The story of the universe is written in the light that travels through it - the light that we can capture, that is. Nearly everything we know about how the universe works on its grandest scale comes from the analysis of light, of photons that may have journeyed for nearly fourteen billion years to reach us from the Big Bang itself. In 'Five Photons,' astrophysicist James Geach serves as our guide on this cosmic voyage. Have you ever wondered what the most distant source of light we can see is, or how a star shines? Did you know that black holes can blaze like cosmic beacons across intergalactic space, and that ancient radio waves might herald the ignition of the very first stars? Have you ever thought about what light really is? Geach explains all through five tales of fascinating astrophysical processes that propel light across space and time.