We should see the mirror effect of lightsources that "were coming from some point at some time, and which appear from the oposite direction in the exact same (inversed) way at a precise later time. Those Timings and directions being influenced by our observer's relative position to an original source and "where was 'its' equator" ('its' because we all have one) then and now.
I think there is active research into this, ie, we should be able to see an image of our own galaxy out there somewhere, and it is being looked for. There was an article about it in a New Scientist/Scientific American/??? a few years ago, sorry that's all info I have.:)
Re:Wouldn't the Galaxies just pass through each ot
on
When Galaxies Collide
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· Score: 1
Just for interest sake, if you scale the time dimension to the same ratio as the space dimension (stars are ~10^19 bigger than a molecule), a molucule would collide with another (at STP) every ~100 years instead of 2E-10s.
Which is of course a lot more frequent than the observed rate of stellar collisions. The two situations are qualitatively very different of course, given that one is largely governed by long-distance gravitational attraction and the other by short-range electric repulsion, and so the comparison is really not a well advised one.
Re:Wouldn't the Galaxies just pass through each ot
on
When Galaxies Collide
·
· Score: 1
Compare the planetary bodies to the molecules and atoms in the air. Compared to their size, they are pretty far apart, and yet affect one another when huge clusters collide. That's how I understand it.
But the molecules in air collide quite regularly, and just bounce off each other, to a first approximation. When far apart their influence on each other is minimal. The bodies in a galaxy on the other hand influence one another at a distance due to gravity, don't bounce around between one another, and two stars colliding would probably be quite unlike two billiard balls colliding;)
He came back and blew my mind by stating "I voted for Clinton, because he is going to win anyway" (this is what I call the football game mentality of polls... he wanted to be a "WINNER")
I fear that this sort of thing is pretty prevalent. It's probably the simplest way to ensure that the candidate you vote for wins (and then feel good about it), and for a lot of 'swing voters', that's probably more important (subconciously at least) than the candidate's policies (given the slightness of the differentiation between the policies of the 2 main candidates anyway).
I don't think it would be much different from playing an FPS on a real big monitor with your face up close.The only reason that might make you sick as hell is the bloody giblets all over the floor.
It should be noted however that FPSs on standard monitors DO make some people sick (due to the motion, not the content). Perhaps more people would suffer from this with HMDs?
You might start by reading Declaration of War over at wikipedia. It's far more informed than your little diatribe.
Editors: this is not news, this is nonsense!
Granted, far more interesting news on the warmongering front can be found here, and I quote:
"...the Prime Minister faced yet more unwelcome news over the weekend. Confidential Foreign Office documents were leaked to a London-based newspaper confirming once and for all that Mr Blair invaded Iraq, not, as he has repeatedly claimed, because he believed Saddam Hussein had WMDs, but because both he and George Bush wanted regime change. The papers also confirm that Mr Blair knew invasion for regime change was illegal under international law, and that he realised the only way of getting a sceptical British public and Parliament to back Bush's war was by mounting a case that Saddam was a threat to the world."
However, a nice, crisp 3D display with mouse-driven movement of the scene should be a perfectly acceptable low-cost alternative.
If your entire field of view is filled by the display, and moving your head has no effect on what you see, but moving your mouse does, wouldn't that make you sick as hell?
It's gonna make things a whole lot more obvious when Doom V requires a level 13 system to run at full detail, and at at the time of release the best PC available for purchase is a level 11.;)
Second, my camera can withstand looking at the sun for a period of time (not much time, I'm sure).
The diffuse thing aside, I guess it all depends how short the pulse is. Make the pulse short enough, and the heat can't conduct away from target fast enough, and it will trash it.
That is to say, an N watt continous laser may be relatively harmless, but a laser with the same time averaged power concentrated into short pulses (eg one millisecond pulse every second) could cut steel.
Incidentally, if this laser is situated besides a nuclear power plant, there is probably plenty of juice available to power the damn thing, so it could potentially be a big MFer.
But the DNA by itself isn't so useful. To stretch an analogy, it's like getting the source code with any of the hardware - there's no telling what it's supposed to do if you've never seen the architecture or the language it's supposed to run on.
I disagree. The interactions of genetic molecules are governed at the lowest level by the laws of physics. Consider a civilization with a far greater understanding of physical chemistry, and computers far more powerful than we have. I think it's plausible that they could simulate the interactions that would take place in a living entity well enough to get a good picture of its physiology.
Of course CGTAGTAGTAAT.... isn't going to be too useful to them, unless we include the molecular structure of the bases, OR it turns out that the way genetics is done on earth is the unique (or near enough to ) solution to the how_to_build_life problem within the constraints of our universe. (If they know that our physiology must be one out of 1000 possible or so, then we are still potentially screwed.)
Voyager scientists attach a plaque on the outbound trip - aliens attach a plague on the return trip.
Humour (and possibly rationality) aside, doesn't the idea of sending a copy of our global genome into space sound a little risky?
Aliens may well be friendly, but if not, do we really want them to have a greater understanding of our physiology than we do? (We have the whole genome but can't make heads or tails of most of it, presumably with more advanced technology they could infer a lot more about us from the genome than we can presently.)
I am going to have to disagree here. I believe its more along the lines of behaving like the jerks they are inside instead of the nice geeks they are outside. I think peoples attitudes on the internet are the way they really are, and they restrain theirselves in the real world.
Nobody's suggesting using coal as a nuclear fuel. Just pointing out how radioactive it is.
Why then, was he comparing the energy yielded by combustion to that which could be obtained by fission? Seems that he was talking about its potential as a nuclear fuel to me, the radiation it emits wasn't mentioned at all.
Hey, It happens to be that when something moves it wants to conserve momentum, thus go in a straight line. When something goes around a curve, it must have a force acting on it, thus it undergo acceleration.
Yes, and when you accelerate a charged particle, it sheds energy in the form of EM radiation. This is what the parent said.
This is why the pre-quantum model of the atom was absurd: Orbiting electron bleeds energy due to centripetal acceleration, the orbit decays, and the electron crashes into the nucleus in ~ 10^-16 s.
Their legacy extends to their hyperlinking policy, which says that you have to apply in writing - they even include a snail-mail address - before linking to the Athens Olympic site[athens2004.com].
Dear Sir,
Upon reading your comment we have found that you are in full awareness of the hyperlinking policy that you have just violated. See you in court, and be sure to bring bags and bags of money.
I, like most I assume, have never really gotten a firm grasp of the reality of time dilation. Basically, here's my own practical implementation: The faster you go, the longer it seems that you take to people that aren't going with you (stayed on Earth).
Someone has posted a nice answer to your question already, although I feel I might be able to clarify this bit for you.
As the sister post to this states, if you travel 10 ly away from earth and back, it will take you 20 yrs minimum, as observed from earth. It's more informative to consider what's observed in the spaceship.
If the spaceship was travelling at the speed of light, then the time dilation is infinite. What this means, is that time has stopped on the spaceship. However much time passes on earth, and NO time passes on the spaceship. Also, length contraction is infinite. What this means, is that a distance as measured from earth's point of view, say the 3000 lys (?) to Andromeda, is measured to be ZERO distance by the spaceship. Both are complimentary views of the same effect: at light-speed, the ship sees itself as travelling at infinite speed across the universe, while the earth sees it as travelling at the speed of light.
This is the extreme relativistic limit, and it's easy to see that at 0.99c or whatever, very little time passes on the ship, and the distance becomes very small, but both remain finite.
I'm sure most of us have looked up at the night sky and thought 'wow, that light I'm seeing left that star however many million years ago, and I'm looking into past, etc'. Consider the photons in light (pun not intended) of what was discussed above: the photons have travelled say, 1 million lys, in 1 million yrs, from your point of view. However, the photons live in the extreme relativistic limit, hence they have experienced no time passage at all, they appear at your retina instantly. Hence, if photons were unstable, and decayed with some half-life, we'd never know, because all photons exist for an infinitesimally short span of time. Understand that, and space-time diagrams, delineated by the paths of light rays, begin to make some sense (the operative word being 'some').
All this is explained in terms of Special Relativity, which deals only with motion at a constant velocity (ie in an 'inertial frame'). Acceleration is covered by General Relativity. Any 'return trip' away from earth is going to involve a change in direction (an acceleration), which can be approximated under SR by a constant velocity away, and then a constant velocity back.
If you really want to damage your brain, consider that if the spaceship is receding from earth at light-speed, then from it's point of view earth is receding from it at light speed, and that therefore the same arguments made for the spaceship could be made for the earth, (ie that earth experiences no passage of time while the spaceship does), right?
The paradox is broken by including the effect of the turn around. As the spaceship must change direction, it no longer exists in only one inertial frame (ie one with no acceleration). The spaceship is what changes direction, the earth doesn't, hence the earth, being in only one inertial frame, is what will age compared to the ship, not vice versa. (Of course you could argue that from the ship's point of view, the earth changes direction, but the acceleration is really at the ship's end, as it experiences the applied force, ie effect of the retro-rockets, or the solar-sail, which is a real acceleration, not a 'relative' one).
I don't follow. Just accelerate at 1g for 5 times as long (around a year) and everyone's comfortable. Accelerating the other direction at Alpha Centauri would be another year and you're still well under a decade for a one-way trip.
The problem (aside from energy considerations...) is time dilation. That 1 year is 1 year in the spaceship. It's a whole lot more in the frame of say, earth. I *think* it works out that it takes infinite time in the frame that was coincident with the spaceship's frame before it began accelerating.
Actually I'm pretty sure thats right; consider the spaceship at 0.9c, after 319 days of acceleration. On that day, the ship adds another day's worth acceleration to it's speed, however time dilation is now more than 2x, so that change in speed occurs over (more than) 2 days, as observed in the other frame. As the ship's speed approaches that of light, time dilation approaches infinity, and as such the acceleration as observed in the other frame approaches zero.
The moral of the story being, you can accelerate a massive object to the speed of light (neglecting energy considerations, which aren't something you can really neglect in this case:) ), however the universe will end before it gets there.
Slashdot Mirror
We should see the mirror effect of lightsources that "were coming from some point at some time, and which appear from the oposite direction in the exact same (inversed) way at a precise later time. Those Timings and directions being influenced by our observer's relative position to an original source and "where was 'its' equator" ('its' because we all have one) then and now.
:)
I think there is active research into this, ie, we should be able to see an image of our own galaxy out there somewhere, and it is being looked for. There was an article about it in a New Scientist/Scientific American/??? a few years ago, sorry that's all info I have.
Just for interest sake, if you scale the time dimension to the same ratio as the space dimension (stars are ~10^19 bigger than a molecule), a molucule would collide with another (at STP) every ~100 years instead of 2E-10s.
Which is of course a lot more frequent than the observed rate of stellar collisions. The two situations are qualitatively very different of course, given that one is largely governed by long-distance gravitational attraction and the other by short-range electric repulsion, and so the comparison is really not a well advised one.
Compare the planetary bodies to the molecules and atoms in the air. Compared to their size, they are pretty far apart, and yet affect one another when huge clusters collide. That's how I understand it.
;)
But the molecules in air collide quite regularly, and just bounce off each other, to a first approximation. When far apart their influence on each other is minimal. The bodies in a galaxy on the other hand influence one another at a distance due to gravity, don't bounce around between one another, and two stars colliding would probably be quite unlike two billiard balls colliding
"All of a sudden, causality decided to give physical laws and time the finger,
Actually physical laws appear to have given causality the finger quite a while ago.
He came back and blew my mind by stating "I voted for Clinton, because he is going to win anyway" (this is what I call the football game mentality of polls ... he wanted to be a "WINNER")
I fear that this sort of thing is pretty prevalent. It's probably the simplest way to ensure that the candidate you vote for wins (and then feel good about it), and for a lot of 'swing voters', that's probably more important (subconciously at least) than the candidate's policies (given the slightness of the differentiation between the policies of the 2 main candidates anyway).
Computer virusen are actually like STD's.
Virusen? That's just terrible.
Yes we are. And you're going to like it. We welcome our new Google masters...
Overlords. Our new Google Overlords. Obviously there is someone that hasn't heard it enough already. Who woulda thunk it?
I don't think it would be much different from playing an FPS on a real big monitor with your face up close.The only reason that might make you sick as hell is the bloody giblets all over the floor.
It should be noted however that FPSs on standard monitors DO make some people sick (due to the motion, not the content). Perhaps more people would suffer from this with HMDs?
You might start by reading Declaration of War over at wikipedia. It's far more informed than your little diatribe. Editors: this is not news, this is nonsense!
Granted, far more interesting news on the warmongering front can be found here, and I quote:
"...the Prime Minister faced yet more unwelcome news over the weekend. Confidential Foreign Office documents were leaked to a London-based newspaper confirming once and for all that Mr Blair invaded Iraq, not, as he has repeatedly claimed, because he believed Saddam Hussein had WMDs, but because both he and George Bush wanted regime change. The papers also confirm that Mr Blair knew invasion for regime change was illegal under international law, and that he realised the only way of getting a sceptical British public and Parliament to back Bush's war was by mounting a case that Saddam was a threat to the world."
However, a nice, crisp 3D display with mouse-driven movement of the scene should be a perfectly acceptable low-cost alternative.
If your entire field of view is filled by the display, and moving your head has no effect on what you see, but moving your mouse does, wouldn't that make you sick as hell?
It's gonna make things a whole lot more obvious when Doom V requires a level 13 system to run at full detail, and at at the time of release the best PC available for purchase is a level 11. ;)
Second, my camera can withstand looking at the sun for a period of time (not much time, I'm sure).
The diffuse thing aside, I guess it all depends how short the pulse is. Make the pulse short enough, and the heat can't conduct away from target fast enough, and it will trash it.
That is to say, an N watt continous laser may be relatively harmless, but a laser with the same time averaged power concentrated into short pulses (eg one millisecond pulse every second) could cut steel.
Incidentally, if this laser is situated besides a nuclear power plant, there is probably plenty of juice available to power the damn thing, so it could potentially be a big MFer.
There is nothing wrong with using the word speed, especially when vonerting everything to time.
Agreed, in this context it is a perfectly cromulent word.
There's a mistake in the HTML, which caused the story to lose some of its meaning:
...informing me that two of the greatest made for TV movies of all time will be coming out on...
...informing me that <sarcasm> two of the greatest made for TV movies of all time </sarcasm> will be coming out on...
should have read:
Plus 0/0 is undefined, so you can't really say anything about N.
Maybe if you took the limit and applied l'Hopital's rule.
Nah, that's just sad. Sorry.
But the DNA by itself isn't so useful. To stretch an analogy, it's like getting the source code with any of the hardware - there's no telling what it's supposed to do if you've never seen the architecture or the language it's supposed to run on.
I disagree. The interactions of genetic molecules are governed at the lowest level by the laws of physics. Consider a civilization with a far greater understanding of physical chemistry, and computers far more powerful than we have. I think it's plausible that they could simulate the interactions that would take place in a living entity well enough to get a good picture of its physiology.
Of course CGTAGTAGTAAT.... isn't going to be too useful to them, unless we include the molecular structure of the bases, OR it turns out that the way genetics is done on earth is the unique (or near enough to ) solution to the how_to_build_life problem within the constraints of our universe. (If they know that our physiology must be one out of 1000 possible or so, then we are still potentially screwed.)
Voyager scientists attach a plaque on the outbound trip - aliens attach a plague on the return trip.
Humour (and possibly rationality) aside, doesn't the idea of sending a copy of our global genome into space sound a little risky?
Aliens may well be friendly, but if not, do we really want them to have a greater understanding of our physiology than we do? (We have the whole genome but can't make heads or tails of most of it, presumably with more advanced technology they could infer a lot more about us from the genome than we can presently.)
I believe it wasn't just in the middle east -- as I recall, that's where the word 'salary' comes from.
And the expression "worth his/her/its salt."
Oh give me a clone,
of my own flesh and bone,
with its Y chromosome changed to X
I am going to have to disagree here. I believe its more along the lines of behaving like the jerks they are inside instead of the nice geeks they are outside. I think peoples attitudes on the internet are the way they really are, and they restrain theirselves in the real world.
Isn't this just the old Hobbes vs. Rousseau debate?
Nobody's suggesting using coal as a nuclear fuel. Just pointing out how radioactive it is.
Why then, was he comparing the energy yielded by combustion to that which could be obtained by fission? Seems that he was talking about its potential as a nuclear fuel to me, the radiation it emits wasn't mentioned at all.
Hey, It happens to be that when something moves it wants to conserve momentum, thus go in a straight line. When something goes around a curve, it must have a force acting on it, thus it undergo acceleration.
Yes, and when you accelerate a charged particle, it sheds energy in the form of EM radiation. This is what the parent said.
This is why the pre-quantum model of the atom was absurd:
Orbiting electron bleeds energy due to centripetal acceleration, the orbit decays, and the electron crashes into the nucleus in ~ 10^-16 s.
Their legacy extends to their hyperlinking policy, which says that you have to apply in writing - they even include a snail-mail address - before linking to the Athens Olympic site[athens2004.com].
Dear Sir,
Upon reading your comment we have found that you are in full awareness of the hyperlinking policy that you have just violated. See you in court, and be sure to bring bags and bags of money.
Sincerely,
The IOC.
I, like most I assume, have never really gotten a firm grasp of the reality of time dilation. Basically, here's my own practical implementation: The faster you go, the longer it seems that you take to people that aren't going with you (stayed on Earth).
Someone has posted a nice answer to your question already, although I feel I might be able to clarify this bit for you.
As the sister post to this states, if you travel 10 ly away from earth and back, it will take you 20 yrs minimum, as observed from earth. It's more informative to consider what's observed in the spaceship.
If the spaceship was travelling at the speed of light, then the time dilation is infinite. What this means, is that time has stopped on the spaceship. However much time passes on earth, and NO time passes on the spaceship. Also, length contraction is infinite. What this means, is that a distance as measured from earth's point of view, say the 3000 lys (?) to Andromeda, is measured to be ZERO distance by the spaceship. Both are complimentary views of the same effect: at light-speed, the ship sees itself as travelling at infinite speed across the universe, while the earth sees it as travelling at the speed of light.
This is the extreme relativistic limit, and it's easy to see that at 0.99c or whatever, very little time passes on the ship, and the distance becomes very small, but both remain finite.
I'm sure most of us have looked up at the night sky and thought 'wow, that light I'm seeing left that star however many million years ago, and I'm looking into past, etc'. Consider the photons in light (pun not intended) of what was discussed above: the photons have travelled say, 1 million lys, in 1 million yrs, from your point of view. However, the photons live in the extreme relativistic limit, hence they have experienced no time passage at all, they appear at your retina instantly. Hence, if photons were unstable, and decayed with some half-life, we'd never know, because all photons exist for an infinitesimally short span of time. Understand that, and space-time diagrams, delineated by the paths of light rays, begin to make some sense (the operative word being 'some').
All this is explained in terms of Special Relativity, which deals only with motion at a constant velocity (ie in an 'inertial frame'). Acceleration is covered by General Relativity. Any 'return trip' away from earth is going to involve a change in direction (an acceleration), which can be approximated under SR by a constant velocity away, and then a constant velocity back.
If you really want to damage your brain, consider that if the spaceship is receding from earth at light-speed, then from it's point of view earth is receding from it at light speed, and that therefore the same arguments made for the spaceship could be made for the earth, (ie that earth experiences no passage of time while the spaceship does), right?
The paradox is broken by including the effect of the turn around. As the spaceship must change direction, it no longer exists in only one inertial frame (ie one with no acceleration). The spaceship is what changes direction, the earth doesn't, hence the earth, being in only one inertial frame, is what will age compared to the ship, not vice versa. (Of course you could argue that from the ship's point of view, the earth changes direction, but the acceleration is really at the ship's end, as it experiences the applied force, ie effect of the retro-rockets, or the solar-sail, which is a real acceleration, not a 'relative' one).
I don't follow. Just accelerate at 1g for 5 times as long (around a year) and everyone's comfortable. Accelerating the other direction at Alpha Centauri would be another year and you're still well under a decade for a one-way trip.
:) ), however the universe will end before it gets there.
The problem (aside from energy considerations...) is time dilation. That 1 year is 1 year in the spaceship. It's a whole lot more in the frame of say, earth. I *think* it works out that it takes infinite time in the frame that was coincident with the spaceship's frame before it began accelerating.
Actually I'm pretty sure thats right; consider the spaceship at 0.9c, after 319 days of acceleration. On that day, the ship adds another day's worth acceleration to it's speed, however time dilation is now more than 2x, so that change in speed occurs over (more than) 2 days, as observed in the other frame. As the ship's speed approaches that of light, time dilation approaches infinity, and as such the acceleration as observed in the other frame approaches zero.
The moral of the story being, you can accelerate a massive object to the speed of light (neglecting energy considerations, which aren't something you can really neglect in this case