I don’t really understand it, could someone explain in basic terms?
Are we saying if a star is 120 million lightyears away, light from the star would take 120 million years to reach us? Meaning from the pov of time on earth, the light left the star when the earth was still in its Cretaceous period?
In: 292
Put a rope or string on the ground. Now wiggle it back and forth. It makes a wave, and it takes some amount of time to get to the other end.
Sound works the same way. Go into a canyon or alley between two large buildings and yell. It takes some amount of time for the echo to reflect back. Just like if you were in a swimming pool and made a wave, it would take some amount of time for the wave to hit the edge of the pool and come back.
Light also works in waves, bit it is much much faster. But things in space are really far apart.
A light year is the amount of SPACE that light can travel in one year. If you stand one light year away and shine a really bright light at the earth it would take one year to reach us, just like the string you wiggle on the floor takes some amount of time for the crest of the wave to hit the other end. If you did this today, people of Earth would see it on Feb. 10, 2023.
Latest Answers