As far as mission-critical micro-electronics (like CPUs or CCDs), bigger is better for radiation-resistance. That's why many spacecraft still use 286 - 486 chips because greater speed isn't needed, are cheaper to radiation-harden and are less complicated (harder to break) than new chips. In the case of CCDs, it is mentioned in the article that lenses need to be created with greater precision for high-resolution CCDs than lower resolution ones. I'm sure this wouldn't be a problem for NASA, so I would guess they went with the lower resolution CCD due to the larger size of each sensor and because it met the mission requirements. They don't mention this in the article, but the rover is very bandwidth-limited, so it wouldn't be possible to send back any more information than it already is anyways.
They mentioned that the design process of the Huble's CCDs at a resolution of 800 x 800 contributed to the current mass production of consumer CCD cameras, so I don't think they are afraid of pushing the envelope if it is needed to meet mission requirements.
I know Lisp zealots claim to be able to generally develop apps the fastest. Performance is great as is compile time, but the syntax is so different from other languages that it takes a while to pick up.
I recently heard that universities in the UK were having a very difficult time retaining top professors due to limited financing. Apparently, many of them are moving to more afluent colleges overseas, especially to the US. Apparently, the funding per student for higher education in the UK has dropped significantly over the past 30-40 years or so.
As far as I can tell, you are both correct and not. Peaceful civil rights activists certainly wouldn't be considered terrorists by that definition. If you are referring to the "intimidation or coercion" clause, I think you are misunderstanding the definitions of those words:
intimidation: to make timid or fearful: FRIGHTEN, especially: to compel or deter by or as if by threats (from Merriam-Webster)
Obviously, simply protesting is not fearful, although violent protests could be considered such. I agree that this is a rather weak condition for calling a person a terrorist, though and could be easily abused by law enforcement.
While "terrorism" is very broadly defined in the colloquial sense, isn't it fairly narrowly defined in the legal sense? Any lawyers/law students know the answer? It seems that a decent definition would be something along the lines "A person engaging in an act to terrorize masses of other people through destructive/lethal means."
I was merely pointing out that he wasn't completely off base (at least as far as numbers are concerned). He didn't say where in the tunnel he would park and I recall that some sections (such a where there's an underground interchange) cost significantly more per mile to build than others.
This doesn't really help his argument, though, because he is ignoring the fact that an elevated highway will be demolished, creating great economic potential for the city. It also ignores the fact that the tunnel isn't a parking lot. There's a huge difference between having hundreds of thousands of cars going through the tunnel (quickly) per day and a space where thousands of cars would be semi-perminantly sitting there.
FYI, "an order of magnitude" refers to 10^1, two orders of magniguted would be 10^2 (100), etc. You asserted that the cost of the tunnel for the car's area would be $804,317.40 and that he would make at least $30k per year for 26 years ($780,000), which not only supports his original claim, but is also cleary within $8mil within his claim (an order of magnitude). My intent was that even if you were less generous with your numbers, your result would still be within an order of magnitude of his claim, which in my opinion would certainly not prove his claim as being absurd.
Still, by your numbers, he's within an order of magnitude of being right. And if you consider that some sections of the construction cost much more than other sections, he may be completely correct for those areas. Fortunately, the tunnel isn't a parking lot (yet), otherwise he'd have a point.
You wanted to know whether "the X-Prize is really meaningful in the scale of realistic space flight" no? If this is the point, then the parent poster was mostly on the money. Satellites are designed to be permenantly in orbit, never to (operationally) return to earth. People, on the other hand, do need to come back to earth. This is a huge difference (trying no to be too facetious:). The goal of the X-Prize is meant to be a stepping stone to getting people from point A to point B very quickly, cheaply and reliably. This certainly does not require one to enter orbit. However, by getting above nearly all of the earth's atmoshpere, there is next to no drag, making it possible to travel supersonically without the tremendous drag that is usually associated with it.
A better example on your part would have been the Minuteman intercontinental missle, as it is designed more closely to the goal of the X-Prize (not blowing people to bits, but getting from one end of the earth to the other in a hurry). The difference is that the vehicle needs to be reusable and have life support for 3 people. So, in response to your original question, yes this would be a significant achievement (and to your implied statement, no this has never been done before, even by national governments much less private companies). The hope is that by achieving the goal of this competition, there will consequentally be an immediate commercial application that will be profitable enough to sustain growth for this type of transportation, leading to more improvements. In time, this would hopefully lower the costs to getting to suborbital speeds, leading to lower costs of getting people to orbit.
You might be surprised. I can recall being an assistant at a teaching seminar back in junior high school teaching the teachers (ironic, no?) how to use the Macs that we had (this was back around '93). Even the simplest tasks needed explanations.
The only reason that Macs seem to be so intuitive is because you are already familiar with the general GUI paradigm. Once you know the basics (what an application is, what files are, how to find files/directories, etc.), you can pick up things very quickly. On Unix, once you are familiar with the basic command line syntax, several programs (such as grep, ls, man, etc.) you can make quick progress.
I agree with you that getting going on a Mac is certainly more straight-forward, but it is not an instantaneous process if you are starting from a clean slate.
As it currently is, volunteer hams provide emergency communication and coordination during emergencies (such as on 9/11 when they helped coordinate hospitals because the cell network was jammed).
If, on a normal basis, hams can't use their equipment due to interference from powerline broadband, they'll give up their hobby and you'll loose that extra layer of defense on the next emergency.
There's also the issue of interference with other users of this frequency spectrum, such as flight controllers for GA (as mentioned in the article). Like other frequency ranges, HF is very valuable and there had better be a damn good reason to screw it up and frankly VPN in rural areas doesn't cut it.
There are at least two other technologies that could let you have VPN when DSL and cable isn't available: WiFi and fixed, radio towers that I believe are in the microwave range (at least here in Boulder, although they cost nearly as much as satellite).
Considering it takes about 90 minutes to orbit the earth at LEO (or 45 min to go 'anywhere'), getting anywhere in 2hrs is very impressive. I wonder if it flies inverted so that its lift prevents it from entering orbit.
CU (U of Colorado), Boulder had 10BaseT everywhere when I graduated (3 years ago). I bet they have wireless access points by now, although I would stick with 10BaseT if I had the choice.
While that is how it is designed, that doesn't mean that someone with nasty intentions couldn't fill them with 100% methanol (or something worse). Unless the TSA uses sensing equipment sensitive enough to tell what concentration of what chemical is in the fuel cells, it would provide good camouflage for the nasties. Of course, we are still talking about really small amounts of stuff, so I bet it would still be difficult for a terrorist to use it to bring down a jet.
It's going to be cloudy all day today here in Boulder. Once it clears up, I'll keep an eye out for it and try to get some video. Check my journal in a week to see whether or not I was able to get something.
According to a very recent news report/special (I saw it on broadcast TV live a few days ago), the jet fuel had been completely consumed within a few minutes. Kerosene doesn't simmer, it explodes and there were huge holes in the buildings providing plenty of air for the fuels to combust.
The heat from the paper fire was very extreme. I don't know how you would think there is some sort of upper limit for paper combustion. If there is fire adding heat to the floor above it, and the fire there is adding heat to the floor above it and so on, how is the heat going to escape fast enough to come to a stable, normal temperature? Answer: it doesn't! Just like a forest fire, the fire becomes an inferno and can reach very high temperatures, hundreds of degrees at least (I think the show estimated that temps may have reached 1000F). It didn't need to be hot enough to melt the steel, but merely soften it a bit, which happens at much lower temperatures (say 700F).
This is OT, but I recently found out that the reason the fires in the Trade Towers were so enormous were because of all of the paper in the buildings. In fact, all of the jet fuel burned off within a few minutes. If the buildings hadn't been stuffed with combustible materials (esp. paper), the fires almost certainly could have been brought quickly under control, saving many, many lives (although the buildings still probably would have been torn down later at great expense).
I remember reading that it now takes NASA substantially more man-hours to do the same tasks now than before computers were used for design/CAD work. If I remember correctly, it took engineers roughly half the amount of time to design a rocket like the Saturn V than it would today using CAD (Computer Aided Design)! Also, much more paper is used now then back then when all of the drafting was hand-drawn, with typewriters used for everything else. I think they also tended to make fewer mistakes because they were more closely involved in the numbers, not using a potentially buggy black box to help them out.
That's not a problem at all. Another word for low earth orbit (LEO) is a parking orbit, a place where satellites can orbit a bit before heading to higher altitudes. You burn X1 amount of fuel to get to the LEO altitude, then burn X2 amount of fuel to cirularize your orbit. Then after doing whatever you feel like (such as docking with an orbiting lunar lander to be reused for this mission) and finally burn X3 amount of fuel to break out of earth's gravity well and get to the moon. An important point here is that you are accelerating on each burn, never slowing down (and thereby wasting energy), so either way you burn the same amount of fuel. The only downside is adding complexity to the mission--another chance for something to go wrong.
To have a reusable lander, though, would require one substantially different than the Apollo mission (half of which was left on the lunar surface). It would need to be substantially heavier for the additional equipment it would need and probably need to be refueled in a way similar to how the ISS is refueled. Or perhaps use a lander similar to the original, simply rebuilding the bottom portion of it (containing the enormous amount of fuel needed for landing on the lunar surface), docking to the reusable upper portion, which would still require refilling for the launch from the lunar surface to lunar orbit.
Why shouldn't you consider it a "true picture"? Many astronomical and other scientific (sonar, radar, etc.) images are formed in this way (such as the popular Horsehead Nebula image taken by the Hubble telescope). Also, many very high detailed photos use some sort of mechanical process to take seperate images and later do some processing to combine them. If done correctly, there is no difference in quality between this method and an instantaneous one (at least for quasi-static scenes). Using a mechanical measure to determine what is or isn't a "true picture" seems rather arbitrary and silly to me.
The GPS satellites are using their uplink frequency all the time, receiving new precise orbit information from tracking stations on the ground. This orbit data is then continuously transmitted by the satellites so that receivers on the ground know where they are. I would guess that the uplink signal is heavily encrypted so that any jam on that frequency would simply cause the satellite to not be able to update its orbit info while in the area.
The US would probably never need to jam the signals themselves as the Galileo system is probably similar to the GPS system where the civilian frequency can be dithered or even turned off in a specified region. So if the Galileo sytstem where in place today, the US would probably only need to make a phone call asking that the satellites turn off their civilian signal over Iraq and Afghanistan for the next few months and the EU would probably comply.
Try the ACE classes. It will work on any platform, even embeded ones (at least with the serial port). (the classes you would be interested in are ACE_DEV_IO and ACE_DEV_Connector).
He's talking about the problem off of the US coast I presume. The article doesn't say when that problem started, but did say that it would be fixed within a week.
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They mentioned that the design process of the Huble's CCDs at a resolution of 800 x 800 contributed to the current mass production of consumer CCD cameras, so I don't think they are afraid of pushing the envelope if it is needed to meet mission requirements.
I know Lisp zealots claim to be able to generally develop apps the fastest. Performance is great as is compile time, but the syntax is so different from other languages that it takes a while to pick up.
I recently heard that universities in the UK were having a very difficult time retaining top professors due to limited financing. Apparently, many of them are moving to more afluent colleges overseas, especially to the US. Apparently, the funding per student for higher education in the UK has dropped significantly over the past 30-40 years or so.
intimidation: to make timid or fearful: FRIGHTEN, especially: to compel or deter by or as if by threats (from Merriam-Webster)
Obviously, simply protesting is not fearful, although violent protests could be considered such. I agree that this is a rather weak condition for calling a person a terrorist, though and could be easily abused by law enforcement.
While "terrorism" is very broadly defined in the colloquial sense, isn't it fairly narrowly defined in the legal sense? Any lawyers/law students know the answer? It seems that a decent definition would be something along the lines "A person engaging in an act to terrorize masses of other people through destructive/lethal means."
This doesn't really help his argument, though, because he is ignoring the fact that an elevated highway will be demolished, creating great economic potential for the city. It also ignores the fact that the tunnel isn't a parking lot. There's a huge difference between having hundreds of thousands of cars going through the tunnel (quickly) per day and a space where thousands of cars would be semi-perminantly sitting there.
FYI, "an order of magnitude" refers to 10^1, two orders of magniguted would be 10^2 (100), etc. You asserted that the cost of the tunnel for the car's area would be $804,317.40 and that he would make at least $30k per year for 26 years ($780,000), which not only supports his original claim, but is also cleary within $8mil within his claim (an order of magnitude). My intent was that even if you were less generous with your numbers, your result would still be within an order of magnitude of his claim, which in my opinion would certainly not prove his claim as being absurd.
Still, by your numbers, he's within an order of magnitude of being right. And if you consider that some sections of the construction cost much more than other sections, he may be completely correct for those areas. Fortunately, the tunnel isn't a parking lot (yet), otherwise he'd have a point.
A better example on your part would have been the Minuteman intercontinental missle, as it is designed more closely to the goal of the X-Prize (not blowing people to bits, but getting from one end of the earth to the other in a hurry). The difference is that the vehicle needs to be reusable and have life support for 3 people. So, in response to your original question, yes this would be a significant achievement (and to your implied statement, no this has never been done before, even by national governments much less private companies). The hope is that by achieving the goal of this competition, there will consequentally be an immediate commercial application that will be profitable enough to sustain growth for this type of transportation, leading to more improvements. In time, this would hopefully lower the costs to getting to suborbital speeds, leading to lower costs of getting people to orbit.
The only reason that Macs seem to be so intuitive is because you are already familiar with the general GUI paradigm. Once you know the basics (what an application is, what files are, how to find files/directories, etc.), you can pick up things very quickly. On Unix, once you are familiar with the basic command line syntax, several programs (such as grep, ls, man, etc.) you can make quick progress.
I agree with you that getting going on a Mac is certainly more straight-forward, but it is not an instantaneous process if you are starting from a clean slate.
When dating chimpanzees is outlawed, only outlaws will date chimpanzees. What's your point?
If, on a normal basis, hams can't use their equipment due to interference from powerline broadband, they'll give up their hobby and you'll loose that extra layer of defense on the next emergency.
There's also the issue of interference with other users of this frequency spectrum, such as flight controllers for GA (as mentioned in the article). Like other frequency ranges, HF is very valuable and there had better be a damn good reason to screw it up and frankly VPN in rural areas doesn't cut it.
There are at least two other technologies that could let you have VPN when DSL and cable isn't available: WiFi and fixed, radio towers that I believe are in the microwave range (at least here in Boulder, although they cost nearly as much as satellite).
So you're saying that VPN is more important than the hobby of ham radios, their use during emergency situations, and general aviation?
Considering it takes about 90 minutes to orbit the earth at LEO (or 45 min to go 'anywhere'), getting anywhere in 2hrs is very impressive. I wonder if it flies inverted so that its lift prevents it from entering orbit.
CU (U of Colorado), Boulder had 10BaseT everywhere when I graduated (3 years ago). I bet they have wireless access points by now, although I would stick with 10BaseT if I had the choice.
While that is how it is designed, that doesn't mean that someone with nasty intentions couldn't fill them with 100% methanol (or something worse). Unless the TSA uses sensing equipment sensitive enough to tell what concentration of what chemical is in the fuel cells, it would provide good camouflage for the nasties. Of course, we are still talking about really small amounts of stuff, so I bet it would still be difficult for a terrorist to use it to bring down a jet.
It's going to be cloudy all day today here in Boulder. Once it clears up, I'll keep an eye out for it and try to get some video. Check my journal in a week to see whether or not I was able to get something.
The heat from the paper fire was very extreme. I don't know how you would think there is some sort of upper limit for paper combustion. If there is fire adding heat to the floor above it, and the fire there is adding heat to the floor above it and so on, how is the heat going to escape fast enough to come to a stable, normal temperature? Answer: it doesn't! Just like a forest fire, the fire becomes an inferno and can reach very high temperatures, hundreds of degrees at least (I think the show estimated that temps may have reached 1000F). It didn't need to be hot enough to melt the steel, but merely soften it a bit, which happens at much lower temperatures (say 700F).
This is OT, but I recently found out that the reason the fires in the Trade Towers were so enormous were because of all of the paper in the buildings. In fact, all of the jet fuel burned off within a few minutes. If the buildings hadn't been stuffed with combustible materials (esp. paper), the fires almost certainly could have been brought quickly under control, saving many, many lives (although the buildings still probably would have been torn down later at great expense).
I remember reading that it now takes NASA substantially more man-hours to do the same tasks now than before computers were used for design/CAD work. If I remember correctly, it took engineers roughly half the amount of time to design a rocket like the Saturn V than it would today using CAD (Computer Aided Design)! Also, much more paper is used now then back then when all of the drafting was hand-drawn, with typewriters used for everything else. I think they also tended to make fewer mistakes because they were more closely involved in the numbers, not using a potentially buggy black box to help them out.
To have a reusable lander, though, would require one substantially different than the Apollo mission (half of which was left on the lunar surface). It would need to be substantially heavier for the additional equipment it would need and probably need to be refueled in a way similar to how the ISS is refueled. Or perhaps use a lander similar to the original, simply rebuilding the bottom portion of it (containing the enormous amount of fuel needed for landing on the lunar surface), docking to the reusable upper portion, which would still require refilling for the launch from the lunar surface to lunar orbit.
Depends on the quality setting, obviously. At reasonable quality (ie, without loosing much detail) it would probably still be hundreds of megs.
Why shouldn't you consider it a "true picture"? Many astronomical and other scientific (sonar, radar, etc.) images are formed in this way (such as the popular Horsehead Nebula image taken by the Hubble telescope). Also, many very high detailed photos use some sort of mechanical process to take seperate images and later do some processing to combine them. If done correctly, there is no difference in quality between this method and an instantaneous one (at least for quasi-static scenes). Using a mechanical measure to determine what is or isn't a "true picture" seems rather arbitrary and silly to me.
The US would probably never need to jam the signals themselves as the Galileo system is probably similar to the GPS system where the civilian frequency can be dithered or even turned off in a specified region. So if the Galileo sytstem where in place today, the US would probably only need to make a phone call asking that the satellites turn off their civilian signal over Iraq and Afghanistan for the next few months and the EU would probably comply.
Try the ACE classes. It will work on any platform, even embeded ones (at least with the serial port). (the classes you would be interested in are ACE_DEV_IO and ACE_DEV_Connector).
He's talking about the problem off of the US coast I presume. The article doesn't say when that problem started, but did say that it would be fixed within a week.