# How can light reach us from 14 billion light years away?

One thing that I can't quite wrap my head around is how light is traveling to Earth from 14 billion light years away, aka the beginning of the universe.

The way I see it, the universe itself was very small 14 billion years ago and has been steadily accelerating in size since. So the photons that left a star that existed 14 billion years ago couldn't travel for 14 billion years because the universe itself was probably only a few million light years total in diameter. The universe is not expanding faster than the speed of light, so that photon should have hit the end of the universe before now.

What piece of this puzzle am I missing?

• A comment to the general public: Why have there been so many expansion-of-the-universe-related questions recently? – HDE 226868 Sep 18 '14 at 22:52
• Doesn't astronomy=study of the universe? – Scottie Sep 18 '14 at 22:53
• I'm not saying your question doesn't fit here; it fits fine. I'm just surprised at the frequency of the questions related to the expansion of the universe because so many other topics are in scope. Astronomy is the study of the universe on a large scale and many objects in it - stars, galaxies, black holes. It just seemed odd to find so many questions asked recently related to the expansion of the universe. But your question fits here fine. – HDE 226868 Sep 18 '14 at 22:55
• @Scottie - No. The study of the universe is cosmology. Astronomy is the study of the life of stars, which is a much smaller field. Astronomy doesn't include the Big Bang, the CMB or the formation of early galaxies, for instance. – stevenvh Sep 19 '14 at 11:05
• Regardless, the question is definitely on-topic. But astronomy does include the study of galaxies and other celestial objects. – HDE 226868 Sep 20 '14 at 20:20

• That's a hypothetical number you're using as an example. The expansion occurs at escape velocity, and that's lower than $c$. The explanation comes from the inflation epoch. – stevenvh Sep 19 '14 at 11:08