January 21, 2007

Back to the Future

a plane breaking the sound barrierIs it really possible to go back in time? Well, that's a question where even established scientists would differ in their opinions. What would it be like breaking the speed of light? I don't know. No one knows. But we do know what it is like breaking the sound barrier.

Imagine a supersonic jet lying stationary on a runway (taxiway) making a horrendous noise of its whirring engines. The sound waves
around the plane travel at the speed of sound and thus go away from the plane. Now as the plane moves, the plane narrows down the distance between it and the sound waves that lie in front of it. When the plane is traveling at the speed of sound, then it can hear the sound that's being produced in real time, as well as all the sounds it produced in the past, as it is now flying at sound's speed. (We presume here that the 'past' sound is still audible and it is flying in a medium where sound can travel,among other things). What a horrible Frankenstein of a creation! We hear more sounds, in addition to the present one. This is the sonic boom.

Lets gather more speed now. Now we leave those awful noise behind. We leave history (of past sound) behind, which we can re-live. Should we stop the engine now (in God we trust), we could hear the sounds that the plane made in the past: (as those sounds were behind us when we were flying at more than sound's speed), as they now travel ahead of us.

How about this scenario? Imagine a little boy lighting a firecracker. You can see the smile on his face as the firecracker explodes in a multitude of colors. Wait, didn't you hear the sound much later? Yeah, and that's because light travels the fastest, while sound's speed is much slower, in comparison. If you were to fly away from the scene by a concorde jet, at the speed of sound, you could hear the firecracker's sound forever. If you flew at more than the speed of light, you would have left that event far behind, so far that I could see it again when you stopped. Aren't we relieving the past, or going back to the past for that matter? That's precisely why physicists (and of course, the traffic police) are unwilling to let you fly at that breakneck speed for you will end-up in another universe (the other side of light).

The above is a simple way of trying to explain such a tough poser, which honestly I don't understand. It is not exhaustive by any means and reflects my views only. Help me enrich myself with your own views in the form of valuable comments, suggestions or corrections.

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