DeadWrong's Blog

We experience time at a ratio of 1:1. No matter what we do, or where we go, how fast we travel, your wristwatch will still count 60 seconds to the minute, 60 minutes to the hour, 60 hours to the day^H^H^H... you get my point.

The differences in time travel are relative. The faster I go, the more time slows down outside my experience. My previous posting, I talk about my spaceship and traveling from New York to L.A. in .00000000001 second.

What would happen if I were traveling at 99.999% the speed of light, then I turned on my headlights? (The answer is printed below, you may have to turn your monitor upside down to read it)

Answer: If you were cruising at 99.999% the speed of light, and you turned on your headlights - your headlights will shine bright ahead of you and will project a beam, at the speed of light.

How? To the outside (stationary) observer, you are traveling at, or near, the speed of light. If they watched you turn your headlights on, and saw that the beam slowly outpaced your movement. However, remember that there is a time-shift happening based upon relativity and observation. For each observer, time is progressing at a 1:1 ratio. From my perspective, time marches on at its normal pace, headlights come on, and even though the beams are advancing out in front of me at .001% faster than the speed I am traveling, time has slowed to 99.999% of its original speed. So for me, the observer in the spacecraft, the light will shine brightly ahead of me illuminating my path before me.

Light speed and Time Travel
Now, lets say that we have shined the light through water, or some medium which slows the speed of light, and using my spacecraft I arrive before the beam of light does... so what. Have I just traveled back in time?

Uh, no. Sorry. You cannot travel a distance so fast that the rate of change becomes time itself. You have just pulled off a magic trick, of sorts, but time travel into the past is not possible - even for God.