OSC doesn't do new stuff. Almost all of his books is a retelling of (his) Mormon values. They tend to start with a very good book or two (i.e., the fist two books in Ender or Homecoming series) and then rapidly disintegrate into fairly banal family and religious values only he and his religious friends could believe in. On the other hand, he is a very good writer and writes very convincingly, even I can't stand his values and religion, I find myself reading even his worst books. I always kick myself after finishing an other one of his pretentious shit and wow to myself "never again".
Well, suddenly I remembered good old HAARP project which is simply a HF transmitter with a whopping almost 4000MW of power (when/if it is finished(unless it is already finished))!
Also there are phase-array antenna systems like the old Russian Woodpecker but I'm not sure about that one's output.
Ham radio usually uses miniscule amount of transmission power compared to commercial and military HF/VHF/UHF operators but still a lot more than unlicensed operators (4W for CB, ~0.1-0.25W for WiFi. I can legally use 400W transmitters in 2.4GHz band and since I am the primary operator, no one can complain about my powerful signal wrecking their WiFi networks.:)
In UK, I am limited with 400W PEP. In USA if I'm not mistaken you can go upto kW range but the cost increases as well. You can buy a 200W PEP HF tranceiver for about a couple of grand, I got mine (100W for HF, 50 for UHF/VHF) for about 1.2 grand but mine also has additional satellite functionality.
These days almost any non-space-based scientifict project is cheaper than a figher jet.
Like Deep Space-1? That thing had failures in almost all demonstrator components but it still went on and on. What about the two rovers in Mars? They lost wheels, got stuck in dunes and their solar panels got covered with lots of dirt but Americans didn't just turn them off.
I think you have a maligned view of scientists worldwide.
Isn't it ironic that both programs were designed and launched in the era of "faster-better-cheaper" Daniel Goldin and were incredibly successful? Now under Bush, Americans are killing their space-science program, effectively killing ISS and just sinking money reinventing what they and soviets did 40 years ago. Chinese are starting from scratch and they are already ahead of Americans, at least they can launch people to space themselves.
I'm not optimistic. They can't point the craft accurately anymore, they used too much fuel trying to station-keep above the asteroid because the gyros weren't functioning. For the same reason (using rockets for attitute cost them the probe because they didn't know exactly what they were doing. The mission is a loss from this point onwards but still it is a success with what they have done so far. NASA managed to use DS-1 in a similar situation for quite a long time but DS-1 was always a technology demonstrator, a spacecraft without a real mission and everything was just an opportunity and what a success it was.
As far as I'm concerned, they have succeeded with this probe. Let alone catching with this asteroid was quite a success for Japanese. Don't forget that the first one was the a href="http://en.wikipedia.org/wiki/NEAR_Shoemaker" >NEAR probe and that had its mistfortunes as well (like the first attempt to get into the right orbit failed and they had to wait two more years). This is as successful as NEAR and was more ambitious and was much cheaper (NEAR costed about $150M, I can't find the exact figure for Hayabusa at the moment). Go go Maginger!! Ah, were was I? Ah, yes, I think it's a good result for JAXA. Three cheers! Huzzah! Huzzah! Huzzah!
I may be an AC, but I'm also a RA I strongly doubt this because a RA wouldn't say things like: The telescope is 50 m diameter, so to get it to slew fast enough to track anything other than a relatively geostationary satellitebecause it is pure bollocks. I bet you haven't operated anything bigger than a motorized 4" telescope in your back yard. 50m dish is nothing and with enough motors with the correct gear train you can track any satellite. You might not be able to track a plane flying overhead but it is quite obvious that you never tracked a satellite. I have, both with a telescope and with a radio antenna in my hand.
And let's have a look at this:
Some day they might apply the same "adaptive optics" focusing systems on a space or airplane based platform
Adaptive focus... In a radio telescope?? What are you smoking, it must be truly good stuff!
With parabolic mirrors you are focusing wtr to the mirror's focal length. Radio signals do not have to be "in focus" as such and almost anything can be considered at infinity, especially compared to the mirror's size and focal length. Don't forget that the dish is just a big mirror. You can set your telescope to infinity and will be able to resolve aircraft at 10km away, satellites at 200 and moon at 350000 km. The dish's focal length is tiny compared to the distances. The only fine tuning you might like to do is due to the metal length differences in different temperatures. Otherwise you can just bolt the tranceiver and be done with it. Worse, radio signals do not get refracted with the air turbulance in the same order of magnitude as the light signals do. I can clearly see that you have no idea what "adaptive optics" means. Here is the definition for you.
And lastly, it doesn't matter how much energy you put into your transmitter, you are not going to fry the satellite's electronics. That's just pure bollocks. I can use a 100W transmitter just next to my UHF receiver and my receiver will not get damaged. And that's with a meter difference. At 250km away the signal will be sqr(250*1000) time smaller and to have the same flux through the antenna I have to put out sqr(250*1000)*100W power and still the tranceiver will not be damaged!
That's not news. American DoD always in favour of putting weapons in space. Don't forget that until Apollo, American astronauts rode rockets designed to hurl nuclear bombs to russia. Titan II was a very high performance American Air Force ICBM. Atlas was a revolutionary ICBM. Jupiter was an IRBM and placed the first american satellite and it was built for and operated by American Air Force as well.
A radio telescope is something with an antenna (the dish) and a receiver.
A RADAR is something with an antenna (the dish) and a transmitter/receiver pair (commonly known as tranceiver).
Now, spot the similarity... You can't add a telescope feature to a radar dish, it is inherently built-in. You just choose not to transmit. You can have a radio telescope and a radar without the dish but you always will have a receiver and an antenna involved in both.
You are not that far away from the truth. Signals like radio waves follow square law which means to double the signal you have to quadrouple the power. Also the disk is nothing but a parabolic mirror. As opposed to light waves, doing interferometres out of radio telescopes is easier, because of the larger wavelength. 1mm might be small but it is much much larger than 400-700 nanometers which is the visible light. As a result timing of the signals can be calculated easier and that's why radio astronomers build things like VLBA. Large dishes like Arecibo were designed and built well before VLBA and not a lot of people build massive and inflexible telescopes like that, any more. Low-cost designs like One Hectare Telescope are designs just like you mentioned. The problem with such systems is the cost of the (many) receivers and transmitters, a typical reasonably good quality ham radio HF tranceiver costs around 1000 pounds, ten thousands of these will mean the experiment suddenly got far too expensive.
You must realise that because of radio wave's probogation mechanism, it is one of the worst way of transferring energy. A LASER is always more efficient, a MASER would be better but they tend to be a lot less powerful. To make a sattellite inoperative, the best way is just jamming it. Most communication satellites are just simple repeaters (transponders) in space where they repeat incoming signal at an other frequency and other dish. Garbage in and garbage out, your satellite no longer works reliably.
Almost all radio telescopes can transmit as well as receive. The main cost is not the transmitter, it is usually the reciever and structural/land/engineering costs and it always pays to have a transmitter. OTOH, I bet a pringles can do the job as well, see other slashdot stories for today, Pringles cans can be used to solve all problems!
These days I only shop for used film equipment in ebay, because of the digital revolution the bottom has fallen off in the film market; 35mm cameras can be purchased dirt cheap. I think I will go on using film as well as digital until they stop making the films (probably we will get there within 5 years). The idea is not a bad one but his choice of camera is just so wrong. As you said you just don't want to get that equipment oily - yet. When the next Canon 18Mpixel camera becomes 500 pounds, then you really can afford to experiment with it. I have an old Yashica on my desk with a CCD sitting next to it. One evening I will have some free time and do a little bit of mod work to see what I can do with it.:) OTOH, I can always stop reading/. and get the screwdrivers... Hey! That's an idea!:) Doing something useful instead of posting at/.! Naah, can't be bothered with it...
Well, since you are not connecting the lens directly to the camera, any cheap 35mm camera lens will work. Out of current Ebay-UK, take this cheap lens, which with the current going price will cost 3 pounds (about 5 euros/dollars) inc. p&p. Now your cost is slightly higher. Unless you buy a expensive DSLR, you can go even cheaper by getting something like a second hand Praktica MTL SLR which I personally have one and in the past bought a couple and handed to friends (because they are truly reliable and wonderful cameras) and the usual going rate is around 5-10 pounds plus p&p. Now that's cheap. Usually they come with a 50 or 58mm russian/east-european lens and they are good enough to be abused in any way. Now, considering all these, trying one of these mods won't make you destitute. You can increase the bid by modding the camera to hold a CCD inside. Now that'd be a good project wouldn't it?
These kinds of extension tubes are quite common things, and cheap. I have a number of them for my M42 mount cheap-ass Praktika camera. I think they cost about 2 pounds overall. The guy has a D20, if he is rich enough to pay for that camera, he should ne able to afford a proper and good macro lens. Extension tubes are a pain when you are holding the camera and trying to focus but they are cheap alternatives for the real thing. I think the correct terminology is bellows or something like that. I have the stuff lying around but never bothered the learn the correct terminology.:)
Obvious, When you believe in Jesus (aka Aslan), you can kill without shedding blood ('cause Jesus/Aslan died for your sins). I like japanese movies just for this reason, they are bloody, sooo bloody that it stops being real and start being comical (just like Kill Bill emulated). Ichi the Killer was some violent movie but it was so surreal, you can probably watch it from start to end without retching.
And what's stopping you from dying after you are 21? I'm happy that I managed to survive those three very dangerous years, drinking as the usual amount for a university student. I think Americans got this wrong, quite wrong. Now I drink a lot less, work life is less stressful than university life. It's down to a pint or two once in a while at the pub on a friday lunchtime.
if you're a couch potato, suddenly becoming active may be harder than you think Tell me something I don't know. Anyone who has gone through an overweight period can tell you this.
Well, you see, there was this movie called Waterworld with Kevin Something in it. Probably that made a deep(!) impression(!) on his mind. Don't be so harsh.
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OSC doesn't do new stuff. Almost all of his books is a retelling of (his) Mormon values. They tend to start with a very good book or two (i.e., the fist two books in Ender or Homecoming series) and then rapidly disintegrate into fairly banal family and religious values only he and his religious friends could believe in. On the other hand, he is a very good writer and writes very convincingly, even I can't stand his values and religion, I find myself reading even his worst books. I always kick myself after finishing an other one of his pretentious shit and wow to myself "never again".
Also there are phase-array antenna systems like the old Russian Woodpecker but I'm not sure about that one's output.
Ham radio usually uses miniscule amount of transmission power compared to commercial and military HF/VHF/UHF operators but still a lot more than unlicensed operators (4W for CB, ~0.1-0.25W for WiFi. I can legally use 400W transmitters in 2.4GHz band and since I am the primary operator, no one can complain about my powerful signal wrecking their WiFi networks. :)
These days almost any non-space-based scientifict project is cheaper than a figher jet.
I think you have a maligned view of scientists worldwide.
Isn't it ironic that both programs were designed and launched in the era of "faster-better-cheaper" Daniel Goldin and were incredibly successful? Now under Bush, Americans are killing their space-science program, effectively killing ISS and just sinking money reinventing what they and soviets did 40 years ago. Chinese are starting from scratch and they are already ahead of Americans, at least they can launch people to space themselves.
I'm not optimistic. They can't point the craft accurately anymore, they used too much fuel trying to station-keep above the asteroid because the gyros weren't functioning. For the same reason (using rockets for attitute cost them the probe because they didn't know exactly what they were doing. The mission is a loss from this point onwards but still it is a success with what they have done so far. NASA managed to use DS-1 in a similar situation for quite a long time but DS-1 was always a technology demonstrator, a spacecraft without a real mission and everything was just an opportunity and what a success it was.
Use the preview button, Luke... NEAR...
As far as I'm concerned, they have succeeded with this probe. Let alone catching with this asteroid was quite a success for Japanese. Don't forget that the first one was the a href="http://en.wikipedia.org/wiki/NEAR_Shoemaker" >NEAR probe and that had its mistfortunes as well (like the first attempt to get into the right orbit failed and they had to wait two more years). This is as successful as NEAR and was more ambitious and was much cheaper (NEAR costed about $150M, I can't find the exact figure for Hayabusa at the moment). Go go Maginger!! Ah, were was I? Ah, yes, I think it's a good result for JAXA. Three cheers! Huzzah! Huzzah! Huzzah!
Of course aliens are involved with it. ET just wants to phone home but this time he doesn't want any line static.
I strongly doubt this because a RA wouldn't say things like:
The telescope is 50 m diameter, so to get it to slew fast enough to track anything other than a relatively geostationary satellitebecause it is pure bollocks. I bet you haven't operated anything bigger than a motorized 4" telescope in your back yard. 50m dish is nothing and with enough motors with the correct gear train you can track any satellite. You might not be able to track a plane flying overhead but it is quite obvious that you never tracked a satellite. I have, both with a telescope and with a radio antenna in my hand.
And let's have a look at this:
Some day they might apply the same "adaptive optics" focusing systems on a space or airplane based platform
Adaptive focus... In a radio telescope?? What are you smoking, it must be truly good stuff!
With parabolic mirrors you are focusing wtr to the mirror's focal length. Radio signals do not have to be "in focus" as such and almost anything can be considered at infinity, especially compared to the mirror's size and focal length. Don't forget that the dish is just a big mirror. You can set your telescope to infinity and will be able to resolve aircraft at 10km away, satellites at 200 and moon at 350000 km. The dish's focal length is tiny compared to the distances. The only fine tuning you might like to do is due to the metal length differences in different temperatures. Otherwise you can just bolt the tranceiver and be done with it.
Worse, radio signals do not get refracted with the air turbulance in the same order of magnitude as the light signals do. I can clearly see that you have no idea what "adaptive optics" means. Here is the definition for you.
And lastly, it doesn't matter how much energy you put into your transmitter, you are not going to fry the satellite's electronics. That's just pure bollocks. I can use a 100W transmitter just next to my UHF receiver and my receiver will not get damaged. And that's with a meter difference. At 250km away the signal will be sqr(250*1000) time smaller and to have the same flux through the antenna I have to put out sqr(250*1000)*100W power and still the tranceiver will not be damaged!
That's not news. American DoD always in favour of putting weapons in space. Don't forget that until Apollo, American astronauts rode rockets designed to hurl nuclear bombs to russia. Titan II was a very high performance American Air Force ICBM. Atlas was a revolutionary ICBM. Jupiter was an IRBM and placed the first american satellite and it was built for and operated by American Air Force as well.
A radio telescope is something with an antenna (the dish) and a receiver.
A RADAR is something with an antenna (the dish) and a transmitter/receiver pair (commonly known as tranceiver).
Now, spot the similarity...
You can't add a telescope feature to a radar dish, it is inherently built-in. You just choose not to transmit. You can have a radio telescope and a radar without the dish but you always will have a receiver and an antenna involved in both.
You are not that far away from the truth. Signals like radio waves follow square law which means to double the signal you have to quadrouple the power. Also the disk is nothing but a parabolic mirror. As opposed to light waves, doing interferometres out of radio telescopes is easier, because of the larger wavelength. 1mm might be small but it is much much larger than 400-700 nanometers which is the visible light. As a result timing of the signals can be calculated easier and that's why radio astronomers build things like VLBA.
Large dishes like Arecibo were designed and built well before VLBA and not a lot of people build massive and inflexible telescopes like that, any more.
Low-cost designs like One Hectare Telescope are designs just like you mentioned. The problem with such systems is the cost of the (many) receivers and transmitters, a typical reasonably good quality ham radio HF tranceiver costs around 1000 pounds, ten thousands of these will mean the experiment suddenly got far too expensive.
You must realise that because of radio wave's probogation mechanism, it is one of the worst way of transferring energy. A LASER is always more efficient, a MASER would be better but they tend to be a lot less powerful. To make a sattellite inoperative, the best way is just jamming it. Most communication satellites are just simple repeaters (transponders) in space where they repeat incoming signal at an other frequency and other dish. Garbage in and garbage out, your satellite no longer works reliably.
Almost all radio telescopes can transmit as well as receive. The main cost is not the transmitter, it is usually the reciever and structural/land/engineering costs and it always pays to have a transmitter.
OTOH, I bet a pringles can do the job as well, see other slashdot stories for today, Pringles cans can be used to solve all problems!
What I want to know is why you don't know what you want when you are ordering drinks at the theatre? Always a pint of bitter, please, always...
These days I only shop for used film equipment in ebay, because of the digital revolution the bottom has fallen off in the film market; 35mm cameras can be purchased dirt cheap. I think I will go on using film as well as digital until they stop making the films (probably we will get there within 5 years). :) /. and get the screwdrivers... Hey! That's an idea! :) Doing something useful instead of posting at /.!
The idea is not a bad one but his choice of camera is just so wrong. As you said you just don't want to get that equipment oily - yet. When the next Canon 18Mpixel camera becomes 500 pounds, then you really can afford to experiment with it.
I have an old Yashica on my desk with a CCD sitting next to it. One evening I will have some free time and do a little bit of mod work to see what I can do with it.
OTOH, I can always stop reading
Naah, can't be bothered with it...
I find religion and religious nutters offensive to my tastes and ideas. So what? What about my feelings and rights?
Also the can can be used as a waveguide which extends the WiFi signal range quite spectacularly.
Well, since you are not connecting the lens directly to the camera, any cheap 35mm camera lens will work.
Out of current Ebay-UK, take this cheap lens, which with the current going price will cost 3 pounds (about 5 euros/dollars) inc. p&p. Now your cost is slightly higher. Unless you buy a expensive DSLR, you can go even cheaper by getting something like a second hand Praktica MTL SLR which I personally have one and in the past bought a couple and handed to friends (because they are truly reliable and wonderful cameras) and the usual going rate is around 5-10 pounds plus p&p. Now that's cheap. Usually they come with a 50 or 58mm russian/east-european lens and they are good enough to be abused in any way.
Now, considering all these, trying one of these mods won't make you destitute. You can increase the bid by modding the camera to hold a CCD inside. Now that'd be a good project wouldn't it?
These kinds of extension tubes are quite common things, and cheap. I have a number of them for my M42 mount cheap-ass Praktika camera. I think they cost about 2 pounds overall. :)
The guy has a D20, if he is rich enough to pay for that camera, he should ne able to afford a proper and good macro lens. Extension tubes are a pain when you are holding the camera and trying to focus but they are cheap alternatives for the real thing. I think the correct terminology is bellows or something like that. I have the stuff lying around but never bothered the learn the correct terminology.
Obvious, When you believe in Jesus (aka Aslan), you can kill without shedding blood ('cause Jesus/Aslan died for your sins).
I like japanese movies just for this reason, they are bloody, sooo bloody that it stops being real and start being comical (just like Kill Bill emulated). Ichi the Killer was some violent movie but it was so surreal, you can probably watch it from start to end without retching.
And what's stopping you from dying after you are 21?
I'm happy that I managed to survive those three very dangerous years, drinking as the usual amount for a university student. I think Americans got this wrong, quite wrong.
Now I drink a lot less, work life is less stressful than university life. It's down to a pint or two once in a while at the pub on a friday lunchtime.
dammit, where are the bloody mod points when I need them.
if you're a couch potato, suddenly becoming active may be harder than you think
Tell me something I don't know. Anyone who has gone through an overweight period can tell you this.
Well, you see, there was this movie called Waterworld with Kevin Something in it. Probably that made a deep(!) impression(!) on his mind. Don't be so harsh.