You're both correct. It is free-fall and microgravity. If you are in free-fall (say at about 0.97g acceleration), you don't feel the 0.97g. The space station is still well within earth's gravity well but experience microgravity.
The payloads would have to have similar orbits (or at least be placed in roughly the same plane). The extra fuel needed to put the various payloads in their own correct orbit quickly diminishes any cost savings by putting them on the same lower stage rocket.
We aren't talking about any beginner, we are talking about somebody's mom. Anything more than simple HTML may be a bit too much for her at first. I have a friend who was nearly totally computer illiterate until she discovered HTML. Now she likes writing web pages and dabbles in javascript. The intant gratification and initial simplicity can't be overrated.
Re:There's a quicker and more effective way (w/o G
on
Open Maps?
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OK. Now that I've figured out how to do IRC I'll be there. I guess that explains why nobody has ever commented in my journal. I need to check my settings.
Re:There's a quicker and more effective way (w/o G
on
Open Maps?
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· Score: 1
OK. I figured out how to add new servers in mIRC. Duh. Anyway, you seem to be quite knowledgable about what is available and perhaps what would be most needed in the GIS world right now and I would welcome any input that you may have.
My current knowledge is mostly centered on GPS technology itself, not cartology so much of this is new to me. I'm currently working on a couple of projects in my spare time, including a small Windows CE program to map GIS data on a PocketPC, a small C++ program to do turn-by-turn directions given a network of nodes and segment info (to be integrated with the WinCE program in the future) and a GUI to prepare the data for the WinCE program. It seems like the GUI could be modified to download and upload GIS data to a server so people could coordinate their efforts.
Re:There's a quicker and more effective way (w/o G
on
Open Maps?
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· Score: 1
Sure. I haven't played much with IRC. Do I simply connect to a random server and then type join #openmap or do I have to connect to a particular server? For now, I'll add a journal entry so we can discuss there.
Re:There's a quicker and more effective way (w/o G
on
Open Maps?
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· Score: 1
I wish I could. It's still mostly on paper. I'm also still looking at all of the free GIS software available to make sure I'm not duplicating something that already exists.
I think the program I proposed would be especially useful in European and other countries (non-US) where free GIS data is hard to come by.
Depends on your local government I guess. Here in Boulder, Colorado there's a bike map published by the city government: http://www.ci.boulder.co.us/goboulder/pdf/bike01.p df. It shows which roads have bike lanes, wide shoulders where sidewalk paths are, etc.
Re:Try the County Assessor yet?
on
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I presume he meant that they would be using two GPS receivers, on fixed and one heading down the street. It would be kind of silly to bother using an expensive GPS receiver kinematically without corrections; sort of defeats the purpose.
I agree with you, though. Why would he need centimeter level accuracy for his purposes? Consumer GPS receivers with WAAS corrections can get meter level accuracy easily (I've verified this comparing one against a reference station where I work).
There's a quicker and more effective way (w/o GPS)
on
Open Maps?
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A more practicle approach would be to write an open-source program which would allow people to trace routes over aerial photographs. There would be a toolbar saying whether you're creating an in-city street, highway, interstate, etc. and so on. Once the app was finished (probably would take 10 thousand lines of code easy for a minimal version), people would be shipped data units (the photographs and existing vector data if available) and complete it to the best of their ability. Sort of like the Gutenberg project.
I'm actually working on such a program right now, but it's so pre-alpha that I haven't even put it on sourceforge yet. A problem of relying strictly on aerial photographs is that they are usually years old, so any recent road construction wouldn't be present.
I don't know about all of that. While some things may become cheaper, many things will simply become better (not cheaper).
For instance, those power tools in that old Sears catalog probably didn't cost more than modern power tools, possibly less since they were simpler and didn't each have their own motor and battery (even after adjusting for inflation). Laptops only cost about $1000 less than they did 15 years ago and have been pretty steady for the last 6 years or so.
I predict that many technologies will start off relatively expensive and then stabilize after 5-10 years, just as many technologies before them did (TVs, microwaves, etc.).
However the theory of evolution has had no credible evidence against it, neither has gravity, or thermodynamics.
*cough* quantum mechanics *cough*
Just hypothetically, what could possibly disprove evolution without involving time travel? To me it seems that it isn't possible to disprove evolution with any amount of observations of the earth given present technology and our knowledge of physics, etc. That, however, doesn't prove that it is correct.
Other theories, like General Relativity, can be disproven with a clever test. We know that there is a discontinuity between the predictions of relativity and the predictions of quantum mechanics, so clearly one (or both) are not correct. I can't imagine how a similar statement could be made about evolution. I'm not saying evolution is wrong, it simply isn't disprovable.
Only small addendums.
It's easy to say that Newton was slightly off, but come on. General relativity forms a completely different picture of the universe than Newton envisioned, with quantum mechanics even more bizarre.
You're probably going to be modded to oblivion, but you are essentially correct. Remember what happened to Rwanda 10 years ago? No one had an interest in the area and could have hardly cared less that a huge genocide was occuring. The UN was there before, during and after the genocide, talking the whole time to the people commiting the genocide, but doing nothing (with force) to stop it.
Wasn't there a story on slashdot a month or two ago about a project going on at some university doing exactly that? With a 3d model of the university, you would be able to determine your position and orientation simply by taking a picture of neighboring buildings.
Biodiesel still releases CO2 into the atmosphere and we really need to avoid that.
As someone in a sibling thread stated, the CO2 the algea uses to produce oil comes from the atmosphere itself, so any CO2 released in combustion can't exceed the CO2 removed from the atmosphere in the first place (the process is CO2 neutral). Pretty cool I'd say.
Power might be a problem. Gamma rays take a rediculous amount of power to generate. The antenna might be a problem too. Aren't they next to impossible to stop?
Err, DGPS isn't that useful in a combat setting. The nice thing about GPS is that it is completely passive. However, DGPS is an active system where the data from the reference receiver needs to be sent to the munition. This signal could be blocked or, worse yet, tracked by the oposing force and destroyed. It also doesn't work in burst mode, you must continuously transmit corrections for it to achieve good accuracy.
Also, DGPS only works when the L1 frequency is on. This frequency could conceivably be turned off by NAVSTAR over a region (it hasn't happened to date, but the US has never fought an enemy that had GPS-guided bombs). Another point: if the DOP is set high enough on SA, it could really restrict the range that DGPS could work over.
You must keep in mind first of all that GPS was designed by the US military for the US military, with any benefits for marine and civilian navigation a bonus.
Of course, 2-frequency phase tracking receivers cost a fortune (well, not by military standards...). In addition, it takes a certain amount of time to resolve ambiguities, which is even harder when you're moving (ie, a missile) and even harder when you're moving fast. And should a cycle slip occure, you have to start all over again, not something very practicle for a missile. (for the laymen: phase tracking is only useful when the number of frequency cycles between the receiver and the satellite are known. When this isn't known, there isn't nearly as much of an advantage)
Also, AFAIK GPS can be selectively turned on and off over a given region, either by turning off L1 (the civilian frequency) or both L1 and L2 (unlikely to ever happen). If they were to turn L1 off, any civilian receiver in the area would be useless, even top-of-the line civilian Trimbles. On the plus side, they can also turn the y-code encryption off on L2, like they did in Gulf War 1 (they didn't have enough military receivers at the time).
Of course, GPS isn't the only way to have precision munitions. In Gulf War 1, most of the munitions dropped by the US were laser-guided.
All satellites in orbit about Earth are going in circles about the earth (technically, ellipses are the closest Euclidian approximation of their path).
Others already mentioned that the standard GPS constellation is at a mid-level orbit (about 20,000km altitude). In addition, there are two GPS satellites in geosynchronous orbit, providing WAAS coverage. While they are fixed in the sky, they are still going in circles about the Earth with a period of 24 hours.
Well, the US government has massive reserves of oil for emergency purposes. A more likely scenario would be another Arab oil embargo like in the 70s. While it would greatly inconvenience many people, there wouldn't be mass starvation or anything like that. There's still untapped reserves in Alaska that could be used in an emergency, so it's pretty inconceivable that the US could suddenly be without even enough oil to ship food from farms to cities.
Slashdot Mirror
You're both correct. It is free-fall and microgravity. If you are in free-fall (say at about 0.97g acceleration), you don't feel the 0.97g. The space station is still well within earth's gravity well but experience microgravity.
The payloads would have to have similar orbits (or at least be placed in roughly the same plane). The extra fuel needed to put the various payloads in their own correct orbit quickly diminishes any cost savings by putting them on the same lower stage rocket.
We aren't talking about any beginner, we are talking about somebody's mom. Anything more than simple HTML may be a bit too much for her at first. I have a friend who was nearly totally computer illiterate until she discovered HTML. Now she likes writing web pages and dabbles in javascript. The intant gratification and initial simplicity can't be overrated.
OK. Now that I've figured out how to do IRC I'll be there. I guess that explains why nobody has ever commented in my journal. I need to check my settings.
My current knowledge is mostly centered on GPS technology itself, not cartology so much of this is new to me. I'm currently working on a couple of projects in my spare time, including a small Windows CE program to map GIS data on a PocketPC, a small C++ program to do turn-by-turn directions given a network of nodes and segment info (to be integrated with the WinCE program in the future) and a GUI to prepare the data for the WinCE program. It seems like the GUI could be modified to download and upload GIS data to a server so people could coordinate their efforts.
Sure. I haven't played much with IRC. Do I simply connect to a random server and then type join #openmap or do I have to connect to a particular server? For now, I'll add a journal entry so we can discuss there.
I think the program I proposed would be especially useful in European and other countries (non-US) where free GIS data is hard to come by.
Spoken like a true A/C. Kudos to you and your A/C brethren for invigorating this discussion.
Depends on your local government I guess. Here in Boulder, Colorado there's a bike map published by the city government: http://www.ci.boulder.co.us/goboulder/pdf/bike01.p df. It shows which roads have bike lanes, wide shoulders where sidewalk paths are, etc.
I agree with you, though. Why would he need centimeter level accuracy for his purposes? Consumer GPS receivers with WAAS corrections can get meter level accuracy easily (I've verified this comparing one against a reference station where I work).
I'm actually working on such a program right now, but it's so pre-alpha that I haven't even put it on sourceforge yet. A problem of relying strictly on aerial photographs is that they are usually years old, so any recent road construction wouldn't be present.
For instance, those power tools in that old Sears catalog probably didn't cost more than modern power tools, possibly less since they were simpler and didn't each have their own motor and battery (even after adjusting for inflation). Laptops only cost about $1000 less than they did 15 years ago and have been pretty steady for the last 6 years or so.
I predict that many technologies will start off relatively expensive and then stabilize after 5-10 years, just as many technologies before them did (TVs, microwaves, etc.).
*cough* quantum mechanics *cough*
Just hypothetically, what could possibly disprove evolution without involving time travel? To me it seems that it isn't possible to disprove evolution with any amount of observations of the earth given present technology and our knowledge of physics, etc. That, however, doesn't prove that it is correct.
Other theories, like General Relativity, can be disproven with a clever test. We know that there is a discontinuity between the predictions of relativity and the predictions of quantum mechanics, so clearly one (or both) are not correct. I can't imagine how a similar statement could be made about evolution. I'm not saying evolution is wrong, it simply isn't disprovable.
Only small addendums.
It's easy to say that Newton was slightly off, but come on. General relativity forms a completely different picture of the universe than Newton envisioned, with quantum mechanics even more bizarre.
I better not turn my radio on then. Didn't want to listen to her anyway.
You're probably going to be modded to oblivion, but you are essentially correct. Remember what happened to Rwanda 10 years ago? No one had an interest in the area and could have hardly cared less that a huge genocide was occuring. The UN was there before, during and after the genocide, talking the whole time to the people commiting the genocide, but doing nothing (with force) to stop it.
Wasn't there a story on slashdot a month or two ago about a project going on at some university doing exactly that? With a 3d model of the university, you would be able to determine your position and orientation simply by taking a picture of neighboring buildings.
As someone in a sibling thread stated, the CO2 the algea uses to produce oil comes from the atmosphere itself, so any CO2 released in combustion can't exceed the CO2 removed from the atmosphere in the first place (the process is CO2 neutral). Pretty cool I'd say.
Don't they usually use noisy, dirty two-stroke engines? Unless a top speed of 30mph is good enough for you using an electric moped.
Power might be a problem. Gamma rays take a rediculous amount of power to generate. The antenna might be a problem too. Aren't they next to impossible to stop?
They're working on it. It will probably take at least a decade or two before they have nearly as many as the US though.
Also, DGPS only works when the L1 frequency is on. This frequency could conceivably be turned off by NAVSTAR over a region (it hasn't happened to date, but the US has never fought an enemy that had GPS-guided bombs). Another point: if the DOP is set high enough on SA, it could really restrict the range that DGPS could work over.
Of course, 2-frequency phase tracking receivers cost a fortune (well, not by military standards...). In addition, it takes a certain amount of time to resolve ambiguities, which is even harder when you're moving (ie, a missile) and even harder when you're moving fast. And should a cycle slip occure, you have to start all over again, not something very practicle for a missile. (for the laymen: phase tracking is only useful when the number of frequency cycles between the receiver and the satellite are known. When this isn't known, there isn't nearly as much of an advantage)
Also, AFAIK GPS can be selectively turned on and off over a given region, either by turning off L1 (the civilian frequency) or both L1 and L2 (unlikely to ever happen). If they were to turn L1 off, any civilian receiver in the area would be useless, even top-of-the line civilian Trimbles. On the plus side, they can also turn the y-code encryption off on L2, like they did in Gulf War 1 (they didn't have enough military receivers at the time).
Of course, GPS isn't the only way to have precision munitions. In Gulf War 1, most of the munitions dropped by the US were laser-guided.
Others already mentioned that the standard GPS constellation is at a mid-level orbit (about 20,000km altitude). In addition, there are two GPS satellites in geosynchronous orbit, providing WAAS coverage. While they are fixed in the sky, they are still going in circles about the Earth with a period of 24 hours.
Well, the US government has massive reserves of oil for emergency purposes. A more likely scenario would be another Arab oil embargo like in the 70s. While it would greatly inconvenience many people, there wouldn't be mass starvation or anything like that. There's still untapped reserves in Alaska that could be used in an emergency, so it's pretty inconceivable that the US could suddenly be without even enough oil to ship food from farms to cities.
That'd be a clever way of taking care of a cat in one try. *rim shot*