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How do you know if you're dating a physics major?
Hand-shaped chalk impressions on yer arse.
but seriously.
Chalk Mk 3 is an interesting kind of mission, and the PvP is exciting and skillbased! Make sure you up faction!
ok, ACTUALLY seriously,
I thought tachyons were more or less dropped. Do they appear in any leading theories right now? Weren't they just invented as a way to fudge the Feynmann diagrams?
But solar sails are all good. They won't help you escape causality though, you need some crazy exotic material for that.
Hand-shaped chalk impressions on yer arse.
but seriously.
Chalk Mk 3 is an interesting kind of mission, and the PvP is exciting and skillbased! Make sure you up faction!
ok, ACTUALLY seriously,
I thought tachyons were more or less dropped. Do they appear in any leading theories right now? Weren't they just invented as a way to fudge the Feynmann diagrams?
But solar sails are all good. They won't help you escape causality though, you need some crazy exotic material for that.
'haps you could d make the sail this way.
First for the main part of the sail it would be made of a rubber that is compltely unaffected by any electrical currunt and is de singed to withstand dramatic temperature changes.On top of it, it has fine wires runing along its surface.These wires collect the tachyons and convert them to link up with an electric current, by means of magnetics.The wires go into hollow "veins" that run below the rubber surface these viens convey quicksilver.The electrons are carried with the quicksilverto the rest of the magnetics that change the electrons to the feul of the ion drive. and that would make sense cuase the wires could be the positve side while the quicksilver could be the negative side.
First for the main part of the sail it would be made of a rubber that is compltely unaffected by any electrical currunt and is de singed to withstand dramatic temperature changes.On top of it, it has fine wires runing along its surface.These wires collect the tachyons and convert them to link up with an electric current, by means of magnetics.The wires go into hollow "veins" that run below the rubber surface these viens convey quicksilver.The electrons are carried with the quicksilverto the rest of the magnetics that change the electrons to the feul of the ion drive. and that would make sense cuase the wires could be the positve side while the quicksilver could be the negative side.
Ok, maybe thats a bit farfetched...
Truly. To begin with, it was never postulated that tachyons would be able to travel by wire. We'll just stop there...
well you wouldn't nesesarily need tachions to sail faster than the speed of light. Provided solar sails work anything like their namesake (that may be too big an assumption) they could sail faster than the wind in the same way sailboats do, by using galaleian (sp) relativity and vectors.
all you need is something to do the job of a centerboard (probably something similar to the gravitic drive used by the ships in VO) and then by sailing on a close reach (about 50 drgees off the wind).
now this may brake down under einsteinian relativity, but as long as the ship is still accelerating ti should be ok.
all you need is something to do the job of a centerboard (probably something similar to the gravitic drive used by the ships in VO) and then by sailing on a close reach (about 50 drgees off the wind).
now this may brake down under einsteinian relativity, but as long as the ship is still accelerating ti should be ok.
You'll want to look up those earlier links I posted. It doesn't work like that. In fact, solar sails don't have anything to do with solar winds.
I thought they invented tachyons as FTL messenger particles in an attempt to explain the whole "Spooky action at a distance" twin-particles with opposite spin thing? (When one particle is observed to have spin "x", the other twin particle resolves at the same time to have spin "-x", even if the other particle is on the other side of the universe. How does it know?) Anyway...
Don't solar sails just use the pressure of lightwaves/photons to continuously accelerate away from a lightsource? You can give it a boost by shooting lasers at it, but otherwise it relies on the (weak) power of the nearest star.
The Planetary Society launched a solar sail, but something broke on it this summer I think.
Don't solar sails just use the pressure of lightwaves/photons to continuously accelerate away from a lightsource? You can give it a boost by shooting lasers at it, but otherwise it relies on the (weak) power of the nearest star.
The Planetary Society launched a solar sail, but something broke on it this summer I think.
there are probably several kinds of solar sails, the original adea was something like what Leber and i are thinking of. but who knows what other crazy ideas have been called solar sails (retoricle question).
also i've heard all kinds of wacky explenation about what tachions are, honestl;y i thought Star trek made them up and then physisists named something they found later after them, but that may just be based in my own insanity.
also i've heard all kinds of wacky explenation about what tachions are, honestl;y i thought Star trek made them up and then physisists named something they found later after them, but that may just be based in my own insanity.
Ok, there's no way to get a solar sail moving faster than the speed of light. Why? no matter how fast you run, light still moves at the speed of light in your frame. You can't chase a beam of light, it will never slow down when you speed up.
but large, thin sails that take advantage of radiation pressure are perfectly feasible, and have begun to be used by NASA.
In this sense, a solar sail COULD make use of solar winds, by harnessing the radiation/flow of particles. The only problem is that the pressure is going to drop off as 1/r^2 so you're not going to get going all that fast.
but large, thin sails that take advantage of radiation pressure are perfectly feasible, and have begun to be used by NASA.
In this sense, a solar sail COULD make use of solar winds, by harnessing the radiation/flow of particles. The only problem is that the pressure is going to drop off as 1/r^2 so you're not going to get going all that fast.
The big plus for sail-powerd vehicles is that they don't require fuel (or not as much), not that they go fast. Think about the ships in the seas on Earth today: a sail-boat is never going to run out of fuel, but a motor-boat is going win the race.
The way i thought solar sails could be used to travel faster than light is that they provide an extra boost to your engine to make you travel faster than light.you would have a reactor that puts you in a faster than light state then let your engines do the rest of the work.The solar sails are there simply to collect light, or the energy of light and turn it into a fuel for your stardrive.IF tachyons do exist then maybe the sails could be used to ride them but it wouldnt make much diferrance as there is allways some amount of light around you wether your traveling faster than it or not.
However, if tachyons were ther and you could connect to them by means of electrmagnets and sails to catch the light maybe you could ride them like the way a surfer rides the wave.
But back to the game I think this would be a cool feature to the game and how running and chasing works.
And even if this tachyon stuff is just hocus-pocus then you can still use normal for long range research craft or moving away from a star to conserve fuel.
But back to the game I think this would be a cool feature to the game and how running and chasing works.
And even if this tachyon stuff is just hocus-pocus then you can still use normal for long range research craft or moving away from a star to conserve fuel.
Nobody read the links I posted I guess.
"...A square mirror 1 kilometer on a side would only feel about 9 Newtons or 2 pounds of force. Fortunately, space is very empty and clean compared to Earth, so there is plenty of room for a 1 kilometer wide sail to maneuver, and there is no noticeable friction to interfere with your 9 Newtons of thrust."
There's not much thrust to be had, the sail is much more effective near the sun, and the effect is quite directional. It's fun to talk about, but the technology is much more suited to long-range probes that don't change course much and have lots of space and time to get up to speed.
"...A square mirror 1 kilometer on a side would only feel about 9 Newtons or 2 pounds of force. Fortunately, space is very empty and clean compared to Earth, so there is plenty of room for a 1 kilometer wide sail to maneuver, and there is no noticeable friction to interfere with your 9 Newtons of thrust."
There's not much thrust to be had, the sail is much more effective near the sun, and the effect is quite directional. It's fun to talk about, but the technology is much more suited to long-range probes that don't change course much and have lots of space and time to get up to speed.
FM,
solar sails could be used in a maner similar to their wind-based namesakes, if and only if there were a iechnology that could do the job of a centerboard (provide lateral resistance). now, in space there realy isn't anything for a "centerboard" to dig into. so some sort of magicla sceincy-fictionalgravity centeboard has to be used instead.
anyway, there was a point to this post but i forgot what it was....
solar sails could be used in a maner similar to their wind-based namesakes, if and only if there were a iechnology that could do the job of a centerboard (provide lateral resistance). now, in space there realy isn't anything for a "centerboard" to dig into. so some sort of magicla sceincy-fictionalgravity centeboard has to be used instead.
anyway, there was a point to this post but i forgot what it was....
I'll grant you the centerboard idea for the sake or argument. What about only 2 pounds of thrust from a 1 kilometer-wide sail? It's going to take awhile to get up to speed.
I'm not arguing against the feasability of solar sails in space, I'm arguing against the idea that such a thing would be practical in the VO universe on our current types of ships.
I'm not arguing against the feasability of solar sails in space, I'm arguing against the idea that such a thing would be practical in the VO universe on our current types of ships.
Indeed. Although it's a constantly applied force (acceleration = infinite), I don't see other uses for it besides long-term station redeployment... but you could do that with slingshots...
I guess it'd be useful for deep space probes where it doesn't matter when (if) they return.
I already forgot again what the consensus was in the last big propulsion discussion, but I think we still have non-newtonian engines in our ships. That effectively voids the right of existence of any new technology that relies on other things besides actio = reactio. I think it was Celebrim (who else, really?) who mentioned the problem of heat dissipation being far more important. I guess the ramscoop wouldn't be that bad an idea after all, at least not for long-range ships (you could gather particles, bestow energy (heat) upon them, and release them again).
That being said, I bet it'd look awesome to see a capital ship set her giant sails in space.
Oh, and one last thing: Physics majors are crazy people.
I guess it'd be useful for deep space probes where it doesn't matter when (if) they return.
I already forgot again what the consensus was in the last big propulsion discussion, but I think we still have non-newtonian engines in our ships. That effectively voids the right of existence of any new technology that relies on other things besides actio = reactio. I think it was Celebrim (who else, really?) who mentioned the problem of heat dissipation being far more important. I guess the ramscoop wouldn't be that bad an idea after all, at least not for long-range ships (you could gather particles, bestow energy (heat) upon them, and release them again).
That being said, I bet it'd look awesome to see a capital ship set her giant sails in space.
Oh, and one last thing: Physics majors are crazy people.
/me poofs back again.
Shape : The virtual particles, those you see in feynman diagrams, even those that travel "back in time" are not tachyons. They are simply time-reversed particles. Remember the charge-parity-time (CPT) symmetry allows you to describe some particles travelling forward in time as anti-charged particles travelling backward in time. This is another reason why physicist don't think of tachyons as FTL particles, tachyons are imaginary mass particles, period. Oh yeah, lots of unified theories are literally dripping with them. One of the things they teach you in bosonic string theory is how to calculate the crossection of a 4-vertex tachyon interaction. There is no accounting for taste in physics.
Solar Sails : FM+Shape is mostly right. They are directional, they can't make you go FTL. They are very weak, but FM's 9N/km^2 is a value you get for a sail at 1 AU from the Sun (1 AU = distance from sun to earth). You can get a bit more, sa for an O-class star, at 1 A.U., to maybe 1000N but not much more. Of course they drop of as 1/r^2 from the source of radiation. However, as some posters mention, you can shoot lasers at them. One idea of interstellar travel is to build a giant mirror to focus light from the sun on a solar sail.
Lebermac : You are talking about the Einstein-Podolsky-Rosen paradox, which has nothing to do with tacyhons or FTL particles. EPR is an attempt to show that quantum mechanics violate causality. They try to show this by saying that QM predicts 2 particles traveling at opposite directions to each other, must communicate their "spin" information instantaneously, so QM must be wrong. However this experiment, impossible during Einstein's days, has been done countless times at increasing distances (over several countries in europe, i forgot which), and the particles behave as they are predicted by QM. They do not violate causality in anyway, since you can't transfer information using this method (it's complicated to explain, sorry, but i can try if you are really curious. EDIT : The key word is that QM predicts a correlation, not causation.)
[EDIT : As i was getting coffee, I was told that the student labs here has bought a new experiment to demonstrate Bell's inequality, which is basically the experiment that verifies the "spooky action at a distance" of EPR. Well then, Albert must be rolling in his grave. I didn't know that you have a tabletop experiment for this seminal fact about QM!)
/me poofs.
Shape : The virtual particles, those you see in feynman diagrams, even those that travel "back in time" are not tachyons. They are simply time-reversed particles. Remember the charge-parity-time (CPT) symmetry allows you to describe some particles travelling forward in time as anti-charged particles travelling backward in time. This is another reason why physicist don't think of tachyons as FTL particles, tachyons are imaginary mass particles, period. Oh yeah, lots of unified theories are literally dripping with them. One of the things they teach you in bosonic string theory is how to calculate the crossection of a 4-vertex tachyon interaction. There is no accounting for taste in physics.
Solar Sails : FM+Shape is mostly right. They are directional, they can't make you go FTL. They are very weak, but FM's 9N/km^2 is a value you get for a sail at 1 AU from the Sun (1 AU = distance from sun to earth). You can get a bit more, sa for an O-class star, at 1 A.U., to maybe 1000N but not much more. Of course they drop of as 1/r^2 from the source of radiation. However, as some posters mention, you can shoot lasers at them. One idea of interstellar travel is to build a giant mirror to focus light from the sun on a solar sail.
Lebermac : You are talking about the Einstein-Podolsky-Rosen paradox, which has nothing to do with tacyhons or FTL particles. EPR is an attempt to show that quantum mechanics violate causality. They try to show this by saying that QM predicts 2 particles traveling at opposite directions to each other, must communicate their "spin" information instantaneously, so QM must be wrong. However this experiment, impossible during Einstein's days, has been done countless times at increasing distances (over several countries in europe, i forgot which), and the particles behave as they are predicted by QM. They do not violate causality in anyway, since you can't transfer information using this method (it's complicated to explain, sorry, but i can try if you are really curious. EDIT : The key word is that QM predicts a correlation, not causation.)
[EDIT : As i was getting coffee, I was told that the student labs here has bought a new experiment to demonstrate Bell's inequality, which is basically the experiment that verifies the "spooky action at a distance" of EPR. Well then, Albert must be rolling in his grave. I didn't know that you have a tabletop experiment for this seminal fact about QM!)
/me poofs.
/me wants Holden back ingame...
Get those students working on the gravitic drives!
Off topic sorry:
And I'd actually LIKE to hear why, for example, you couldn't set up a way to transfer information by using two widely separated "twin" particles.
Example:
In the future, scientists set up a space-lab that studies solar flares in orbit around the sun. In order to warn of a massive flare, the scientists would have to use an FTL means of communication in order to "Beat" the high-energy particles back to Earth, giving us a whole 8 minutes to shield our satellites and our computers and our power grids, etc.
So they set up a way to change the spin of a quantum particle, and then they create a set of particles, leave one on earth and take the other one to the solar space-lab. By alternating the spin of one particle on the space-lab, they could communicate instantly by using a digital code, since the particle left on earth would be alternating spin as well at the same time. (Can you determine/measure spin without affecting the particle?)
I'm sure that's more science fiction than science fact, but the explanation of WHY it fails would interest me.
Get those students working on the gravitic drives!
Off topic sorry:
And I'd actually LIKE to hear why, for example, you couldn't set up a way to transfer information by using two widely separated "twin" particles.
Example:
In the future, scientists set up a space-lab that studies solar flares in orbit around the sun. In order to warn of a massive flare, the scientists would have to use an FTL means of communication in order to "Beat" the high-energy particles back to Earth, giving us a whole 8 minutes to shield our satellites and our computers and our power grids, etc.
So they set up a way to change the spin of a quantum particle, and then they create a set of particles, leave one on earth and take the other one to the solar space-lab. By alternating the spin of one particle on the space-lab, they could communicate instantly by using a digital code, since the particle left on earth would be alternating spin as well at the same time. (Can you determine/measure spin without affecting the particle?)
I'm sure that's more science fiction than science fact, but the explanation of WHY it fails would interest me.
This is offtopic. But Lebermac asked for it, so blame him.
The short answer is that you can't transfer information in your setup, because you can't choose what "spin" you want to measure.
When you set up your system, the people in the space lab and on earth will have a set of "entangled" states. however, as soon as one of the parties makes a measurements, it is a measurement on the whole system not just their respective systems. The spin states are correlated, but not causally connected. "Cause" means doing "A" results in "B". Here you have no choice in choosing to do "A" : you simply make measurements and see what your particle state is, and your friend lightyears away will make her own measurements. When you both eventually get together and compare notes, you will find that your measurements are correlated. Notice that neither of you have transfered information, what you have is that both of your results are correlated in a way predicted by QM.
The paradox arises only when you try to think that the 'particles' somehow communicated their measured value to its counterpart lightyears away, thus violating the speed of light limit. It's not "wrong" per se, but it is not useful to think this way.
Is it unintuitive? Maybe. The funny thing is, I find it perfectly reasonable but then this is my bread and butter. I'll find any violations of such QM correlations "spooky".
The short answer is that you can't transfer information in your setup, because you can't choose what "spin" you want to measure.
When you set up your system, the people in the space lab and on earth will have a set of "entangled" states. however, as soon as one of the parties makes a measurements, it is a measurement on the whole system not just their respective systems. The spin states are correlated, but not causally connected. "Cause" means doing "A" results in "B". Here you have no choice in choosing to do "A" : you simply make measurements and see what your particle state is, and your friend lightyears away will make her own measurements. When you both eventually get together and compare notes, you will find that your measurements are correlated. Notice that neither of you have transfered information, what you have is that both of your results are correlated in a way predicted by QM.
The paradox arises only when you try to think that the 'particles' somehow communicated their measured value to its counterpart lightyears away, thus violating the speed of light limit. It's not "wrong" per se, but it is not useful to think this way.
Is it unintuitive? Maybe. The funny thing is, I find it perfectly reasonable but then this is my bread and butter. I'll find any violations of such QM correlations "spooky".
Hehe. Thank you Holden.
Class dismissed. :)
Class dismissed. :)