Einstein says, nothing can cross the speed of light. So he relates it with time and if anything going near light speed it starts to travel in time and it'll decrease. For nearer light speeds time is decreasing and in the light speed time will stop. So light moving in its own speed thats light speed. So why it's taking 8 minutes for it to reach from Sun. It should be zero???

Question

stormfire1 · Answer

The difference here is the reference frame.  If you were on a ship travelling the speed of light time would theoretically stop in your reference frame.  However, if you're on the Earth you're in a different reference frame which is why it takes 8 minutes for the light to reach you.

anonymous · Answer

For light it is in its reference frame. Then?

stormfire1 · Answer

The reference frame is the point at which the measurements are taken (or where the observer is).  If you're travelling with the light (at light speed) then your reference frame is the same as the light's and time will stop for both you and the light.  On the other hand, if you are observing the light from another reference frame (point), then the light will take time to reach you.

I hope that makes it a bit more clear...it's a wierd concept to grasp.

stormfire1 · Answer

Another way to think about reference frames would be to consider a high speed train.  If you're on the train then you are in the same reference frame as the train.  The train does not appear to be moving relative to you because you're both moving at the same speed.  If you're at the station watching the train, the train appears to be going very fast...RELATIVE to you (and your reference frame).

anonymous · Answer

Dude i know well about reference frame. I'm asking if cosmic rays coming to ground level due time dilation then wahts the actual nature of light.

stormfire1 · Answer

The help here is free so take it or leave it. You originally asked: "So why it's taking 8 minutes for it to reach from Sun. It should be zero???" If you understood reference frames (and time dilation) you'd know why it takes 8 minutes for you to see light from the Sun yet for the light itself time is stopped. Maybe these videos will help with this question as well as your black hole question: http://www.youtube.com/user/ScienceTV

anonymous · Answer

Sorry if it hurts. I'll check the video abd come back.