When we gaze at a star in the Milky Way which is 50,000 light-years away from our sun, we are looking back 50,000 years in time." "The idea is much too big for my little head." "The only way we can look out into space, then, is to look back in time. We can never know what the universe is like now. We only know what it was like then. When we look up at a star that is thousands of light-years away, we are really traveling thousands of years back in the history of space.