They're not talking about putting it in orbit around the moon, they want to put it ON the moon. Also, off the top of my head without doing any math, I'd guess that a "lunosynchronous" orbit would be impossible, I think the orbital radius would be the same as the distance to the earth...
It's better because it puts the mass of the moon in between itself and all the radio noise of earth. Also, the reason it's called the "dark side of the moon" is that it ALWAYS faces away from earth. That's the whole reason for putting it there. That does make communicating with it more dificult though, it would need either relay sattelites orbiting the moon, or a relay station on the side facing us connected by cable.
I don't think "propagate" is the right word. This virus has no way to spread other than people copying infected binaries from system to system and running them as root. I don't know about you, but that's not something I ever do. The only way a linux virus is ever going to do damage is if it gets into a package on a major distro's ftp and goes unnoticed.
If someone wanted to hide a message in images on newsgroups, they wouldn't put a plaintext msg that any newb running a dictionary based attack could find, unless they wanted it to be found. It would be trivial to add one more step of xor'ing the msg with a random key first, then putting the key in a second image, or evern better sending it through another conduit. I know if I was going to use something as lame as stenography to send an important msg, I would go to the trouble of not sending plaintext.
Maybe sharks don't get cancer because they ARE fighting it. I'm not going to take the time to look up a sharks life span, but I'd be willing to bet it's less than a human's life span, and for reasons unrelated to this research.
The solar foci telescope idea sounds really cool, but it's got a big limitation. It can only see in 1 direction. With a 450au orbit, its orbital period is around 9500 years. That means it will only move 0.037 degrees through it's orbit every year. And assuming it won't be carrying the fuel to make huge orbital adjustments, it will only be able to view along the plane of it's orbit. We would have to have a good dense area of sky to view before launching something like that.:)
The solar foci telescope idea sounds really cool, but it's got a big limitation. It can only see in 1 direction. With a 450au orbit, its orbital period is around 9500 years. That means it will only move 0.037 degrees through it's orbit every year. And assuming it won't be carrying the fuel to make huge orbital adjustments, it will only be able to view along the plane of it's orbit. We would have to have a good dense area of sky to view before launching something like that.:)
Jupiter and saturn are almost always visible with the naked eye, the only thing really notworthy is that saturn is at maximum tilt with respect to earth, giving the best view of the rings. This will last a while fortunatly, but once it's gone it'll be a while before it happens again. IIRC, Saturn's orbit is something like 250 years.
Re:I think people are making this more difficult..
on
Flying on Mars
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· Score: 3, Informative
I hate to nitpick, but this is so wrong I had to point it out.
Taking the difference, we find that there is 115.5x10^5 grams or...
11550 kg of lifting force here.. ...
Now, can we build an airship of that size and keep it's weight under 10000 kg? (Mind you that IS 30000kg here on earth)...
I'll assume based on the rest of the post that you know the difference between mass and weight...;)
10000kg on earth is still 10000kg on mars.
Other than that and the fact that some of the calculations you show have the wrong answer (but strangely the right final answer, where'd you pull that out of?), you're right, a blimp should work ok on mars.
I don't agree however that you could cancel the effect out by timing the subsequent launches. The issue of total angular momentum needs to be addressed. Subsequent launches could only cancel the angular momentum if they were somehow launched from the end of the cable with opposite angular momentum.
I think you misunderstood what I meant. The cable would lean west (very slightly) during a launch, and once the payload finished its ascent, the cable would swing back towards vertical. If left alone at this point, it would continually swing back and forth. It's not the transfer of angular momentum away from earth that I was talking about cancelling, it's the swinging of the cable. If you time your launches so that they occur while the cable is swinging back east, the eastward momentum would be canceled out by the westward momentum that the cable gains from the cargo.
As for why it would swing like a pendulum, I'll try to explain the best I can without drawing pictures.:) As long as the cable is leaning westward, the cable will be gaining eastward angular momentum from the earth. This is simply because the cable is under tension and no longer perpendicular to the orbit. Likewise, when it leans east, the cable tension will have a westward component pulling on the counterweight. As the cable swings back and forth, the angular momentum of the whole system (earth, cable, counterweight) will remain the same, but a small amount of the momentum will slowly transfer back and forth between earth and counterweight.
Well the angular momentum isn't free, it's taken away from earth's angular momentum. If we were to launch a significant percent of earth's mass this way, we could make a day longer. That would require billions of launches though, so i don't think it's a problem.:)
The reason it won't wrap itself around earth is that the counterweight at the end of the cable is not in orbit, it's actually moving faster than the orbital speed and being pulled centripitally by the cable. I'm not sure how many g's it would be pulling, but you should be able to stand on it and look up at earth. And since the g force is in the direction perpendicular to the earth at the anchor point, whenever it swung away from vertical there would be a component of the cable's tension pulling it back towards vertical again. Hense, a giant pendulum.
With the huge length of the cable and mass at the end of it, the period of the pendulum would be pretty long probably. In order to have the launches cancel out each other's effect on the cable, the launch frequency would have to be a multiple of the period of the swing. Maybe that's how they came up with the 97 hours between launches?
I'm a little drunk so ignore me if i make no sense. I would think that every object that climbs the cable would impart angular momentum on the cable in the direction opposite the rotation of earth. The mass of a single "launch" would be miniscule compared to the total mass of the cable and counterweight, so it wouldn't cause much motion in the cable. Since the cable is essentially hanging like a giant pendulum off the earth, the "top" end of it would slowly swing back and forth in orbit. All you have to do to stop each launch from adding to the motion of the cable, is to time each launch to coincide with the cable swinging in the opposite direction the momentum that the launch will give it.
That's true, but unless it jumps up and says "Hi!", we have no way to look for it. If non carbon/water based life is found, it's unlikely to be on purpose, it will most likely be while we're looking for something else. In the meantime, we will continue to look for signs of life in places that make sense based on what we do know.
Well with titles like "Canadian Researchers Create Supernova In-lab" which are completely untrue, it's easy to see how someone uneducated in the field might be confused.
The reason everyone is laughing at this, is because for $1500 you could build a pc with a couple hundred gigs, a soundcard with optical out to interface nicely with your stereo, a 15" lcd to display whatever the hell you want, 100Mbit, tvout, IR remote, etc, etc, etc. All that would be well under $1500. The only thing missing is a nice software package that has all the features, although there are individual packages to do everything except the playlist suggestion crap.
The problem is, the ion drive isn't designed for orbital manuvering. It's thrust is very weak, and takes a while to make any course adjustments. Getting it into orbit around earth might be possible, but getting it into a stable low orbit so that the shuttle could pick it up would be a long, tedious (and expensive) process.
Also, shuttles up there currently have nothing to do with it, since it would take quite a while for it to get back to earth anyway.
Of course I'm just talking out of my ass, so ignore me if I'm completely wrong.
I'm pretty sure an ion drive can't pump out particles at 0.999 lightspeed. The accelerators we have that do this are huge rings with circumfrences measured in kilometers, and they accelerate tiny amounts of matter even compared to the ion engine. The top speed on something driven by one might be 0.999 lightspeed, but it would take billions of years to get up to speed.
And if we wanted to go back, we could put a man on the moon cheaper and faster now than we could in the 60's. We haven't gone back because there hasn't been a good enough reason, it has nothing to do with the technology. We only went in the first place for bragging rights vs Russia. Until we plan on building a colony or a solar power plant or something big there, there's no real need to send astronauts.
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They're not talking about putting it in orbit around the moon, they want to put it ON the moon. Also, off the top of my head without doing any math, I'd guess that a "lunosynchronous" orbit would be impossible, I think the orbital radius would be the same as the distance to the earth...
It's better because it puts the mass of the moon in between itself and all the radio noise of earth. Also, the reason it's called the "dark side of the moon" is that it ALWAYS faces away from earth. That's the whole reason for putting it there. That does make communicating with it more dificult though, it would need either relay sattelites orbiting the moon, or a relay station on the side facing us connected by cable.
They're not? Then why do they feel the need to keep pointing out that *bsd can run linux binaries?
I don't think "propagate" is the right word. This virus has no way to spread other than people copying infected binaries from system to system and running them as root. I don't know about you, but that's not something I ever do. The only way a linux virus is ever going to do damage is if it gets into a package on a major distro's ftp and goes unnoticed.
If someone wanted to hide a message in images on newsgroups, they wouldn't put a plaintext msg that any newb running a dictionary based attack could find, unless they wanted it to be found. It would be trivial to add one more step of xor'ing the msg with a random key first, then putting the key in a second image, or evern better sending it through another conduit. I know if I was going to use something as lame as stenography to send an important msg, I would go to the trouble of not sending plaintext.
Maybe sharks don't get cancer because they ARE fighting it. I'm not going to take the time to look up a sharks life span, but I'd be willing to bet it's less than a human's life span, and for reasons unrelated to this research.
The solar foci telescope idea sounds really cool, but it's got a big limitation. It can only see in 1 direction. With a 450au orbit, its orbital period is around 9500 years. That means it will only move 0.037 degrees through it's orbit every year. And assuming it won't be carrying the fuel to make huge orbital adjustments, it will only be able to view along the plane of it's orbit. We would have to have a good dense area of sky to view before launching something like that. :)
The solar foci telescope idea sounds really cool, but it's got a big limitation. It can only see in 1 direction. With a 450au orbit, its orbital period is around 9500 years. That means it will only move 0.037 degrees through it's orbit every year. And assuming it won't be carrying the fuel to make huge orbital adjustments, it will only be able to view along the plane of it's orbit. We would have to have a good dense area of sky to view before launching something like that. :)
I don't know who's ass i pulled that number out of, Saturn's orbit is only 29 years.
Jupiter and saturn are almost always visible with the naked eye, the only thing really notworthy is that saturn is at maximum tilt with respect to earth, giving the best view of the rings. This will last a while fortunatly, but once it's gone it'll be a while before it happens again. IIRC, Saturn's orbit is something like 250 years.
I hate to nitpick, but this is so wrong I had to point it out.
...
;)
10000kg on earth is still 10000kg on mars.
Taking the difference, we find that there is 115.5x10^5 grams or...
11550 kg of lifting force here..
Now, can we build an airship of that size and keep it's weight under 10000 kg? (Mind you that IS 30000kg here on earth)...
I'll assume based on the rest of the post that you know the difference between mass and weight...
Other than that and the fact that some of the calculations you show have the wrong answer (but strangely the right final answer, where'd you pull that out of?), you're right, a blimp should work ok on mars.
That first paragraph was supposed to be in tags, guess that will teach me to not preview first :)
I don't agree however that you could cancel the effect out by timing the subsequent launches. The issue of total angular momentum needs to be addressed. Subsequent launches could only cancel the angular momentum if they were somehow launched from the end of the cable with opposite angular momentum.
:) As long as the cable is leaning westward, the cable will be gaining eastward angular momentum from the earth. This is simply because the cable is under tension and no longer perpendicular to the orbit. Likewise, when it leans east, the cable tension will have a westward component pulling on the counterweight. As the cable swings back and forth, the angular momentum of the whole system (earth, cable, counterweight) will remain the same, but a small amount of the momentum will slowly transfer back and forth between earth and counterweight.
I think you misunderstood what I meant. The cable would lean west (very slightly) during a launch, and once the payload finished its ascent, the cable would swing back towards vertical. If left alone at this point, it would continually swing back and forth. It's not the transfer of angular momentum away from earth that I was talking about cancelling, it's the swinging of the cable. If you time your launches so that they occur while the cable is swinging back east, the eastward momentum would be canceled out by the westward momentum that the cable gains from the cargo.
As for why it would swing like a pendulum, I'll try to explain the best I can without drawing pictures.
Well the angular momentum isn't free, it's taken away from earth's angular momentum. If we were to launch a significant percent of earth's mass this way, we could make a day longer. That would require billions of launches though, so i don't think it's a problem. :)
The reason it won't wrap itself around earth is that the counterweight at the end of the cable is not in orbit, it's actually moving faster than the orbital speed and being pulled centripitally by the cable. I'm not sure how many g's it would be pulling, but you should be able to stand on it and look up at earth. And since the g force is in the direction perpendicular to the earth at the anchor point, whenever it swung away from vertical there would be a component of the cable's tension pulling it back towards vertical again. Hense, a giant pendulum.
With the huge length of the cable and mass at the end of it, the period of the pendulum would be pretty long probably. In order to have the launches cancel out each other's effect on the cable, the launch frequency would have to be a multiple of the period of the swing. Maybe that's how they came up with the 97 hours between launches?
I'm a little drunk so ignore me if i make no sense. I would think that every object that climbs the cable would impart angular momentum on the cable in the direction opposite the rotation of earth. The mass of a single "launch" would be miniscule compared to the total mass of the cable and counterweight, so it wouldn't cause much motion in the cable. Since the cable is essentially hanging like a giant pendulum off the earth, the "top" end of it would slowly swing back and forth in orbit. All you have to do to stop each launch from adding to the motion of the cable, is to time each launch to coincide with the cable swinging in the opposite direction the momentum that the launch will give it.
I think that makes sense.
That's true, but unless it jumps up and says "Hi!", we have no way to look for it. If non carbon/water based life is found, it's unlikely to be on purpose, it will most likely be while we're looking for something else. In the meantime, we will continue to look for signs of life in places that make sense based on what we do know.
Well with titles like "Canadian Researchers Create Supernova In-lab" which are completely untrue, it's easy to see how someone uneducated in the field might be confused.
The reason everyone is laughing at this, is because for $1500 you could build a pc with a couple hundred gigs, a soundcard with optical out to interface nicely with your stereo, a 15" lcd to display whatever the hell you want, 100Mbit, tvout, IR remote, etc, etc, etc. All that would be well under $1500. The only thing missing is a nice software package that has all the features, although there are individual packages to do everything except the playlist suggestion crap.
IIRC, that 0.05 AU is in regards to long term danger, not a danger on this orbit.
The problem is, the ion drive isn't designed for orbital manuvering. It's thrust is very weak, and takes a while to make any course adjustments. Getting it into orbit around earth might be possible, but getting it into a stable low orbit so that the shuttle could pick it up would be a long, tedious (and expensive) process.
Also, shuttles up there currently have nothing to do with it, since it would take quite a while for it to get back to earth anyway.
Of course I'm just talking out of my ass, so ignore me if I'm completely wrong.
It's most likely millions of dollars and a dish (or array of dishes) the size of a stadium.
I'm pretty sure an ion drive can't pump out particles at 0.999 lightspeed. The accelerators we have that do this are huge rings with circumfrences measured in kilometers, and they accelerate tiny amounts of matter even compared to the ion engine. The top speed on something driven by one might be 0.999 lightspeed, but it would take billions of years to get up to speed.
And if we wanted to go back, we could put a man on the moon cheaper and faster now than we could in the 60's. We haven't gone back because there hasn't been a good enough reason, it has nothing to do with the technology. We only went in the first place for bragging rights vs Russia. Until we plan on building a colony or a solar power plant or something big there, there's no real need to send astronauts.
Not likely, unless your linux box is a powerpc like the tivo, has the same mpeg chips, etc.
And I feel even stupider for having read about you feeling stupider for having read the stupid review.
Why am I posting this, this is stupid.