> For 2.5 million years, those photons were freely zooming through space [...] Imagine the faces of Penzias and Wilson when they learned that the noise in thei

> For 2.5 million years, those photons were freely zooming through space [...] Imagine the faces of Penzias and Wilson when they learned that the noise in their horn antenna wasn't bird poop but photons traveling 14 billion years without interacting. See Cosmic Microwave Background.