Superstition
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Ian Shlasko wrote:
it just doesn't make sense to me that it should move the same speed, regardless of the frame of reference. I mean, nothing else in nature follows that rule, right?
Not that rule, because that is not the controlling rule. The controlling rule is that all the other rules, including f=ma, apply equally, regardless of your frame of reference. If I am going along at 0.9_c_, relative to you, all the rules apply to me, which means light goes at the speed of light in my frame of reference. Because I am not going 0.9c! I am going 0.9_c_ relative to you! You are going 0.9_c_ relative to ME!
Ian Shlasko wrote:
as an object approaches the speed of light, its mass approaches infinity, so it's impossible to add more velocity
f=ma: 1 kg m/s^2 requires 1 newton. A kg approaches c relative to you At some point, for you, its time dilation reaches 10. You apply a newton to the 1 kg You expect its acceleration to be 1m/s^2. And it is. But it's time dilation is 10, so 10 seconds of your time pass for 1 sec to pass for it, and before its velocity has increased by 1m/s. Turn it around, you have to apply 10 newtons for 1 second of your time to get that same 1m/s change in v. So to you, it seems the mass has increased by a factor of 10, the same as the time dilation.
Ian Shlasko wrote:
So I wonder why light should ALWAYS move at the same speed (Modified by the medium)
Careful, light does not require a medium. But yes, c, in a medium, varies.
Ian Shlasko wrote:
Maybe a vacuum isn't really a vacuum, and the speed of light is really just the terminal velocity of an EM wave.
Light ALWAYS goes c, and never slower. c varies per above.
Opacity, the new Transparency.
RichardM1 wrote:
The controlling rule is that all the other rules, including f=ma, apply equally, regardless of your frame of reference. If I am going along at 0.9c, relative to you, all the rules apply to me, which means light goes at the speed of light in my frame of reference.
Ok... Well I'm sure you've heard this one before... If two ships are moving toward each other, each moving at 0.9c relative to a stationary observer, then they SHOULD be moving at 1.8c relative to each other... General relativity states that they're only moving at 0.9c relative to each other... But if they're 0.9 light minutes apart, is that stationary observer in the middle (Hopefully not TOO close to the middle) going to see them crash in one minute or 30 seconds? If the latter, then it just doesn't make sense to say that they're only moving 0.9c relative to each other. It might make sense that we only PERCEIVE them moving at 0.9c, even though the actual relative speed is twice that.
RichardM1 wrote:
So to you, it seems the mass has increased by a factor of 10, the same as the time dilation.
But again... That's perceived acceleration... If your destination is 0.9 light minutes away, and you're moving at 0.9c... If you apply an additional force, will you crash into the planet at your destination in one minute or less than one minute, as observed by a third party? For some reason, I keep coming back to things crashing into each other... I must be in a weird mood...
RichardM1 wrote:
Careful, light does not require a medium. But yes, c, in a medium, varies.
Understood... Just heading off the obvious "It only moves at 3x10^8m/s in a vacuum" nitpick :)
RichardM1 wrote:
Light ALWAYS goes c, and never slower. c varies per above.
The way I've always understood it was that c ~= 3x10^8m/s = Speed of light in a vacuum. It's a constant. Light travels slower than c through a denser medium.
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Author of the Guardians Saga (Sci-Fi/Fantasy novels) -
Ian Shlasko wrote:
I see nothing that would suggest any sort of thinking creator, and since no one has been able to present any real evidence of one, I discount it as improbable.
Do you see anything that precludes a thinking creator? You are applying bias. You shouldn't discount it a improbable, you should admit you have not data that requires, or precludes, a thinking creator, and that you have no idea what the probability is.
Opacity, the new Transparency.
RichardM1 wrote:
Do you see anything that precludes a thinking creator? You are applying bias. You shouldn't discount it a improbable, you should admit you have not data that requires, or precludes, a thinking creator, and that you have no idea what the probability is.
So should I apply equal probability to the chance that the universe was created by a metaphysical extrapolation of Chuck Norris's beard? (Sorry, it just popped into my head) That the entire universe is actually about to be sneezed out the nose of the Great Green Arkelseizure? (There, made up for it with a H2G2 reference) There's no way to disprove any of those theories. Basically, since we have no way of knowing what's outside the universe, if anything, then any theory has an equal probability. Since the number of possible theories is limited only by our imagination, I think we can assume that number to be, for all intents and purposes, infinite. If all theories are equally likely, than the chance of a particular theory being correct is inversely proportional to the number of theories, hence it approaches zero. Of course, one theory has to be correct, by definition, though we may not have thought of it yet. Until we have some sort of evidence to adjust the probabilities, I stick to the default position of all of these theories being equally improbable. EDIT: Stupid typo.
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Author of the Guardians Saga (Sci-Fi/Fantasy novels)modified on Monday, March 22, 2010 4:12 PM
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RichardM1 wrote:
Do you see anything that precludes a thinking creator? You are applying bias. You shouldn't discount it a improbable, you should admit you have not data that requires, or precludes, a thinking creator, and that you have no idea what the probability is.
So should I apply equal probability to the chance that the universe was created by a metaphysical extrapolation of Chuck Norris's beard? (Sorry, it just popped into my head) That the entire universe is actually about to be sneezed out the nose of the Great Green Arkelseizure? (There, made up for it with a H2G2 reference) There's no way to disprove any of those theories. Basically, since we have no way of knowing what's outside the universe, if anything, then any theory has an equal probability. Since the number of possible theories is limited only by our imagination, I think we can assume that number to be, for all intents and purposes, infinite. If all theories are equally likely, than the chance of a particular theory being correct is inversely proportional to the number of theories, hence it approaches zero. Of course, one theory has to be correct, by definition, though we may not have thought of it yet. Until we have some sort of evidence to adjust the probabilities, I stick to the default position of all of these theories being equally improbable. EDIT: Stupid typo.
Proud to have finally moved to the A-Ark. Which one are you in?
Author of the Guardians Saga (Sci-Fi/Fantasy novels)modified on Monday, March 22, 2010 4:12 PM
Ian Shlasko wrote:
So should I apply equal probability to the chance that the universe was created by a metaphysical extrapolation of Chuck Norris's beard?
Yes. You assign their probabilities the same designation: You admit that we don't know the probability of any particular metaphysical possibility. On the other hand, anything that is part of the created universe is known to have a zero chance of having created the universe. Except Chuck Norris.
Ian Shlasko wrote:
I stick to the default position of all of these theories being equally improbable.
Unknown is not equal, without asking you favor any.
Opacity, the new Transparency.
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Ian Shlasko wrote:
So should I apply equal probability to the chance that the universe was created by a metaphysical extrapolation of Chuck Norris's beard?
Yes. You assign their probabilities the same designation: You admit that we don't know the probability of any particular metaphysical possibility. On the other hand, anything that is part of the created universe is known to have a zero chance of having created the universe. Except Chuck Norris.
Ian Shlasko wrote:
I stick to the default position of all of these theories being equally improbable.
Unknown is not equal, without asking you favor any.
Opacity, the new Transparency.
RichardM1 wrote:
Unknown is not equal, without asking you favor any.
If we have no actual knowledge, then we can't assign a higher probability to one theory than to another. Without any data, the "creator" theory is no more likely than the "snot" theory, which is no more likely than the "airport locker" theory (Men in Black 2).
Proud to have finally moved to the A-Ark. Which one are you in?
Author of the Guardians Saga (Sci-Fi/Fantasy novels) -
RichardM1 wrote:
The controlling rule is that all the other rules, including f=ma, apply equally, regardless of your frame of reference. If I am going along at 0.9c, relative to you, all the rules apply to me, which means light goes at the speed of light in my frame of reference.
Ok... Well I'm sure you've heard this one before... If two ships are moving toward each other, each moving at 0.9c relative to a stationary observer, then they SHOULD be moving at 1.8c relative to each other... General relativity states that they're only moving at 0.9c relative to each other... But if they're 0.9 light minutes apart, is that stationary observer in the middle (Hopefully not TOO close to the middle) going to see them crash in one minute or 30 seconds? If the latter, then it just doesn't make sense to say that they're only moving 0.9c relative to each other. It might make sense that we only PERCEIVE them moving at 0.9c, even though the actual relative speed is twice that.
RichardM1 wrote:
So to you, it seems the mass has increased by a factor of 10, the same as the time dilation.
But again... That's perceived acceleration... If your destination is 0.9 light minutes away, and you're moving at 0.9c... If you apply an additional force, will you crash into the planet at your destination in one minute or less than one minute, as observed by a third party? For some reason, I keep coming back to things crashing into each other... I must be in a weird mood...
RichardM1 wrote:
Careful, light does not require a medium. But yes, c, in a medium, varies.
Understood... Just heading off the obvious "It only moves at 3x10^8m/s in a vacuum" nitpick :)
RichardM1 wrote:
Light ALWAYS goes c, and never slower. c varies per above.
The way I've always understood it was that c ~= 3x10^8m/s = Speed of light in a vacuum. It's a constant. Light travels slower than c through a denser medium.
Proud to have finally moved to the A-Ark. Which one are you in?
Author of the Guardians Saga (Sci-Fi/Fantasy novels)Ian Shlasko wrote:
Ok... Well I'm sure you've heard this one before... If two ships are moving toward each other, each moving at 0.9c relative to a stationary observer, then they SHOULD be moving at 1.8c relative to each other... General relativity states that they're only moving at 0.9c relative to each other...
"SHOULD be" is in non-relativistic terms. I can't give you the equations for this, but I know that applying special relativity gives you an approach velocity of less than c but greater than 0.9_c_. There is time dilation and space contaction going on between the two ships, not just between the other observer and the ships.
Ian Shlasko wrote:
But if they're 0.9 light minutes apart, is that stationary observer in the middle (Hopefully not TOO close to the middle) going to see them crash in one minute or 30 seconds? If the latter, then it just doesn't make sense to say that they're only moving 0.9c relative to each other. It might make sense that we only PERCEIVE them moving at 0.9c, even though the actual relative speed is twice that.
Only the other observer sees the distance as being 0.9 light minutes. Time dilation causes space contraction. If the other observer sees the ship moving at 0.9_c_, and 0.45 light minutes away, the ship sees the other observer moving at 0.9_c_, but at a shorter distance, inversely proportional to the time dilation. Since the distance is less than 0.45 light minutes, the speed required for them both to cross the distance is less, so their relative velocity is less than c.
Opacity, the new Transparency.
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Ian Shlasko wrote:
Ok... Well I'm sure you've heard this one before... If two ships are moving toward each other, each moving at 0.9c relative to a stationary observer, then they SHOULD be moving at 1.8c relative to each other... General relativity states that they're only moving at 0.9c relative to each other...
"SHOULD be" is in non-relativistic terms. I can't give you the equations for this, but I know that applying special relativity gives you an approach velocity of less than c but greater than 0.9_c_. There is time dilation and space contaction going on between the two ships, not just between the other observer and the ships.
Ian Shlasko wrote:
But if they're 0.9 light minutes apart, is that stationary observer in the middle (Hopefully not TOO close to the middle) going to see them crash in one minute or 30 seconds? If the latter, then it just doesn't make sense to say that they're only moving 0.9c relative to each other. It might make sense that we only PERCEIVE them moving at 0.9c, even though the actual relative speed is twice that.
Only the other observer sees the distance as being 0.9 light minutes. Time dilation causes space contraction. If the other observer sees the ship moving at 0.9_c_, and 0.45 light minutes away, the ship sees the other observer moving at 0.9_c_, but at a shorter distance, inversely proportional to the time dilation. Since the distance is less than 0.45 light minutes, the speed required for them both to cross the distance is less, so their relative velocity is less than c.
Opacity, the new Transparency.
RichardM1 wrote:
Only the other observer sees the distance as being 0.9 light minutes. Time dilation causes space contraction. If the other observer sees the ship moving at 0.9c, and 0.45 light minutes away, the ship sees the other observer moving at 0.9c, but at a shorter distance, inversely proportional to the time dilation. Since the distance is less than 0.45 light minutes, the speed required for them both to cross the distance is less, so their relative velocity is less than c.
Ok, now you've lost me completely. Forget how they see each other for a second, and focus on the stationary observer... They reach the starting line, going 0.9c, at the same time he starts his stopwatch. Each is going 0.9c, and they're 0.9 light minutes apart. Ignoring the fact that they're near light speed, they would each reach the center in 30 seconds, and the explosion would be very entertaining... So is the guy's stopwatch going to read 30 seconds, or does the theory predict that it would take longer?
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Author of the Guardians Saga (Sci-Fi/Fantasy novels) -
RichardM1 wrote:
Unknown is not equal, without asking you favor any.
If we have no actual knowledge, then we can't assign a higher probability to one theory than to another. Without any data, the "creator" theory is no more likely than the "snot" theory, which is no more likely than the "airport locker" theory (Men in Black 2).
Proud to have finally moved to the A-Ark. Which one are you in?
Author of the Guardians Saga (Sci-Fi/Fantasy novels) -
Ian Shlasko wrote:
If we have no actual knowledge, then we can't assign a higher probability to one theory than to another.
Right. Unknown. You can't say they are different. You can't say they are the same. Unknown.
Opacity, the new Transparency.
Hmm... Ok, point ceded. Technically, we can't assign a statistical probability. The earlier point remains though... What makes the "creator" theory any more plausible than the "airport locker" theory, for example? Why does the "creator" theory merit being disproved instead of ignored, while the "airport locker" theory is simply disregarded? Is it because the "airport locker" theory comes from a work that identifies itself as fiction? My novels are based on a "multiple universes and dimensions" theory. If I claimed that my novels were fact instead of fiction, would that suddenly be as plausible as the "creator" theory? Technically, it can't be disproved either, aside from the fact that I openly admit that I dreamed it up and that it's a fabrication.
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Author of the Guardians Saga (Sci-Fi/Fantasy novels) -
RichardM1 wrote:
Only the other observer sees the distance as being 0.9 light minutes. Time dilation causes space contraction. If the other observer sees the ship moving at 0.9c, and 0.45 light minutes away, the ship sees the other observer moving at 0.9c, but at a shorter distance, inversely proportional to the time dilation. Since the distance is less than 0.45 light minutes, the speed required for them both to cross the distance is less, so their relative velocity is less than c.
Ok, now you've lost me completely. Forget how they see each other for a second, and focus on the stationary observer... They reach the starting line, going 0.9c, at the same time he starts his stopwatch. Each is going 0.9c, and they're 0.9 light minutes apart. Ignoring the fact that they're near light speed, they would each reach the center in 30 seconds, and the explosion would be very entertaining... So is the guy's stopwatch going to read 30 seconds, or does the theory predict that it would take longer?
Proud to have finally moved to the A-Ark. Which one are you in?
Author of the Guardians Saga (Sci-Fi/Fantasy novels)Ian Shlasko wrote:
So is the guy's stopwatch going to read 30 seconds, or does the theory predict that it would take longer?
There is nothing special about him. Things will have certain measures in his frame of reference. The distance is 0.9 light minutes between the two ship. The ships are each moving 0.9_c_ relative to the him. The time is 30 seconds to impact in his frame of reference. Only one of these are true for the other two frames of reference. Each other frame of reference see the center guy moving at 0.9_c_, relative to themselves. The measured distance between ships is not 0.9 light minutes in their frame of reference. The distance to impact is less than 0.45 light minutes. The time to impact is less than 30 seconds. All these measurements are correct. Both distance and time change.
Opacity, the new Transparency.
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Hmm... Ok, point ceded. Technically, we can't assign a statistical probability. The earlier point remains though... What makes the "creator" theory any more plausible than the "airport locker" theory, for example? Why does the "creator" theory merit being disproved instead of ignored, while the "airport locker" theory is simply disregarded? Is it because the "airport locker" theory comes from a work that identifies itself as fiction? My novels are based on a "multiple universes and dimensions" theory. If I claimed that my novels were fact instead of fiction, would that suddenly be as plausible as the "creator" theory? Technically, it can't be disproved either, aside from the fact that I openly admit that I dreamed it up and that it's a fabrication.
Proud to have finally moved to the A-Ark. Which one are you in?
Author of the Guardians Saga (Sci-Fi/Fantasy novels)Ian Shlasko wrote:
Is it because the "airport locker" theory comes from a work that identifies itself as fiction? My novels are based on a "multiple universes and dimensions" theory. If I claimed that my novels were fact instead of fiction, would that suddenly be as plausible as the "creator" theory? Technically, it can't be disproved either, aside from the fact that I openly admit that I dreamed it up and that it's a fabrication.
The published observations give us no hard indication what the mechanism for creation was, before the inflationary stage coming out of a singularity. You are not the first to think up multiple 'verses and dimensions. There are theories that indicate it as a possibility, but no proof. But they are not mutually exclusive with a Creator. One is method, the other is cause. God may have used a multiverse, locker, or created out of nothing, using the big bang. Thank you for asking these questions, I had not realized that before. :-D
Opacity, the new Transparency.
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Ian Shlasko wrote:
Is it because the "airport locker" theory comes from a work that identifies itself as fiction? My novels are based on a "multiple universes and dimensions" theory. If I claimed that my novels were fact instead of fiction, would that suddenly be as plausible as the "creator" theory? Technically, it can't be disproved either, aside from the fact that I openly admit that I dreamed it up and that it's a fabrication.
The published observations give us no hard indication what the mechanism for creation was, before the inflationary stage coming out of a singularity. You are not the first to think up multiple 'verses and dimensions. There are theories that indicate it as a possibility, but no proof. But they are not mutually exclusive with a Creator. One is method, the other is cause. God may have used a multiverse, locker, or created out of nothing, using the big bang. Thank you for asking these questions, I had not realized that before. :-D
Opacity, the new Transparency.
RichardM1 wrote:
You are not the first to think up multiple 'verses and dimensions. There are theories that indicate it as a possibility, but no proof.
Oh, I know that... Never said I was the first... It's the other ideas in my novel that are original :)
RichardM1 wrote:
But they are not mutually exclusive with a Creator. One is method, the other is cause. God may have used a multiverse, locker, or created out of nothing, using the big bang.
See, you're assuming a creator and just fitting one into all of the blanks... I'm operating under the assumption of nothingness, and looking for proof before moving from there.
Proud to have finally moved to the A-Ark. Which one are you in?
Author of the Guardians Saga (Sci-Fi/Fantasy novels) -
Ian Shlasko wrote:
So is the guy's stopwatch going to read 30 seconds, or does the theory predict that it would take longer?
There is nothing special about him. Things will have certain measures in his frame of reference. The distance is 0.9 light minutes between the two ship. The ships are each moving 0.9_c_ relative to the him. The time is 30 seconds to impact in his frame of reference. Only one of these are true for the other two frames of reference. Each other frame of reference see the center guy moving at 0.9_c_, relative to themselves. The measured distance between ships is not 0.9 light minutes in their frame of reference. The distance to impact is less than 0.45 light minutes. The time to impact is less than 30 seconds. All these measurements are correct. Both distance and time change.
Opacity, the new Transparency.
Ok, so from the POV of an independent observer, what would happen if one of them turned on their rocket engines? You can see where I'm going with this... From an independent perspective, could it accelerate to the speed of light?
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Author of the Guardians Saga (Sci-Fi/Fantasy novels) -
Ok, so from the POV of an independent observer, what would happen if one of them turned on their rocket engines? You can see where I'm going with this... From an independent perspective, could it accelerate to the speed of light?
Proud to have finally moved to the A-Ark. Which one are you in?
Author of the Guardians Saga (Sci-Fi/Fantasy novels)Ian Shlasko wrote:
Ok, so from the POV of an independent observer, what would happen if one of them turned on their rocket engines? You can see where I'm going with this... From an independent perspective, could it accelerate to the speed of light?
And that is the crux of your problem understanding it. There is no independent observer/perspective. There is no special frame of reference in which things are not moving. All frames of reference are relative to all others. All the same rules apply to all frames of reference. Suppose that X's frame of reference is going at 0.99999999_c_ with respect to your frame of reference. In X's frame of reference, you are going at 0.99999999_c_, in the opposite direction. X can accelerate to a new frame of reference that is 0.1_c_, or 0.5_c_, faster than X's previous frame of reference, in the same direction you see X going. The math may work out that the difference in velocity between your frame of reference and X's will be 0.9999999999_c_, or 0.99999999999999_c_, but it will never hit c. And, in each frame of reference, any measurement of the speed of light will show it to be c, relative to that frame of reference, in all directions.
Opacity, the new Transparency.
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RichardM1 wrote:
You are not the first to think up multiple 'verses and dimensions. There are theories that indicate it as a possibility, but no proof.
Oh, I know that... Never said I was the first... It's the other ideas in my novel that are original :)
RichardM1 wrote:
But they are not mutually exclusive with a Creator. One is method, the other is cause. God may have used a multiverse, locker, or created out of nothing, using the big bang.
See, you're assuming a creator and just fitting one into all of the blanks... I'm operating under the assumption of nothingness, and looking for proof before moving from there.
Proud to have finally moved to the A-Ark. Which one are you in?
Author of the Guardians Saga (Sci-Fi/Fantasy novels)Ian Shlasko wrote:
See, you're assuming a creator and just fitting one into all of the blanks
No, I am not fitting one into all the blanks. I look at the Bible and see how it meshes with observation. I don't see God fitting into the spaces 'between' science. I believe God built EVERYTHING. He put together quantum mechanics, He knows relativity, since He made the rules. Again, you are looking at the method of creation, I am also looking at the cause. But I'm not trying to convince you, I'm explaining what I believe and why. I don't believe I can convince anyone of God's existence. You either see proof through your observation, or you don't. If you see it, you decide to believe it, or you don't. I looked at my observations, and, to me, it was proof of God. So I believe. YMMV.
Opacity, the new Transparency.
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Ian Shlasko wrote:
Ok, so from the POV of an independent observer, what would happen if one of them turned on their rocket engines? You can see where I'm going with this... From an independent perspective, could it accelerate to the speed of light?
And that is the crux of your problem understanding it. There is no independent observer/perspective. There is no special frame of reference in which things are not moving. All frames of reference are relative to all others. All the same rules apply to all frames of reference. Suppose that X's frame of reference is going at 0.99999999_c_ with respect to your frame of reference. In X's frame of reference, you are going at 0.99999999_c_, in the opposite direction. X can accelerate to a new frame of reference that is 0.1_c_, or 0.5_c_, faster than X's previous frame of reference, in the same direction you see X going. The math may work out that the difference in velocity between your frame of reference and X's will be 0.9999999999_c_, or 0.99999999999999_c_, but it will never hit c. And, in each frame of reference, any measurement of the speed of light will show it to be c, relative to that frame of reference, in all directions.
Opacity, the new Transparency.
See, that's the kind of reply I always get... To quote a line from Babylon 5... Every answer is a reply, but not every reply is an answer. If you're moving at .99999c toward me, relative to me, and you hit a point one light minute away at a scheduled time, then kick in the afterburners, will you reach me before my stopwatch hits 60 seconds? Regardless of how the traveler perceives the journey, if you don't rely on observing the starting point (Synchronizing watches instead), it doesn't take complex math for someone at the destination to see when you arrive. I understand that there's no "stationary", as if I'm standing still relative to the sun, I'm still moving quite fast relative to the galactic center, and still faster relative to the estimated center of the universe... But given a fixed frame of reference, it should still be possible to avoid the perception game and see whether the elapsed time is more or less than basic f=ma would imply.
Proud to have finally moved to the A-Ark. Which one are you in?
Author of the Guardians Saga (Sci-Fi/Fantasy novels) -
See, that's the kind of reply I always get... To quote a line from Babylon 5... Every answer is a reply, but not every reply is an answer. If you're moving at .99999c toward me, relative to me, and you hit a point one light minute away at a scheduled time, then kick in the afterburners, will you reach me before my stopwatch hits 60 seconds? Regardless of how the traveler perceives the journey, if you don't rely on observing the starting point (Synchronizing watches instead), it doesn't take complex math for someone at the destination to see when you arrive. I understand that there's no "stationary", as if I'm standing still relative to the sun, I'm still moving quite fast relative to the galactic center, and still faster relative to the estimated center of the universe... But given a fixed frame of reference, it should still be possible to avoid the perception game and see whether the elapsed time is more or less than basic f=ma would imply.
Proud to have finally moved to the A-Ark. Which one are you in?
Author of the Guardians Saga (Sci-Fi/Fantasy novels)Sometimes, the reply is an answer, but you don't understand.
Ian Shlasko wrote:
Synchronizing watches instead
I synchronize my watch with a guy in ship 1, just as it passes the 0.45 light minute mark*. When he gets to me, my watch says 30 seconds has elapsed. His watch says less than 30 seconds has elapsed. *This is harder than it sounds, since the point I measure as being 0.45 light minutes away, is not the same one HE measures as 0.45 light minutes away. The point he measures as 0.45 light minutes away from me, when I measure it, is greater then 0.45 light minutes away. Space and time are not constant when compared across multiple frames of reference. --------------------------- Real numbers. A ship going by the Earth is heading towards a star 12.5 light years away, at v = 0.8_c_ relative to an observer on earth. The ship sees a time dilation of
sqrt(1-(_v_^2/_c_^2), or 0.6. O.6*12.5 = 7.5 years transit time for the crew of the ship. The crew sees the planet approaching at 0.8_c_. In the crew's frame of reference, the travel time is 7.5 years, and v = 0.8_c_. 7.5 years * 0.8_c_ equals 6.0 light years, so the distance from earth to the star they are traveling to is 6 light years. It REALLY is 6 light years in that frame of reference, not "appears to be" or tricks. 7.5 years REALLY have elapsed for the crew of the ship. If you take along a radio-isotope whose half life is 7.5 years, roughly half will have REALLY decayed.Opacity, the new Transparency.
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Sometimes, the reply is an answer, but you don't understand.
Ian Shlasko wrote:
Synchronizing watches instead
I synchronize my watch with a guy in ship 1, just as it passes the 0.45 light minute mark*. When he gets to me, my watch says 30 seconds has elapsed. His watch says less than 30 seconds has elapsed. *This is harder than it sounds, since the point I measure as being 0.45 light minutes away, is not the same one HE measures as 0.45 light minutes away. The point he measures as 0.45 light minutes away from me, when I measure it, is greater then 0.45 light minutes away. Space and time are not constant when compared across multiple frames of reference. --------------------------- Real numbers. A ship going by the Earth is heading towards a star 12.5 light years away, at v = 0.8_c_ relative to an observer on earth. The ship sees a time dilation of
sqrt(1-(_v_^2/_c_^2), or 0.6. O.6*12.5 = 7.5 years transit time for the crew of the ship. The crew sees the planet approaching at 0.8_c_. In the crew's frame of reference, the travel time is 7.5 years, and v = 0.8_c_. 7.5 years * 0.8_c_ equals 6.0 light years, so the distance from earth to the star they are traveling to is 6 light years. It REALLY is 6 light years in that frame of reference, not "appears to be" or tricks. 7.5 years REALLY have elapsed for the crew of the ship. If you take along a radio-isotope whose half life is 7.5 years, roughly half will have REALLY decayed.Opacity, the new Transparency.
RichardM1 wrote:
Sometimes, the reply is an answer, but you don't understand.
I understand the concept, at least partially... I just have trouble accepting the conclusions. It all seems completely illogical to me.
RichardM1 wrote:
If you take along a radio-isotope whose half life is 7.5 years, roughly half will have REALLY decayed.
That's an experiment I'd like to see. I can understand perspective changing, but actual time dilation just doesn't seem plausible to me. If it were possible to observe without relying on EM to carry the information... Of course that's the big trick, isn't it... Funny thing about the formulas though... If a ship was moving at close to light-speed, the time dilation by that formula would approach zero, so any journey at light-speed would basically be instantaneous to the travelers, no matter how far you went... Cross the universe in an instant, even though eons could have passed outside...
Proud to have finally moved to the A-Ark. Which one are you in?
Author of the Guardians Saga (Sci-Fi/Fantasy novels) -
RichardM1 wrote:
Sometimes, the reply is an answer, but you don't understand.
I understand the concept, at least partially... I just have trouble accepting the conclusions. It all seems completely illogical to me.
RichardM1 wrote:
If you take along a radio-isotope whose half life is 7.5 years, roughly half will have REALLY decayed.
That's an experiment I'd like to see. I can understand perspective changing, but actual time dilation just doesn't seem plausible to me. If it were possible to observe without relying on EM to carry the information... Of course that's the big trick, isn't it... Funny thing about the formulas though... If a ship was moving at close to light-speed, the time dilation by that formula would approach zero, so any journey at light-speed would basically be instantaneous to the travelers, no matter how far you went... Cross the universe in an instant, even though eons could have passed outside...
Proud to have finally moved to the A-Ark. Which one are you in?
Author of the Guardians Saga (Sci-Fi/Fantasy novels)Ian Shlasko wrote:
That's an experiment I'd like to see.
They have done it. They flew atomic clocks in both directions, around the world. They were able to detect the time dilation effect do to velocity in the flying clocks, and the time dilation resulting from the earths gravity well on the stationary clock.
Ian Shlasko wrote:
If a ship was moving at close to light-speed, the time dilation by that formula would approach zero, so any journey at light-speed would basically be instantaneous to the travelers, no matter how far you went.
You have correctly analyzed it. IF you were able to accelerate to those velocities, you would be able to 'cross the universe' in some arbitrarily small amount of time in your frame of reference. You would never actually get to the other side of the universe, since the universe is expanding under you, and growing outward at the speed of light on all its 'outer surface', if there is one.
Opacity, the new Transparency.
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Ian Shlasko wrote:
That's an experiment I'd like to see.
They have done it. They flew atomic clocks in both directions, around the world. They were able to detect the time dilation effect do to velocity in the flying clocks, and the time dilation resulting from the earths gravity well on the stationary clock.
Ian Shlasko wrote:
If a ship was moving at close to light-speed, the time dilation by that formula would approach zero, so any journey at light-speed would basically be instantaneous to the travelers, no matter how far you went.
You have correctly analyzed it. IF you were able to accelerate to those velocities, you would be able to 'cross the universe' in some arbitrarily small amount of time in your frame of reference. You would never actually get to the other side of the universe, since the universe is expanding under you, and growing outward at the speed of light on all its 'outer surface', if there is one.
Opacity, the new Transparency.
RichardM1 wrote:
IF you were able to accelerate to those velocities, you would be able to 'cross the universe' in some arbitrarily small amount of time in your frame of reference. You would never actually get to the other side of the universe, since the universe is expanding under you, and growing outward at the speed of light on all its 'outer surface', if there is one.
But then, how would you stop? I mean, if you can cross any distance in an instant, then theoretically, as soon as you attained light speed, the universe would end (If there is an end). An infinite amount of time would pass outside the ship just in the time it takes you to think, "Hey, I'm going at the speed of light!" So really it would be impossible to hit the brakes. It couldn't be automated, because time is effectively frozen for the ship as well as the passenger. You're not going to run out of fuel or power for the same reason. By the time you hit the button to engage the reverse thrusters, an infinite amount of time has already passed outside. Of course, light itself moves at the speed of light, obviously... So is time frozen for the individual photons? A photon has no perspective, being... a photon... but if it did, it would be in exactly that situation, unable to stop itself. Maybe that's why light always moves at the same speed :) Man... It's a good thing I don't do drugs... Imagine how much MORE screwed-up my thought process would be...
Proud to have finally moved to the A-Ark. Which one are you in?
Author of the Guardians Saga (Sci-Fi/Fantasy novels) -
RichardM1 wrote:
IF you were able to accelerate to those velocities, you would be able to 'cross the universe' in some arbitrarily small amount of time in your frame of reference. You would never actually get to the other side of the universe, since the universe is expanding under you, and growing outward at the speed of light on all its 'outer surface', if there is one.
But then, how would you stop? I mean, if you can cross any distance in an instant, then theoretically, as soon as you attained light speed, the universe would end (If there is an end). An infinite amount of time would pass outside the ship just in the time it takes you to think, "Hey, I'm going at the speed of light!" So really it would be impossible to hit the brakes. It couldn't be automated, because time is effectively frozen for the ship as well as the passenger. You're not going to run out of fuel or power for the same reason. By the time you hit the button to engage the reverse thrusters, an infinite amount of time has already passed outside. Of course, light itself moves at the speed of light, obviously... So is time frozen for the individual photons? A photon has no perspective, being... a photon... but if it did, it would be in exactly that situation, unable to stop itself. Maybe that's why light always moves at the same speed :) Man... It's a good thing I don't do drugs... Imagine how much MORE screwed-up my thought process would be...
Proud to have finally moved to the A-Ark. Which one are you in?
Author of the Guardians Saga (Sci-Fi/Fantasy novels)Ian Shlasko wrote:
But then, how would you stop? I mean, if you can cross any distance in an instant, then theoretically, as soon as you attained light speed, the universe would end (If there is an end). An infinite amount of time would pass outside the ship just in the time it takes you to think, "Hey, I'm going at the speed of light!"
Well, you can't actually accelerate to c, so you never get stuck in that situation. The other side of it is that you have to plan for it. You accelerate towards the target for a period of time, then you know you have to decelerate for that same amount of time in your changing frame of reference. This assumes your acceleration rate/deceleration rate are the same, which may not be true if you are burning fuel.
Opacity, the new Transparency.