The universe might be infinitely large. And even if it’s not, it’s probably so big that it might as well be infinite. But we see only a tiny fraction of that extent — a bubble known as the observable universe. What we see is limited by the speed of light — 670 million miles per hour. That’s fast. But it’s not infinite. So light can travel only so far in a year, or a century, or a billion years. Because the universe was born 13.8 billion years ago, we can’t see any farther than light can travel in that time — 13.8 billion light-years. The farthest galaxies and quasars that we’ve seen are almost that far away. Or they were that far away. We see these objects as they looked at a distance of more than 13 billion light-years. But keep in mind that the universe is expanding. So today, there’s a lot more space between us and those early objects. In fact, today the edge of the observable universe is about 46 billion light-years away. Assuming Earth were still around, in tens of billions of yea
