chaotic and computable at the same time - the two are mutually exclusive. Both are deterministic, but only one is predictable.
But, is that germane here ? I believe that by "computable" you really mean that it is like the "halting problem" - but that doesn't mean that the chaotic system cannot be simulated. I am
not aware of any chaotic system that cannot be simulated (please correct me if I am wrong). In fact, they are simulated all of the time, by our computers, so they could presumably be simulated by whatever is simulating us. That is not the same as predictability, but even if there were things that were unpredictable, that doesn't mean that they couldn't be simulated. (As an example, suppose that you could show that you could not predict whether or not an asteroid was going to hit Mars at some time in the future - that the quantum uncertainly in its position made it impossible, say. But, that doesn't mean that you couldn't simulate it. If I can't predict that it will happen or not, I can't tell if the simulation is right or not either, so how would I know if it is a simulation or reality I am observing ?
It may be that randomness is the best way to determine whether we are in a simulation. Suppose that quantum randomness was actually due to something like a table lookup or an autoregressive function calculation. It is notorious that you cannot calculate randomness on a computer - the sequences you get may look random, but they are not, and if you have enough data and subject it to enough tests you can tell that the sequence is not truly random (say, because it repeats after a long time). So, along the lines of The Nine Billion Names of God,
what we need is a religious order to start recording, say, the times between radioactive decays with a Geiger Counter, and to try and detect the nonrandomness of the resulting number sequence...
Having RTFA, the error ellipse is not nearly circular - there is a very narrow ellipsoid that is only 600 km wide and 400,000 km long and 600 km transverses Mars. The error ellipse of course still crosses Mars, but given this error ellipse, it could still pass many 100,000's of km away.
I have to say, though, that having the 600 km wide part of the error ellipse cross over Mars makes me suspect that this object is going to come pretty close to Mars.
Either Phobos or Deimos could also be hit with this error ellipse, although, again, it's pretty unlikely given the small sizes of these moons.
That is (roughly) the size of the current transverse error ellipse at the closest approach to Mars, so statistically the Asteroid should pass at least that close to Mars.
(Mars's volumetric radius is 3389.5 km, and 3.9 % probability of impact roughly means that the error ellipse is 1 / 0.039 ~ 25 times the projected area of Mars at the time of closet approach. This ignores gravitational focusing, but this is not too important for Mars.)
So, based on the current error ellipse, not only could it hit Mars, it could also hit Deimos, as the error ellipse is now entirely inside Deimos's orbit. The satellite is so small, however, that this is pretty unlikely.
I wonder which will be the first of the three Mars-orbiting spacecraft currently active to observe it ? That would help to improve the OD (orbit determination) in a hurry.
maybe "PC" should go back to meaning "Personal Computer" and cover any device that does computing for personal use regardless of the plumbing it uses...
You are a about 2 decades too late for that. Personally, I think that the confusion was deliberate and brilliant marketing - I can remember getting into "yes, this is my personal computer but it is not a PC" arguments with people about my Mac back about 1985 or so...
My guess is that a lot of small operators won't be able to comply, and that a lot of traffic will move offshore if this is really implemented. This law could take us back to the good old days, when almost Aussie web traffic went across the Pacific.
Slashdot Mirror
Satellites are classified by orbits, and orbital maneuvering, more than by anything else (assuming you don't have direct knowledge of their mission). Different satellites have different orbits for a reason, to support their mission, and their orbits thus provide information about their missions. GPS satellites are in high 12 hour orbits, comm sats are in even higher, 24 hour, orbits, weather satellites are in sun-synchronous polar orbits, etc.
An example : if you have an orbit that passes over Baghdad, big deal, they all will do that sooner or later. If you have one that passes over Baghdad early to mid-morning, when the shadows are nice and long (generally regarded as the best time for surface photography), you may have something. If you have an object whose orbit is continually tweaked to keep passing over Baghdad during mid-morning every few days, and that also happens to be at the perigee of the orbit, then you almost certainly have something. If you look at where it passes over during later-afternoon on other orbits, you may start to gain insight into what other targets are of interest.
You can bet that every serious intelligence service on the planet does this. Amateurs have been doing it since the 1950's, so this is old, old news.
The post didn't say "from Mars and Venus". It said, "from Earth," a planet in which I have some ownership rights.
BTW, I think that Venus will be more terraformable than Mars.
Um, they have found a lot of these (273 candidates this morning), and most of them are not in Solar System type... solar systems. That is indeed having a profound effect on research into planet formation.
From Earth, for example, you could construct...
Yeah, if you don't mind disassembling the whole planet. The NIMBY people would be all over you and, frankly, I would join them on this one.
Apparently not, even at the BBC. What they were saying is that there could be hundreds of worlds in the solar system, not in the galaxy. (They meant in the Kuiper belt, far outside of Pluto and Neptune.)
We have already found 273 extra-solar planets in the galaxy. No one doubts now that there are millions, if not billions, in the galaxy, and a puling "hundreds" of Earth type planets in the galaxy would strike most people following this research as a very low estimate.
From the article : "Some astronomers believe there may be hundreds of small rocky bodies in the outer edges of our own Solar System, and perhaps even a handful of frozen Earth-sized worlds."
I would also regard this as almost not news at all, given the rapid rate of discovery of TNOs (Trans Neptunian Objects), three of which so far are the size of Pluto or larger.
I am old enough to remember reading AI predictions from the early 1960's (see the subject for this post). I think in general predictions from 20+ years ago underestimate developments in computer hardware and greatly overestimate developments in AI, so I see no reason not to predict that the same will hold for 20 year predictions from our time.
I happen to think that we do have a super-intelligence that greatly exceeds any human intelligence - it's called science, and it is and has for decades been a
human-machine symbiosis. That will continue to become more effective as time passes, regardless of the state of machine consciousness.
This means a new T1 for every store, as a T-Mobile provided T1 was part of the original deal.
That means a lot of work for AT&T installers, and will take a while.
Is this part of the strike settlement ? I hope the writers vote it down - I don't want any TV writers nagging me !
Gee, then you miss your plane. I have missed many planes. It happens, even to the "get there 3 hours early" crowd. Unless it's Saigon, 1973, there will be another.
I posted a query to a Linux newsgroup, and a respondent told me that the solution was to open a command prompt and type "man find", which I am aware is a polite way of saying "screw you, newbie", but which I dutifully followed anyway and got an output screen of which the first paragraph was:
Just thought I might help him out. Sounds like he needs it.
AmericaFree.TV has a regular Iranian audience, and it is still there today. Egypt is still badly affected, but not Iran, at least, not so far.
A lot more information is available from the Renesys Blog.
It was both the Flag Telecom and SEA-ME-WEA 4 cables outside of Alexandria, Egypt. The SEA-ME-WEA 3 cable is apparently OK.
In long distance telecommunications, you really need another path going "the other way around" to be safe. For example, many of the large companies with back-offices in India pay for routes both over the Atlantic to the Middle East to India (which might have been broken by this) and also West Coast to Pacific to Singapore to India (which would not have been).
At AmericaFree.TV, the steady Egyptian audience went to zero yesterday, presumably because of the break, while the audience in Iran, Iraq, the GCC, Pakistan and India did not seem to be affected.
Power only works when you respect the people you control.
It is fair to say that my experience of the world does not provide much support for this notion.
The idea of flying 2,000-pound cameras with kites...
Talk about not RTFA. The Lawrence Camera Weighed 46 Pounds.
There have been no direct detections of gravitational waves so far. There have been indirect detections (most robustly with the various binary millisecond pulsars, whose orbits slowly decay due to their radiating energy away in gravitational waves), but no direct detections. However, this was not really seen as an issue, as gravitational wave searches before LIGO suffered from the problem that there were no known sources strong enough for them to detect with good probability. You have to start somewhere, and there is always the chance of either good luck, say a close supernova, or some unknown source that is stronger than expected, but I believe that this is the first actual event whose gravitational waves, by a reasonable model, had a chance of being detected with existing equipment. One such non-detection means nothing - maybe the Gamma Ray Burst occurred way behind the Andromeda Galaxy, for example. If this is consistently repeated, we will eventually conclude that there is something wrong with our physics or our astrophysics, but it is much too soon for that.
I have no idea what their vision is. Based on my experience, there literally may not be one. (NASA suffered greatly when all of the original space enthusiasts retired in the 1970's, as they were largely replaced by bureaucrats.) However, my vision (the only one I can really speak for) is to create sustainable human habitations in space.
Moving asteroids is not trivial. Asteroid densities are around a few grams / cm^3, so a 100 meter "diameter" asteroids (ones that small are highly unlikely to be spherical) will have a mass of maybe 10 Megatons (or 10^10 kg). Changing the velocity of that mass by 10 km / sec (roughly what it would take to get it in Earth orbit) would take about 5 x 10^17 Joules, or 1000 MegaWatts continuously for 19 years. That's a lot of energy to get raw materials.
The main belt asteroids are further away, and harder to reach, than Mars. The "Earth crossers" (those whose orbits cross the Earth's orbit) are much closer and, more important still, typically energetically easy to reach. Some are easier to reach in energy terms than the Moon, and it is energy requirements that tends to dominate the cost.
I have felt this for a long time.
A number of Earth-crossing asteroids are easier to get to, energetically, than the Moon. (Apollo could certainly have
reached some asteroids, which was pointed out at the time, and a lot more Earth-crossing asteroids are known now.) The trip times tend to be long,
so you need to be prepared for long duration flights (which is not that different from being prepared for long duration lunar visits, and is also
true of any trip to Mars). And, you don't need anything like a lunar module. (With most asteroids, and certainly all of the Earth crossing ones, you will "dock" with
them more than "land" on them, the gravity is that week.) The weight saved from the lunar module can be used for provisions instead.
There is plenty of science to do, and if we are ever going to economically exploit the materials in space, we are much more likely to
do it with asteroids than with either the Moon or Mars.
Do such problems exist? Well, chaos theory is full of them. You cannot have a system that is truly chaotic and computable at the same time - the two are mutually exclusive. Both are deterministic, but only one is predictable.
But, is that germane here ? I believe that by "computable" you really mean that it is like the "halting problem" - but that doesn't mean that the chaotic system cannot be simulated. I am not aware of any chaotic system that cannot be simulated (please correct me if I am wrong). In fact, they are simulated all of the time, by our computers, so they could presumably be simulated by whatever is simulating us. That is not the same as predictability, but even if there were things that were unpredictable, that doesn't mean that they couldn't be simulated. (As an example, suppose that you could show that you could not predict whether or not an asteroid was going to hit Mars at some time in the future - that the quantum uncertainly in its position made it impossible, say. But, that doesn't mean that you couldn't simulate it. If I can't predict that it will happen or not, I can't tell if the simulation is right or not either, so how would I know if it is a simulation or reality I am observing ?
It may be that randomness is the best way to determine whether we are in a simulation. Suppose that quantum randomness was actually due to something like a table lookup or an autoregressive function calculation. It is notorious that you cannot calculate randomness on a computer - the sequences you get may look random, but they are not, and if you have enough data and subject it to enough tests you can tell that the sequence is not truly random (say, because it repeats after a long time). So, along the lines of The Nine Billion Names of God, what we need is a religious order to start recording, say, the times between radioactive decays with a Geiger Counter, and to try and detect the nonrandomness of the resulting number sequence...
The basis of the suit is that Apple doesn't support WMA ? Why do I suspect that Microsoft is behind this somewhere ?
Having RTFA, the error ellipse is not nearly circular - there is a very narrow ellipsoid that is only 600 km wide and 400,000 km long and
600 km transverses Mars. The error ellipse of course still crosses Mars, but given this error ellipse, it could still pass many 100,000's of km away.
I have to say, though, that having the 600 km wide part of the error ellipse cross over Mars makes me suspect that this object is going to come pretty close to Mars.
Either Phobos or Deimos could also be hit with this error ellipse, although, again, it's pretty unlikely given the small sizes of these moons.
That is (roughly) the size of the current transverse error ellipse at the closest approach to Mars, so statistically the Asteroid should pass at least that close to Mars.
(Mars's volumetric radius is 3389.5 km, and 3.9 % probability of impact roughly means that the error ellipse is 1 / 0.039 ~ 25 times the projected area of Mars at the time of closet approach. This ignores gravitational focusing, but this is not too important for Mars.)
So, based on the current error ellipse, not only could it hit Mars, it could also hit Deimos, as the error ellipse is now entirely inside Deimos's orbit.
The satellite is so small, however, that this is pretty unlikely.
I wonder which will be the first of the three Mars-orbiting spacecraft currently active to observe it ? That would help to improve the OD (orbit determination) in a hurry.
maybe "PC" should go back to meaning "Personal Computer" and cover any device that does computing for personal use regardless of the plumbing it uses...
You are a about 2 decades too late for that. Personally, I think that the confusion was deliberate and brilliant marketing - I can remember getting into "yes, this is my personal computer but it is not a PC" arguments with people about my Mac back about 1985 or so...
Oh, I can see that this will work out well.
My guess is that a lot of small operators won't be able to comply, and that a lot of traffic will move offshore if this is really implemented. This law could take us back to the good old days, when almost Aussie web traffic went across the Pacific.