3 ms·

I don't understand how it could be less than 39 years for the traveler. Time dilation is a thing, but being less than 39 years would mean the traveler observed

• simias 10y ago
  That's correct. You wouldn't be able to do the roundrip expedition in less than 78 years from an observer's standpoint so you still can't transmit information faster than the speed of light, however from the explorer's point of view it might take a lot less time to do that as you get closer to c. If you travel at the speed of light (assuming you're a photon or something) then time stops "existing" altogether and you are simultaneously at the point of origin, destination and everywhere in between. At least that's my understanding of it. I find it both exciting and depressing at the same time, it means that you could potentially make a rountrip to the center of the milky way and back within a human lifetime but by the time you'll be back everybody that remained on earth would be long dead and nothing would be the same anymore. If those types of travels become common then society would stop existing on a single timeframe. It's pretty mind boggling.