06 Apr '08 04:16>
We all know about time dilation as you get closer and closer to C.
for instance, at 0.9C, the dilation is about 2.3:1. But at 0.1C the time dilation is only about 1:1.0101, a shortening of the journey by about 1 percent. So really this time dilation thing has two parts. One part is the actual velocity, and the other the time dilation ratio.
So at 0.9C, using 186,282 MPS as C, then 0.9C is 167653.8 MPS
Consider the distance to Alpha Centauri, the closest known star, at least one of the triple anyway at 4.3 odd LY. If time dilation were not a factor, if you went at C, it would take you 4.3 years, and of course if you were going at C, people on earth would still think it took you 4.3 years but it would be near instantaneous. Impossible of course.
But look at lower numbers.
If you go 0.1 C, ignoring time dilation, it would take 43 years to get to AC.
With time dilation taken into account, your time is about 1 percent less, or about 42.57 years. On board the craft, you know time went by a bit faster and you shaved 6 months off your journey, but you know it was not even close to the speed of light so you turn around and go back home, you have aged one year less, but your clocks are only out by that much. So you get closer to C. Suppose you go 0.5 C.
93,141 MPS. Time dilation now makes your clocks run about 15 percent faster, but you are still going only 0.5C. so now that same journey not counting time dilation, takes 8.6 years, but you think its 15% faster or about 7.3 years. Not quite up to light speed yet.
But you notice, at some point you getting closer to C, there is a velocity you travel that has you going at the speed of light, that is to say, it takes 4.3 years according to your clock so you THINK you are going at the speed of light but sadly, you get home and somewhat more time has elaped on Earth. What is that velocity? If you go at 0.9 C, the journey would take 1.1111 times 4.3 years or about 4.77 years
but the time dilation ratio at that velocity is about 2.3:1, so your clock says it took 2.07 years so you think you went over TWICE the speed of light. Of couse earth clocks disagree, but what is the velocity where you think you went exactly at C?
for instance, at 0.9C, the dilation is about 2.3:1. But at 0.1C the time dilation is only about 1:1.0101, a shortening of the journey by about 1 percent. So really this time dilation thing has two parts. One part is the actual velocity, and the other the time dilation ratio.
So at 0.9C, using 186,282 MPS as C, then 0.9C is 167653.8 MPS
Consider the distance to Alpha Centauri, the closest known star, at least one of the triple anyway at 4.3 odd LY. If time dilation were not a factor, if you went at C, it would take you 4.3 years, and of course if you were going at C, people on earth would still think it took you 4.3 years but it would be near instantaneous. Impossible of course.
But look at lower numbers.
If you go 0.1 C, ignoring time dilation, it would take 43 years to get to AC.
With time dilation taken into account, your time is about 1 percent less, or about 42.57 years. On board the craft, you know time went by a bit faster and you shaved 6 months off your journey, but you know it was not even close to the speed of light so you turn around and go back home, you have aged one year less, but your clocks are only out by that much. So you get closer to C. Suppose you go 0.5 C.
93,141 MPS. Time dilation now makes your clocks run about 15 percent faster, but you are still going only 0.5C. so now that same journey not counting time dilation, takes 8.6 years, but you think its 15% faster or about 7.3 years. Not quite up to light speed yet.
But you notice, at some point you getting closer to C, there is a velocity you travel that has you going at the speed of light, that is to say, it takes 4.3 years according to your clock so you THINK you are going at the speed of light but sadly, you get home and somewhat more time has elaped on Earth. What is that velocity? If you go at 0.9 C, the journey would take 1.1111 times 4.3 years or about 4.77 years
but the time dilation ratio at that velocity is about 2.3:1, so your clock says it took 2.07 years so you think you went over TWICE the speed of light. Of couse earth clocks disagree, but what is the velocity where you think you went exactly at C?