As a person moves faster, time is relative and slows down, but i was wondering if that was only for time around the person? As a person would near the speed of light, and time slow down around them, would time slow down in them? Would they themselves slow down, or would their body continue working at the same speed it always did?

The person moving would not notice anything different. They would experience time just as you and I do here on Earth. So, too, would their internal organs and cells.

 

When people discuss the slowing of time when an object approaches the speed of light, that slowness is relative to someone else.

 

So, you are traveling near the speed of light, but you would not experience any slowness... everything would appear perfectly normal, and your internal body parts would not be changed.

 

However, me... I'm still back on earth, and I'm measuring your time. From MY measure, your time is slow... I get older and older, all while barely any time has passed for you. Eventually, I die and you are still quite young.

 

It's only relative to other reference frames that it makes sense to talk about slowing or speeding of time. In your own reference frame, you don't notice any changes.

 

For this reason, the question, "would their body continue working at the same speed as it always did?" ... really doesn't make much sense, because you have to include a key variable in your question... relative to whom/what?

thanks! i think i figured it out though. Lets say i was moving close to the speed of light (not taking into account the whole mass change thing), then to me, everything would seem to slow down, and therefore, i would actually slow down. The faster you move, the slower your external and internal clock, which is why i would still be younger then a person watching me. My whole body wouldnt be moving at the same time it was when i wasnt moving, but would be working much slower, which is why einstein found that if he rode on a light beam, he would only see a still picture of a photon (i think it photons right?) of light. Thanks! (at least i think thats right)