What we see is limited by the speed of light – 670 million miles per hour. This is fast. But it is not infinite. So light can only travel so far in a year, a century, or a billion years. Because the universe was born 13.8 billion years ago, we can’t see farther than light can travel in that space — 13.8 billion light years. The most distant galaxies and quasars we’ve seen are almost that far away. Or was it that far. We see these objects as they look more than 13 billion light-years away. But keep in mind that the universe is expanding. So today, there is much more space between us and these early objects. In fact, today the edge of the observable universe is about 46 billion light years away. Assuming the Earth was still around us, in tens of billions of years, we would see what these objects look like today. And the limits of the observable universe may eventually reach about 60 billion light years. But the universe is expanding so fast that we would never be able to see farther—confining us to a bubble of space and time in a possibly infinite universe. We’ll have more on the observable universe tomorrow. Screenplay: Damond Benningfield
