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I can't really seem to understand this............
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by
on 2010-12-22 20:00:11 (edited 2010-12-22 20:01:02)
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Excuse me, gentlemen and ladies. One thing, that I'd really like to understand is how on earth is it even possible that if one were to travel at the speed of light that in such a way as to be able to somehow, 'AGE' an object. In other words, how does travelling at the speed of light be able to age an object several years ahead, while still allowing other objects to remain at roughly the same age? My friend tried to explain it, but as always, he explains things a little bit fast and 'all-over' the place. Sorry for interrupting but I just can't seem to get my mind set on this. Anyone care to help? I'll be glad that there are at least some people out there willing to make things easier for me........... :P  |
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Re: I can't really seem to understand this............
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by
on 2010-12-22 20:19:39 |
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1. Massive objects (objects containing non-zero rest mass) can not travel at (or beyond) the speed of light. http://en.wikipedia.org/wiki/Speed_of_light 2. You are asking about the Twin Paradox: http://en.wikipedia.org/wiki/Twin_paradox The difference in the ages of the twins once reunited is due to relativistic time dilation. Put simply, "moving clocks run slow". 
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Re: I can't really seem to understand this............
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by Koishuujin
on 2011-01-01 19:22:42
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It's because according to the special theory of relativity by albert einstein, there is no such thing as absolute time... There is such a thing called time dilation in relativistic physics... That means that the "clock" of a faster object tends to tick slower, and... The "clock" of a slower object tends to tick faster... That is, relative to each other... It means that there is no such thing as a universal clock, and time is therefore not absolute... This phenomenon cannot be observed in everyday situations because... The faster object at least have to be 80% as fast as light to bring out noticeable results, which is virtually impossible in today's technology as light travels 300,000km in just a second, can you imagine that? |
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Re: I can't really seem to understand this............
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by
on 2011-01-22 22:55:33 (edited 2011-01-23 14:31:09)
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Koishuujin, you're right. Objects that travel faster age more slowly than slower objects. Nishizawa, I think you worded your question wrong. Traveling at the speed of light would actually cause an object, say an animate object like a tortoise, to cease to age as long as that speed is maintained throughout the whole journey. In 200 years, a twin of the tortoise on Earth would age 200 years and be dead. This is because for the turtle traveling at the speed of light, the length of the journey only took an instant, while for the turtle on Earth, the length of time of the other turtle's journey is 200 years relative to the Earth. According to Einstein, both light and time are absolute and relative, but never universal. If this sounds contradictory, this is where i got it from: http://home.pacbell.net/skeptica/time.html. You should also read this article in Wikipedia on time dilation: http://en.wikipedia.org/wiki/Time_dilation. According to the article, time dilation comes from the relative velocity of motion between two observers, or the difference in their distance from a gravitational mass. Time dilation happens even at everyday speeds, but the difference in relative times is so small that it's negligible. I think scientists have used rockets to test time dilation, and I think there was a tiny difference in the passing of time for a clock in the rocket and a clock on Earth, perhaps only a few milliseconds. It's only at speeds somewhat close to the speed of light that time dilation becomes far more apparent. The same can be said about the effects of gravity on time dilation. Objects with huge gravity, such as black holes, can cause significant time dilation. In fact, black holes are the prime example. If two identical clocks were pulled towards a black hole, for the closer one, time would pass more slowly, and for the farther one, time would pass more quickly. (It's a pity Einstein isn't still around. Obviously, the best person to answer your question would have been him. But the next best thing is to read his work on special relativity and general relativity.) By the way, your question can only be purely theoretical because as Gendou said, objects with nonzero rest mass cannot reach the speed of light. To an observer, as an electron's speed approaches the speed of light, it's relative mass increases, making it more and more difficult to accelerate it from the observer's frame of reference. According to Delta V from http://answers.yahoo.com/question/index?qid=20081101150052AAcZCBt, "At 99.99999...% the speed of light the object will have a mass *near* infinity so you'll need nearly infinite energy to accelerate. To get the object to light speed you'd need *infinite* energy, meaning all of the energy in the universe." Basically, getting an object with nonzero rest mass to light speed is against the laws of physics. According to Einstein's special theory of relativity, it's impossible.  |