The idea of rocket travelling faster than light and going into the past, means we could very well send a nuclear warhead anywhere, at anytime into the pass. That sound dangerous...

Anyway, you can't reason speed of light without considering the effect of space-time continuum. If 2 person, one of them (person A) travel to Mars. With existing technology, he'll reach there in 18 months (June 2011). Then the other person (person B), travel at speed of light for 18 months, going many places and finally stop at Mars on June 2011. When these 2 person meet, both of them aged 18 months, neither is younger nor older. The reason because they arrive at the same space, on the same time we specified.

Next, person C, travel to Mars at speed of light in 4 minutes. Along the way, he look back at earth, to him, time has stopped on earth. As soon as he arrive at Mars, he took out a telescope and look at earth. He will discover that the earth look exactly the same as he left. Physically, he aged 4 mins. But at mars, in earth-time, he has not aged. A friend on earth, look through telescope, will see that, as if, he teleport to Mars instantly and has not aged at all.

Then he travel back to earth at light speed, took him 4 minutes. Similarly, he look at earth along the journey, and find that time pass twice as fast. Back on earth, physically he aged 4 minutes, but in earth time, he aged 8 minutes.

Aging still applied to the lightspeed traveler, only on relative s

On earth, despite if we travel at light speed, it makes no different and we will aged the same. Because earth locate on a very specific (and small) space-time continuum. Travelling beyond speed of light will only make us arrive at our location faster, still, neither are we going to be younger or neither can we go back in time. That is on earth scale.

Yeah. And your source of unlimited knowledge is wrong. Time do exist.

FYI, a hypothesis is classified as untrue when it is proven wrong, not the other way round. If time don't exist, how else did you grow old?

How does genetic evolve? How does our body cell regrow? Evolution happen because time exist. It's like proving gravity. We say gravity exist because stuff fall onto ground. If time don't exist, stuff won't even fall. The sequence of event from day to day is the result of time.

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Added on December 21, 2009, 12:37 amWell, I'm just giving a suggestion to your hypothesis, "time does not exist". In order to make your hypothesis true, you need to prove that time does not exist. I'm not judging your unlimited limited knowledge whatsoever.

This post has been edited by Aurora: Dec 21 2009, 12:37 AM

Imagine an ant on a flat surface. As it crawl on the surface, that is the absolute speed of the ant on the flat surface. Time, is like the 3rd dimension to the flat surface. When we say speed of light appear constant to all observer, disregard if the observer is moving or stationary; it's like saying an ant observing a ray of light shining in the 3rd dimension across the flat surface.

Light, in the 3rd dimension, will always appear constant to the ant, be it that the ants are moving or not. However, if the ant is moving at near LS, by normal physic, the speed of light in the 3rd dimension should have change.

When relativity theory say that light will always be constant, the last statement is not possible (where light speed have change). Rather than the light speed is changed, time slowed down.

In our 3 dimensional world, light pass through our 3-D world, slicing through the time-dimension. Which is why light speed will always be constant relative to us, no matter where and how fast we travel.

As we travel faster, still within our 3-D world, we need to obey the "light speed is constant". If not we will catch up with light speed (aka the scenario describe by jswong). The only way for light speed to remain constant, is to slow down the time around the traveler. At least that is how I reason it.

The ultimate question is, does the traveler action automatically slow down as well too? Or his action is still at normal speed but only the time slow down?

If the answer to the first one is true, then he will observe that light is travelling faster than lightspeed. If the answer to the second question is true, then he would probably aged the same as his twins on earth.

Human consciousness of time flow with time, so is our regenerative capability. if time stop, then it means everything stop. we wont notice if time stop at all, because our brain stop when time stop.