Light that took its time

Light that took its time

What we see in the night sky isn’t what’s there. It’s what was there—long ago, and sometimes, long gone. Light takes its time. Even the fastest thing in the known universe arrives late. When you look up at Sirius, you’re seeing light that left during the last federal election. When you spot Betelgeuse, the photons hitting your eye began their journey when the Han dynasty still stood. And when you marvel at galaxies in deep field images, you’re l…