*duct tapes a coin slot to Omnutia's chest* 25 pence/reference!
You moose, the duct tape is covering the slot. I appreciate the thought though. I should have used the word example instead of reference. For those of you who have played it RA and RA2 extend world war 2 which, while some would argue was better than genocide, may not have been. The moral: While the past was shit, it could have been much worse.
*duct tapes a coin slot to Omnutia's chest* 25 pence/reference!
You moose, the duct tape is covering the slot. I appreciate the thought though. I should have used the word example instead of reference. For those of you who have played it RA and RA2 extend world war 2 which, while some would argue was better than genocide, may not have been. The moral: While the past was shit, it could have been much worse.
I sometimes wonder how messed up the world could get if mankind was really trying or just stopped trying against falling into ruin.
Just look at the Cold War. Literally, the only thing which was stopping total destruction was the knowledge that if either the USSR or the United States initiated a nuclear strike, before the impact happened, the other power would launch enough nukes to destroy all of mankind. There were many occasions where the situation was a hair's breadth away from getting to that point, too.
One thing I have never understood about time travel and the speed of light is why time "slows down" as you approach the speed of light.
Is time slowing down or are you slowing down? Is it just your perception of time that is slowing down?
I have never been able to accept the idea that time slows down as you approach the speed of light. I can accept that your perception of time slows down but not that time itself slows down. If time slowed down than once you reached the speed of light you would stop moving. As long as the vessel you are in continues to move at speed time is not slowing down or stopping.
If you had a powerful enough telescope you could (theoretically) travel faster than the speed of light and look behind you at the Earth and see what appears to be time in reverse. Time is not in reverse it is just that the light you are seeing is not travelling as fast as you are and you are seeing what happened in the past. This is no different than looking through a telescope on Earth at distant galaxies. We are not seeing them as they are today but as they were many years ago (depends on how many light years away they are.)
I have no doubt that the speed of light will eventually be surpassed through technology.
As to killing Hitler... I remember an issue of G.I. Combat (or some other 70's war comic) where they sent a lone gunman back in time to kill Hitler. I don't remember if he killed him or not but, the Nazis took the assassins gear, copied it and used it to win the war. I think there was some cheesy Sci-Fi movie (Philadelphia Experiment 2?) where an American Stealth Bomber ended up being transported back to Hitler's Germany with a few modern nukes on board. Germany dropped them on NYC and DC and that was the end of World War 2.
Is time slowing down or are you slowing down? Is it just your perception of time that is slowing down?
Your time as perceived by a "stationary" observer slows down. I say stationary in quotes because you can pick any frame of reference you want. If you're on a spaceship going at the speed of light (relative to say, the Earth), everything seems normal to you, but gosh, people on Earth sure are moving slow. Likewise, on Earth, people would see your ship cruise by at c, but you would look frozen in time on the ship. Again, no matter how fast you are moving, a second looks like a second to you, and light travels at 3*10^8 m/s.
I have no doubt that the speed of light will eventually be surpassed through technology.
If by this you mean we will make a spaceship that files faster than the speed of light, then it's not gonna happen. Given our current understanding of physics, any object with mass cannot exceed or even attain the speed of light. As any object approaches c, it becomes infinitely heavy, thereby requiring infinite energy to accelerate it to c. Now, this is not to say sometime in the future we might be able to devise a way to manipulate space such that we could take a "shortcut" and end up at some place before the light of our departure got there, but it would require something like extradimensional travel.
Now, this is not to say sometime in the future we might be able to devise a way to manipulate space such that we could take a "shortcut" and end up at some place before the light of our departure got there, but it would require something like extradimensional travel.
I think Carl Sagan had a theory that if we find some way to compress the space in front of us, and expand the space behind us, we could go faster than light. I think he used it in Contact.
Just look at the Cold War. Literally, the only thing which was stopping total destruction was the knowledge that if either the USSR or the United States initiated a nuclear strike, before the impact happened, the other power would launch enough nukes to destroy all of mankind. There were many occasions where the situation was a hair's breadth away from getting to that point, too.
I was thinking along the lines of what the world could become if we tried to ruin it over a long period. In a nuclear war, everyones dead but the suffering is relatively short term.
I have no doubt that the speed of light will eventually be surpassed through technology.
Sorry, but that's ridiculous. The speed of light is not a technological barrier, like the speed of sound. Many different physical things happen at near-c velocities. One notable thing that happens is that, since mass increases as velocity increases, the mass of a body propagating at c would be infinite. No level of technology is going to move that mass.
I think Carl Sagan had a theory that if we find some way to compress the space in front of us, and expand the space behind us, we could go faster than light. I think he used it in Contact.
I think what Neito was talking about was something similar to the Alcubierre Drive. The idea is that you would create a bubble around your ship in which retains normal relativistic properties. Outside this bubble however one would contract the space in front of you and expand the space behind you, creating a "cosmic wave" of sorts in which the bubble you are traveling in is pushed by this bending of space and time. It's faster than light in the sense that you can travel distances faster than light outside of the bubble however you cannot surpass the speed of light within your bubble. Because of this mechanic, the effects of relativity would not affect you in the sense that it would if you were to approach the speed of light in normal space.
However, the drawback of such a design would be the insanely large requirements for energy.
Here is an image of how such a bending of space would look like:
If information could travel faster than c in one reference frame, causality would be violated: in some other reference frames, the information would be received before it had been sent, so the "effect" could be observed before the "cause". Such a violation of causality has never been recorded[6].
I think the whole idea of time travel by passing the speed of light is based on the misunderstanding of causality in regards to c.
The information would not be received before it was sent. Breaking c does not result in time travel. The information may "appear" to have been received before it was sent only because the receiver would receive the information before they would be able to see (or observe) the sender send it (providing they had a good enough optics system to see the sender perform the task from a distance of several light seconds or more).
Let me put forth this hypothetical:
What if you had a wire that was one light year in length. It is made out of an indestructible substance that neither contracts nor expands. This wire is inside a hollow tube of the same material and both ends of the tubes open into rooms that are one light year apart. (I know this is impossible because there would be no way to keep these two rooms stationary and connected over such a vast distance but humor me.)
If you were to pull this wire in room A the person in room B would observe the wire moving at the same time even though the "I'm pulling the wire" message (traveling my radio wave at the speed of light) would not reach the other room for 1 year.
The wire is not moving at the speed of light, it is simply such a long wire (with special properties) that it can be used to transfer information faster than the speed of light.
Yes, this is 101% total science fiction and no such substance exists with the tensile strength to work in this way. The weight of the wire would prevent it from being pulled or it would require so much energy to move the wire that it would not be practical.
I can believe that science will allow us to travel faster than the speed of light but I can't believe in time travel (except into the future, which we do every day).
I've always been a fan of Tesseracts, as in A Wrinkle in Time. If you want to go from point A to point B, just bend reality such that point A is next to point B, then your destination is one step away. Don't go to places. Bring places to you.
Imagine a piece of paper. You want to get from one end of the paper to the other. Instead of walking across the entire paper, just fold the paper in half, jump to the other side, then unfold it.
Just get a portal gun and make your first portal. Then send that portal gun on a ship to a far away planet and create the second portal. Then get ready for the massive forces that are unleashed as both planets try to equalize their pressure now that they are connected.
If you were to pull this wire in room A the person in room B would observe the wire moving at the same time even though the "I'm pulling the wire" message (traveling my radio wave at the speed of light) would not reach the other room for 1 year.
I'm pretty sure that this wouldn't happen. If you were to pull this wire, the reactions of such a pull on the atoms of the wire would not occur faster than the speed of light. So if you were to pull such a wire, it would take significantly longer than a year for the guy on the other end to experience such a pull. Further explanation would require delving into the world of electromangetism though...
I think the whole idea of time travel by passing the speed of light is based on the misunderstanding of causality in regards to c.
No. The time dilation effect is real. The effect is mathematically described by the Lorentz Transformations. Look at the Lorentz Factor. Notice what is in the denominator. What happens when you increase v in that expression? Right. The denominator tends towards zero. What happens when you try to divide zero into one? That's why we see the time dilation effect. It doesn't come from hyptheticals or language. It comes from the math.
Let me put forth this hypothetical:
What if you had a wire that was one light year in length. It is made out of an indestructible substance that neither contracts nor expands. This wire is inside a hollow tube of the same material and both ends of the tubes open into rooms that are one light year apart. (I know this is impossible because there would be no way to keep these two rooms stationary and connected over such a vast distance but humor me.)
If you were to pull this wire in room A the person in room B would observe the wire moving at the same time even though the "I'm pulling the wire" message (traveling my radio wave at the speed of light) would not reach the other room for 1 year.
The wire is not moving at the speed of light, it is simply such a long wire (with special properties) that it can be used to transfer information faster than the speed of light.
Yes, this is 101% total science fiction and no such substance exists with the tensile strength to work in this way. The weight of the wire would prevent it from being pulled or it would require so much energy to move the wire that it would not be practical.
There's a point at which hypotheticals don't give you a good picture of the physical world because they're too disconnected from the physical world. You've imagined multiple impossibilities to explain how another impossibility can be possible. That hypothetical is useless in actually explaining anything. It's like if I said, "Imagine Glenda the Good Witch is standing one light year away from me. She sends me a magic message at the same time she sends me a radio message. I receive the magic message first, and so Glenda has sent information at faster than light speed."
I can believe that science will allow us to travel faster than the speed of light but I can't believe in time travel (except into the future, which we do every day).
Do you believe you can divide zero into one? Because that's what kind of mass you'd have to push at relativistic velocities. You love to quibble and shit-talk, so I'd love to hear your answer to that. Divide zero into one and tell me the result.
I'm pretty sure that this wouldn't happen. If you were to pull this wire, the reactions of such a pull on the atoms of the wire would not occur faster than the speed of light. So if you were to pull such a wire, it would take significantly longer than a year for the guy on the other end to experience such a pull. Further explanation would require delving into the world of electromangetism though...
The hypothetical wire would not be subject to this. It does not stretch or compress.
Gravitational time dilation has been experimentally measured using atomic clocks on airplanes. The clocks that traveled aboard the airplanes upon return were slightly fast with respect to clocks on the ground. The effect is significant enough that the Global Positioning System needs to correct for its effect on clocks aboard artificial satellites, providing a further experimental confirmation of the effect.
Yes, the clock on the plane was slightly faster but was time moving at a different speed or is it a case of gravity having an effect on the way the clock works? Does an atomic clock track time itself or something that can be influenced by gravitational forces?
Yes, the clock on the plane was slightly faster but was time moving at a different speed or is it a case of gravity having an effect on the way the clock works? Does anatomic clocktrack time itself or something that can be influenced by gravitational forces?
It's the math again. All you have to do is look at the math. It's not gravity working on the clock. It's gravity causing a time dilation effect.
Time Dilation is not Time Travel.
You said:
I think the whole idea of time travel by passing the speed of light is based on the misunderstanding of causality in regards to c.
It's not. It comes from actually looking at the equation and imagining what would happen if v were to increase to the point that it was greater than c. What happens if you substitute 2c into that Lorentz Factor? Right. You get an imaginary expression. That would seem to mean that something is happening to time that is not normal, wouldn't it? What would be not normal? Time running backwards. It's not someone's "misunderstanding" because they came up with a silly hypothetical. It's the math.
Just because the process an atomic clock uses for its timing operates differently based on gravity does not mean that time itself is moving at a different speed. A better experiment would be to take multiple timing devices along for the trip and see if they are all off by the same amount of time when they return.
Math has been wrong before and some math works only until you hit a certain point and then it breaks down. I simply can not accept that passing the speed of light involves time travel.
It has been proven that light travels at slower speeds through some mediums. Diamond in particular slows down light to a very high degree. Even fiber optic cables slow down light to some degree. Is it not possible that a medium may exist in which light moves faster? Might the severe gravitational forces of a black hole cause light to move faster than c as it pulls it in? If that light is pulled in faster than c is that light now moving backward in time?
Just because the process an atomic clock uses for its timing operates differently based on gravity does not mean that time itself is moving at a different speed. A better experiment would be to take multiple timing devices along for the trip and see if they are all off by the same amount of time when they return.
It's not the clock, Steve. Gravity affects time itself. That's what the equations say. It doesn't have anything to do with what sort of clock you carry.
Math has been wrong before and some math works only until you hit a certain point and then it breaks down.
When has it been wrong? Are you suggesting that Relativity is wrong? That's really what you're suggesting because the math is Relativity. The hypotheticals don't mean anything compared to the math. Tell me what point you're talking about at which math breaks down and how that might affect Relativity.
Weren't you the one who thought you needed calculus to solve a quadratic equation? I don't think you have any basis to be criticizing the mathematics of Relativity. Yeah, that was you.
It has been proven that light travels at slower speeds through some mediums.
It's called refraction.
Is it not possible that a medium may exist in which light moves faster? Might the severe gravitational forces of a black hole cause light to move faster than c as it pulls it in? If that light is pulled in faster than c is that light now moving backward in time?
No. It is not possible. If you think it's possible, then you need to tell me what you get when you divide one by zero and then you need to tell me what you get when you divide one by an imaginary number.
Just because the process an atomic clock uses for its timing operates differently based on gravity does not mean that time itself is moving at a different speed. A better experiment would be to take multiple timing devices along for the trip and see if they are all off by the same amount of time when they return.
It's not the clock, Steve. Gravity affects time itself. That's what the equations say. It doesn't have anything to do with what sort of clock you carry.
But it does. If you used a clock that uses the force of gravity as part of its mechanical method for tracking time it would cease to work while in free fall even though time is still moving. As far as I am concerned the experiment with the atomic clocks on airplanes in inconclusive. It only shows that the clocks worked at different speeds based on the influence of gravity not that time itself moved at different speeds.
Math has been wrong before and some math works only until you hit a certain point and then it breaks down.
When? Tell me what point you're talking about.
More practical examples of the failure of classical mechanics on an engineering scale are conduction by quantum tunneling in tunnel diodes and very narrow transistor gates in integrated circuits.
Theories (and the math behind them) evolve as new data comes along. Divide zero by one? I don't have to do that. The physics inside a black hole may not be the same physics as outside of a black hole.
More practical examples of the failure of classical mechanics on an engineering scale are conduction by quantum tunneling in tunnel diodes and very narrow transistor gates in integrated circuits.
1. That's not a point at which math breaks down or the math is wrong. That's where classical physics doesn't give the right answer. That's why we have modern physics. What does modern physics use? Math.
2. What do you think they're using there to express why there's a limit on the applicability of classical mechanics? French? It's more math!
3. Seriously, you don't know what you're talking about.
Just because the process an atomic clock uses for its timing operates differently based on gravity does not mean that time itself is moving at a different speed. A better experiment would be to take multiple timing devices along for the trip and see if they are all off by the same amount of time when they return.
It's not the clock, Steve. Gravity affects time itself. That's what the equations say. It doesn't have anything to do with what sort of clock you carry.
But it does. If you used a clock that uses the force of gravity as part of its mechanical method for tracking time it would cease to work while in free fall even though time is still moving. As far as I am concerned the experiment with the atomic clocks on airplanes in inconclusive. It only shows that the clocks worked at different speeds based on the influence of gravity not that time itself moved at different speeds.
GODAMMIT STEVE! Look at the math! It has nothing to do with the goddamn clock!
Theories (and the math behind them) evolve as new data comes along. Divide zero by one? I don't have to do that. The physics inside a black hole may not be the same physics as outside of a black hole.
That's not what you said. You said:
Math has been wrong before and some math works only until you hit a certain point and then it breaks down.
What you just said is completely unresponsive to my question. Show me what you're talking about.
I don't know why you're talking about physics inside a black fucking hole, unless you're trying to describe the dead space between your ears. You most certainly do have to divide one by zero if you want to describe what happens when something propagates at the speed of light. THAT'S WHAT MAKES IT IMPOSSIBLE!
I would just like to say that time dilation is only time travel in the normal sense but faster, still going from moment to moment. If you go over the speed of light you begin needing to add in more time in order to keep the speed in the "speed = distance / time" equation happy (at or under the speed of light). Time is compressing (dilating) so that you have more time to go faster than light in. This is, at least, my understanding.
Remember, you cannot overtake a photon. If you keep accelerating after it you will never catch up with it; The universe will add in extra time for it to get away if you go faster than light. In practice, you are capped at light speed.
I don't know why you're talking about physics inside a black fucking hole, unless you're trying to describe the dead space between your ears. You most certainly do have to divide one by zero if you want to describe what happens when something propagates at the speed of light. THAT'S WHAT MAKES IT IMPOSSIBLE!
That's where the math breaks down.
It is generally considered that it is impossible for any information or matter to travel faster than c. The equations of relativity show that, for an object travelling faster than c, some physical quantities would be not represented by real numbers. However, there are many physical situations in which speeds greater than c are encountered.
I also bring up black holes because they have very strong gravitational fields. If they are strong enough to prevent light from escaping than why is it so hard to imagine that they might also be strong enough to pull light into themselves at a speed greater than c? Or it is just that c will always be the speed light travels no matter what speed that is?
Remember, you cannot overtake a photon. If you keep accelerating after it you will never catch up with it; The universe will add in extra time for it to get away if you go faster than light. In practice, you are capped at light speed.
Can a photon be captured? Is the energy that moves a photon constant? If you catch and release the photon will it immediately resume motion at c?
It is important to note, however, that the speed at which the photons travel is always the same. That is, the speed of light, commonly designated as c, does not change. The light appears to travel more slowly while traversing a medium due to the frequent interactions of the photons with matter. This is similar to a train that, while moving, travels at a constant velocity. If such a train were to travel on a set of tracks with many stops it would appear to be moving more slowly overall, i.e. have a lower average velocity, despite having a constant higher velocity while moving.
Isn't light, being the most speedy of all things, that way because it has zero rest mass, allowing it to travel through vacuums uninhibited by the natural laws of gravity? Traveling faster than the speed of light through sheer force is the same as swimming in a river where the current gets progressively stronger the faster you try to swim, now imagine you have the power to swim at the speed of light but the current of the water is actually stopping you from doing so, because it gets stronger the faster you try to swim.
So unless someone can create a machine that actually stops gravity effecting an object, forcing the speed of light is impossible... we either have to negate gravity so it doesn't effect our space ship or find another way to get to the planet with the hot 3 boobed women.
Comments
I should have used the word example instead of reference. For those of you who have played it RA and RA2 extend world war 2 which, while some would argue was better than genocide, may not have been. The moral: While the past was shit, it could have been much worse.
Is time slowing down or are you slowing down? Is it just your perception of time that is slowing down?
I have never been able to accept the idea that time slows down as you approach the speed of light. I can accept that your perception of time slows down but not that time itself slows down. If time slowed down than once you reached the speed of light you would stop moving. As long as the vessel you are in continues to move at speed time is not slowing down or stopping.
If you had a powerful enough telescope you could (theoretically) travel faster than the speed of light and look behind you at the Earth and see what appears to be time in reverse. Time is not in reverse it is just that the light you are seeing is not travelling as fast as you are and you are seeing what happened in the past. This is no different than looking through a telescope on Earth at distant galaxies. We are not seeing them as they are today but as they were many years ago (depends on how many light years away they are.)
I have no doubt that the speed of light will eventually be surpassed through technology.
As to killing Hitler... I remember an issue of G.I. Combat (or some other 70's war comic) where they sent a lone gunman back in time to kill Hitler. I don't remember if he killed him or not but, the Nazis took the assassins gear, copied it and used it to win the war. I think there was some cheesy Sci-Fi movie (Philadelphia Experiment 2?) where an American Stealth Bomber ended up being transported back to Hitler's Germany with a few modern nukes on board. Germany dropped them on NYC and DC and that was the end of World War 2.
However, the drawback of such a design would be the insanely large requirements for energy.
Here is an image of how such a bending of space would look like:
The information would not be received before it was sent. Breaking c does not result in time travel. The information may "appear" to have been received before it was sent only because the receiver would receive the information before they would be able to see (or observe) the sender send it (providing they had a good enough optics system to see the sender perform the task from a distance of several light seconds or more).
Let me put forth this hypothetical:
What if you had a wire that was one light year in length. It is made out of an indestructible substance that neither contracts nor expands. This wire is inside a hollow tube of the same material and both ends of the tubes open into rooms that are one light year apart. (I know this is impossible because there would be no way to keep these two rooms stationary and connected over such a vast distance but humor me.)
If you were to pull this wire in room A the person in room B would observe the wire moving at the same time even though the "I'm pulling the wire" message (traveling my radio wave at the speed of light) would not reach the other room for 1 year.
The wire is not moving at the speed of light, it is simply such a long wire (with special properties) that it can be used to transfer information faster than the speed of light.
Yes, this is 101% total science fiction and no such substance exists with the tensile strength to work in this way. The weight of the wire would prevent it from being pulled or it would require so much energy to move the wire that it would not be practical.
I can believe that science will allow us to travel faster than the speed of light but I can't believe in time travel (except into the future, which we do every day).
Imagine a piece of paper. You want to get from one end of the paper to the other. Instead of walking across the entire paper, just fold the paper in half, jump to the other side, then unfold it.
Yes, my hypothetical wire is also impossible. The hypothetical wire would not be subject to this. It does not stretch or compress. source
Yes, the clock on the plane was slightly faster but was time moving at a different speed or is it a case of gravity having an effect on the way the clock works? Does an atomic clock track time itself or something that can be influenced by gravitational forces?
Math has been wrong before and some math works only until you hit a certain point and then it breaks down. I simply can not accept that passing the speed of light involves time travel.
It has been proven that light travels at slower speeds through some mediums. Diamond in particular slows down light to a very high degree. Even fiber optic cables slow down light to some degree. Is it not possible that a medium may exist in which light moves faster? Might the severe gravitational forces of a black hole cause light to move faster than c as it pulls it in? If that light is pulled in faster than c is that light now moving backward in time?
Weren't you the one who thought you needed calculus to solve a quadratic equation? I don't think you have any basis to be criticizing the mathematics of Relativity. Yeah, that was you. It's called refraction. No. It is not possible. If you think it's possible, then you need to tell me what you get when you divide one by zero and then you need to tell me what you get when you divide one by an imaginary number.
Theories (and the math behind them) evolve as new data comes along. Divide zero by one? I don't have to do that. The physics inside a black hole may not be the same physics as outside of a black hole.
2. What do you think they're using there to express why there's a limit on the applicability of classical mechanics? French? It's more math!
3. Seriously, you don't know what you're talking about. GODAMMIT STEVE! Look at the math! It has nothing to do with the goddamn clock! That's not what you said. You said: What you just said is completely unresponsive to my question. Show me what you're talking about.
I don't know why you're talking about physics inside a black fucking hole, unless you're trying to describe the dead space between your ears. You most certainly do have to divide one by zero if you want to describe what happens when something propagates at the speed of light. THAT'S WHAT MAKES IT IMPOSSIBLE!
Remember, you cannot overtake a photon. If you keep accelerating after it you will never catch up with it; The universe will add in extra time for it to get away if you go faster than light. In practice, you are capped at light speed.
I also bring up black holes because they have very strong gravitational fields. If they are strong enough to prevent light from escaping than why is it so hard to imagine that they might also be strong enough to pull light into themselves at a speed greater than c? Or it is just that c will always be the speed light travels no matter what speed that is?
So unless someone can create a machine that actually stops gravity effecting an object, forcing the speed of light is impossible... we either have to negate gravity so it doesn't effect our space ship or find another way to get to the planet with the hot 3 boobed women.