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Thread: How Far is Far?

  1. #1 How Far is Far? 
    Time Lord zinjanthropos's Avatar
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    If the Milky Way contains 100 billion stars then is it really necessary to venture across inter galactic space? Wouldn't our own galaxy have enough to see and study than flying off to another one? There's enough stars to give everyone alive today 14 or 15 apiece. Isn't that enough for one person in a lifetime? Or is it the pursuit of discovering alien life and unexplored terrain that will drive us further from home?


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    When ancient explorers discovered other countries, even other continents, they did not stop there and explore everything before moving on. So it will be one day when space ships develop the ability to travel to other galaxies. They will go there as soon as they are able.

    As to alien life, we may discover that in the next decade. The easiest way will be by detecting "man-made" pollution in the atmosphere of planets around other stars. It is probably just a matter of our technology being sufficient to do that before it happens.


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    If you were to leave on an inter-galactic flight, then what would be some of the logistics involved? If travelling at close to c then you need to make sure you get to where you're going in one piece. I often wonder what would happen to a spaceship that's travelling close to c if it hit something. Plotting a course would require a pretty sophisticated computer wouldn't it? Also how would time dilation come into play? Do you even bother returning home? What about fuel?
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    First things first, there are some really cool planets close at hand, plus moons and smaller bodies. All in good time, and will human species still be recognizable to us when intergalactic possibilities materialize?
    The bravest are surely those who have the clearest vision of what is before them, glory and danger alike, and yet notwithstanding go out to meet it.- Thucydides
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    Quote Originally Posted by The Finger Prince View Post
    First things first, there are some really cool planets close at hand, plus moons and smaller bodies. All in good time, and will human species still be recognizable to us when intergalactic possibilities materialize?
    No doubt that's where we explore next. I'm merely asking if we really will need to go inter-galactic. You'd think 100 billion stars in our home galaxy would take a while to investigate. And if we're zipping around at tremendous speeds, then how do we plan a trip?
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    Prince confesses that at this point it is beyond his imagining, plus feels sleepy. While he dreams of planets you may ponder depths of intergalactic void, even at 100% c will take some time to cross, but human derived life must almost certainly have developed great longevity by that point. And long life in good health to you in your travels terrestrial and otherwise, dotcomrade Z.
    The bravest are surely those who have the clearest vision of what is before them, glory and danger alike, and yet notwithstanding go out to meet it.- Thucydides
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    Unless there is a major breakthrough in physics, humans will not get above 20% of light speed (0.2c) at most. This from an article on interstellar flight by a couple of NASA scientists.

    At 0.2 C, to travel to the Andromeda galaxy would take 10 million years. Rather a tall order!
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    We live in splendid isolation, and unless we discover something new, that is where we are going to stay.
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    I think most of us want to escape.
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    Humans tend to long for more so drive for searching newer galaxies is ever going practice...
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    Quote Originally Posted by meryem View Post
    Humans tend to long for more so drive for searching newer galaxies is ever going practice...
    If you've seen one galaxy then you've seen them all, no?
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    zinjanthropos. We do not need some kind of Star Trek technology to reach the stars. If we could build an engine which would put out one G force acceleration per second, it would take just under a year to reach almost light speed. We could then coast along for years till we have to spend nearly a year slowing down again. This would mean that we could reach a number of close stars within a decade. If time dilation works, not many years would pass for those on board depending on their cruising speed.
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    we cant see thing s closer than 25 centimeter and we can see things at infinite distance. (our eyes are designed in this way)
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    25mm? As hunters it was necessary that we see very distant things but not that we examine things very close up.
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    Maybe most modern people have lost our vision's capabilities, but when I see the minute details in, for instance, pre-european south and central america it's obvious that those people saw a LOT better than we do. I believe I saw in infrared once, and I know for sure that when I was about 30 years old I saw every star in its true colour.
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    Quote Originally Posted by Aristarchus in Exile View Post
    I think most of us want to escape.
    To where ?
    .
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    Quote Originally Posted by Dave Wilson View Post
    Quote Originally Posted by Aristarchus in Exile View Post
    I think most of us want to escape.
    To where ?
    The Land of Eternal Happiness would be nice.
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    Quote Originally Posted by zinjanthropos View Post
    If you were to leave on an inter-galactic flight, then what would be some of the logistics involved? If travelling at close to c then you need to make sure you get to where you're going in one piece. I often wonder what would happen to a spaceship that's travelling close to c if it hit something. Plotting a course would require a pretty sophisticated computer wouldn't it? Also how would time dilation come into play? Do you even bother returning home? What about fuel?
    Hi zinjan, fuel it not an issue, nor is something hitting you, the scenario you pose is motivated
    by your current understanding of technology.
    Antimatter propulsion systems will see spacecraft of the future compressing spacetime in front
    of the ship, and expanding it behind it, and beating M=MC squared.
    Am aware of the flack am going to get about this, but please consider the concept before
    jumping to a response.
    nokton.
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    Quote Originally Posted by Cyberia View Post
    zinjanthropos. We do not need some kind of Star Trek technology to reach the stars. If we could build an engine which would put out one G force acceleration per second, it would take just under a year to reach almost light speed. We could then coast along for years till we have to spend nearly a year slowing down again. This would mean that we could reach a number of close stars within a decade. If time dilation works, not many years would pass for those on board depending on their cruising speed.
    If going at such high rates of speed then the Twin Paradox scenario comes into play does it not? The travellers would have to consider this before they leave since it might mean saying goodbye to loved ones forever. Imagine leaving Earth with the most modern technology and returning as a museum piece. What you learned on the trip may be old news by the time you return.
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    Quote Originally Posted by nokton View Post
    Quote Originally Posted by zinjanthropos View Post
    If you were to leave on an inter-galactic flight, then what would be some of the logistics involved? If travelling at close to c then you need to make sure you get to where you're going in one piece. I often wonder what would happen to a spaceship that's travelling close to c if it hit something. Plotting a course would require a pretty sophisticated computer wouldn't it? Also how would time dilation come into play? Do you even bother returning home? What about fuel?
    Hi zinjan, fuel it not an issue, nor is something hitting you, the scenario you pose is motivated
    by your current understanding of technology.
    Antimatter propulsion systems will see spacecraft of the future compressing spacetime in front
    of the ship, and expanding it behind it, and beating M=MC squared.
    Am aware of the flack am going to get about this, but please consider the concept before
    jumping to a response.
    nokton.
    Not compressing space and time in front of the ship but sucking it into compressors and spitting it out the back end, like air into a jet,
    but using anti-gravity to ignite the space time fuel. Refuel the ship? Dock up to the anti-gravity bubbles called voids, stick a hose in, turn the crank, slip the card into the slot, fill up, dash off.
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    Quote Originally Posted by zinjanthropos View Post
    Quote Originally Posted by meryem View Post
    Humans tend to long for more so drive for searching newer galaxies is ever going practice...
    If you've seen one galaxy then you've seen them all, no?
    Think like the Astro community or a particular industry person thinks. For them if put to limitation than there is no scope of growth. Meaning they continuously want to grow and expand in any manner space possible. That's their way of life.

    I think it's just a matter of perception...
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    Quote Originally Posted by zinjanthropos View Post
    If going at such high rates of speed then the Twin Paradox scenario comes into play does it not? The travellers would have to consider this before they leave since it might mean saying goodbye to loved ones forever. Imagine leaving Earth with the most modern technology and returning as a museum piece. What you learned on the trip may be old news by the time you return.

    We cannot be sure people can live at such speeds. The chemical reactions that keep us alive need certain minimum energies and if time dilation does not allow this to happen, then unless people are in some form of suspended animation, they will die.

    Forty odd years ago Marvel Comics published a story about someone on a thousand year mission to the stars. A few centuries after he left, FTL travel was discovered and star ships flew past him, not wanting to wake him unless it killed him. When he finally arrived a thousand years later, it was to meet an Earth civilization set up on that planet and Earth people who greeted him. Everyone he knew was dust and everything he knew a thousand years out of date.
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    Quote Originally Posted by Cyberia View Post
    We cannot be sure people can live at such speeds. The chemical reactions that keep us alive need certain minimum energies and if time dilation does not allow this to happen, then unless people are in some form of suspended animation, they will die.
    Time dilation due to relative motion has no effect whatsoever on those "certain minimum energies", because speed is relative. You have a different speed relative to different observers, so each observer will calculate you to be time dilated by a different amount in relation to them, therefore your "energies" will also be different, depending on who you ask, and the answer will always be correct from their frame of reference.

    Of course, the person you should really ask is yourself, and time is ticking away as normal for you, at one second per second.
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    Quote Originally Posted by SpeedFreek View Post
    Quote Originally Posted by Cyberia View Post
    We cannot be sure people can live at such speeds. The chemical reactions that keep us alive need certain minimum energies and if time dilation does not allow this to happen, then unless people are in some form of suspended animation, they will die.
    Time dilation due to relative motion has no effect whatsoever on those "certain minimum energies", because speed is relative. You have a different speed relative to different observers, so each observer will calculate you to be time dilated by a different amount in relation to them, therefore your "energies" will also be different, depending on who you ask, and the answer will always be correct from their frame of reference.

    Of course, the person you should really ask is yourself, and time is ticking away as normal for you, at one second per second.
    That's a great finger photo. This forum is great! It's the first one I've been on which doesn't heap ridicule and attack. Good explanations done in understandable ways .. great stuff.
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    Quote Originally Posted by SpeedFreek View Post
    Quote Originally Posted by Cyberia View Post
    We cannot be sure people can live at such speeds. The chemical reactions that keep us alive need certain minimum energies and if time dilation does not allow this to happen, then unless people are in some form of suspended animation, they will die.
    Time dilation due to relative motion has no effect whatsoever on those "certain minimum energies", because speed is relative. You have a different speed relative to different observers, so each observer will calculate you to be time dilated by a different amount in relation to them, therefore your "energies" will also be different, depending on who you ask, and the answer will always be correct from their frame of reference.

    Of course, the person you should really ask is yourself, and time is ticking away as normal for you, at one second per second.
    Thanx speed, you got it in one, appreciate your post.
    nokton.
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    Quote Originally Posted by SpeedFreek View Post
    Quote Originally Posted by Cyberia View Post
    We cannot be sure people can live at such speeds. The chemical reactions that keep us alive need certain minimum energies and if time dilation does not allow this to happen, then unless people are in some form of suspended animation, they will die.
    Time dilation due to relative motion has no effect whatsoever on those "certain minimum energies",

    Energy as in light does not slow down so is unaffected by time dilation. While people are.
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    That's a great finger photo. This forum is great! It's the first one I've been on which doesn't heap ridicule and attack. Good explanations done in understandable ways .. great stuff.

    See any of the answers to my posts on the big bang idea.

    I could get less hatred by ridiculing Allah in a mosque.
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    Quote Originally Posted by Cyberia View Post
    That's a great finger photo. This forum is great! It's the first one I've been on which doesn't heap ridicule and attack. Good explanations done in understandable ways .. great stuff.

    See any of the answers to my posts on the big bang idea.

    I could get less hatred by ridiculing Allah in a mosque.
    I'll be disappointed if I see the hatred, I haven't seen it. And you might be surprised how tolerant Muslims are, except for the militant minority of course, but that minority exists in any sphere.
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  30. #29  
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    our thought is the fastest thing in this world. nothing is away from its reach. so nothing exits that we cant reach. everything is inside us! nothing is far away!!!!!
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    Quote Originally Posted by precious View Post
    our thought is the fastest thing in this world. nothing is away from its reach. so nothing exits that we cant reach. everything is inside us! nothing is far away!!!!!
    Yup .. I think that's how non-locality works.
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    For long trips at high speed I would be worried the ship would hit a rock or chunk of ice. When reaching speeds measured in fractions of light speed it must really hurt.


    As for going extra far, I see no point except doing it for the heck of it. But I nonetheless wish humanity will colonize other planets asap so some people can escape from the planet of the apes .
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    Quote Originally Posted by Cyberia View Post
    Quote Originally Posted by SpeedFreek View Post
    Quote Originally Posted by Cyberia View Post
    We cannot be sure people can live at such speeds. The chemical reactions that keep us alive need certain minimum energies and if time dilation does not allow this to happen, then unless people are in some form of suspended animation, they will die.
    Time dilation due to relative motion has no effect whatsoever on those "certain minimum energies",

    Energy as in light does not slow down so is unaffected by time dilation. While people are.
    Of course light is affected by time dilation!

    If someone moving relative to you flashes a light at you at one flash per second, as measured by them, then after subracting for any classical Doppler effect you will find the duration between those flashes to have been more than 1 second, from your frame of reference.

    If they were to emit a continuous beam of light, that beam would be redshifted from your frame of reference, due to time-dilation.

    Your statement is actually "not even wrong", as the speed of any object in a vacuum is not affected by time dilation! If someone is moving through space at 100,000 mph relative to you, and are thus time-dilated relative to you, how do you think that speed of 100,000 mph relative to you is even supposed to be affected by time-dilation?!

    Instead, it is their "frequency" that would be affected, from your point of view. Their clock would be "running slower" than yours, and the same would be true for light.
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    [QUOTE=Cyberia;292003]

    I could get less hatred by ridiculing Allah in a mosque.
    Haraam R US
    .
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    Quote Originally Posted by Cyberia View Post
    zinjanthropos. We do not need some kind of Star Trek technology to reach the stars. If we could build an engine which would put out one G force acceleration per second, it would take just under a year to reach almost light speed. We could then coast along for years till we have to spend nearly a year slowing down again. This would mean that we could reach a number of close stars within a decade. If time dilation works, not many years would pass for those on board depending on their cruising speed.
    There is no such unit as "one G force acceleration per second." You would need some kind of star trek technology to accelerate your ship at 1 g for any extended period of time.
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  36. #35  
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    Will it be easier to develop the necessary speed technology or discover ways to greatly extend a human lifetime? Will geneticists need to engineer a more robust and durable astronaut?
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  37. #36  
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    Quote Originally Posted by zinjanthropos View Post
    Will it be easier to develop the necessary speed technology or discover ways to greatly extend a human lifetime? Will geneticists need to engineer a more robust and durable astronaut?
    why man is so curious in nature,
    they went to moon,
    they will go out of solar system,
    they will go to nearest solar system in universe

    they will go to next galaxy

    then what, what are they finding? (i am not suggesting this is worthless effort)
    is it survival? no!! (if a deadly viru attacks all the human species can vanish within a month or a year or century)
    is it quest for power over nature?
    is it search for cure of death? (ie search for mythical eternal life)


    sir if i give you this time travel technology where will you go first? and also I give you gift of eternal life? will you not become bored?

    this is out of box reply to Zinja , friend ignore it. i wanted to give this scientific discussion a spiritual touch.

    thanx
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  38. #37  
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    Quote Originally Posted by Cyberia View Post
    If we could build an engine which would put out one G force acceleration per second, it would take just under a year to reach almost light speed.
    If I had a magic wand, I could wave it and become an instant billionaire!

    Sorry guys, but there is no way, even in theory, to create an engine that will accelerate at 1 G for one year. There is no way, even in theory, to exceed 0.2 C maximum speed. This is not my assertion. It comes from NASA scientists - real rocket science - who have done the maths.

    If we had a break through in physics, then maybe. But there is no point wishing for that. We might as well wish for the above mentioned magic wand.
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    what is teletransportation? is it solution?

    do you want to travel as light or on light (in formre way you become part of light, and in later way light becomes your carrier)

    eg
    submarine inside water
    boat on surface of water

    requirements for such travel:

    fuel type?
    destination ?
    a big push in space!

    all this looks dreamy.
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    Quote Originally Posted by Cyberia View Post
    Quote Originally Posted by SpeedFreek View Post
    Quote Originally Posted by Cyberia View Post
    We cannot be sure people can live at such speeds. The chemical reactions that keep us alive need certain minimum energies and if time dilation does not allow this to happen, then unless people are in some form of suspended animation, they will die.
    Time dilation due to relative motion has no effect whatsoever on those "certain minimum energies",

    Energy as in light does not slow down so is unaffected by time dilation. While people are.
    Permit me Cyberia, are you saying that lightspeed us unaffected when time is warped?
    Are space and time bonded together in a stable sitution to form so called spacetime,
    or do they exhibit different parameters when one or the other is distorted?
    If so, lightspeed would change relative to time distortion.
    nokton.
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    what about time swap?
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    Time to move this to trash...
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    Quote Originally Posted by Aristarchus in Exile View Post
    Quote Originally Posted by Cyberia View Post
    That's a great finger photo. This forum is great! It's the first one I've been on which doesn't heap ridicule and attack. Good explanations done in understandable ways .. great stuff.

    See any of the answers to my posts on the big bang idea.

    I could get less hatred by ridiculing Allah in a mosque.
    I'll be disappointed if I see the hatred, I haven't seen it.
    I have been insulted time after time including by a moderator, called a liar time after time, told to shut up by a moderator, etc and all because I wanted to debate the big bang.

    Most do anything but answer my posts.
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    Quote Originally Posted by precious View Post
    our thought is the fastest thing in this world. nothing is away from its reach. so nothing exits that we cant reach. everything is inside us! nothing is far away!!!!!
    Thought is just bringing up memories. The only way it could be called movement is as in electrochemical processes.
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    Quote Originally Posted by icewendigo View Post
    For long trips at high speed I would be worried the ship would hit a rock or chunk of ice. When reaching speeds measured in fractions of light speed it must really hurt.
    Yes, that would be a serious problem for speeds near light speed. You can avoid the worst though like for instance most of the material in the solar system is in a flat disk which you can fly "above or below" to avoid.

    The E E Doc Smith books written pre WWII has the characters building tear drop shaped space ships as they are subject to friction from interstellar dust and gas from travelling so fast.
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    Speedfreek. Light always moves at the speed of light.

    As to frames of reference, that is just you perceiving it as moving at different speeds.
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    Harold14370

    There is no such unit as "one G force acceleration per second." You would need some kind of star trek technology to accelerate your ship at 1 g for any extended period of time.
    Most powerful motorbikes can accelerate at more than 1G force, as in an increase of nearly 22mph per second per second (for a number of seconds).

    What we do not have is a fuel sufficient to do it for any extended amount of time since we would quickly use up any supply.

    Possibly some form of controlled nuclear fusion or fission might work though.

    Ion rockets use a similar process to build up great speeds using continuous acceleration for long periods.
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    Quote Originally Posted by zinjanthropos View Post
    Will it be easier to develop the necessary speed technology or discover ways to greatly extend a human lifetime? Will geneticists need to engineer a more robust and durable astronaut?
    Presently some are working on human hibernation, since long trips would need lots of air, food and water. However star travel with current technology is tens of thousands of years, so we need something new.

    There has been a few SF stories were astronauts have been genetically engineered for space travel, even able to survive in space without a space suit for short periods.
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    Quote Originally Posted by skeptic View Post
    Quote Originally Posted by Cyberia View Post
    If we could build an engine which would put out one G force acceleration per second, it would take just under a year to reach almost light speed.
    If I had a magic wand, I could wave it and become an instant billionaire!

    Sorry guys, but there is no way, even in theory, to create an engine that will accelerate at 1 G for one year. There is no way, even in theory, to exceed 0.2 C maximum speed. This is not my assertion. It comes from NASA scientists - real rocket science - who have done the maths.

    If we had a break through in physics, then maybe. But there is no point wishing for that. We might as well wish for the above mentioned magic wand.
    Possibly you are talking about the "ram jet" which will suck up interstellar hydrogen as fuel once it reaches sufficient speed, which is believed to have a limiting speed of maybe 0.2C?

    Strictly speaking if you can keep pushing out some form of thrust for long enough, the light barrier is the only limit to your speed.
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  50. #49  
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    nokton
    Permit me Cyberia, are you saying that lightspeed us unaffected when time is warped?
    Are space and time bonded together in a stable sitution to form so called spacetime,
    or do they exhibit different parameters when one or the other is distorted?
    If so, lightspeed would change relative to time distortion.
    nokton.
    Timespace came from mathematicians. When they are working out travelling through space on a bit of paper or a computer, they take time into account, with many points between A and B.

    They then confuse their maths with the real world and start talking of space as though it were time also, and that a rocket ship would not get you to the Moon because you'd need a Tardis to travel through time and space.

    You can talk of time dilation but that is not relative to space but to the speed you are travelling at.

    It just confuses things so easier to talk of space alone.
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  51. #50  
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    Quote Originally Posted by Cyberia View Post
    Speedfreek. Light always moves at the speed of light.

    As to frames of reference, that is just you perceiving it as moving at different speeds.
    I was replying to your assertion:

    light does not slow down so is unaffected by time dilation. While people are.
    Your statement is not even wrong, in the context of time-dilation (which is what you were addressing). You are mixing up a speed through space (the speed of light) with a speed through time (people are affected by time-dilation).

    The speed of light is unaffected by time dilation as you say, but likewise, the speed of an orbiting GPS satellite is also unaffected. The speed of a person through space is not affected either. Time-dilation does not change the speed of an object, relative to the observer.

    What is affected by time-dilation is the duration of an event, or the duration between events. If a light pulse is emitted at regular intervals from a source in motion in relation to you, you detect those pulses and after calculating out the Doppler effect you will find the pulses to have been further apart, from your frame of reference, than they were in the frame they were emitted. The same will be true for the pulse rate of a human in the frame of the source, or the oscillations of a quartz crystal in the frame of the source. Time at the source is dilated, relative to your frame of reference.
    Last edited by SpeedFreek; November 14th, 2011 at 06:40 PM. Reason: changed "from" to "relative to"
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