Ask Ethan: Could the CMB arise from galaxies, not the Big Bang?

Ask Ethan: Could the CMB arise from galaxies, not the Big Bang?

Every once in a while, an idea comes along that turns our conventional understanding of the Universe on its head. We have our current understanding of the Universe: the laws that govern reality, the conditions and properties of the physical Universe, and the initial conditions that gave rise to the cosmos we observe today. But sometimes, surprises fall into our lap, and they cause us to re-evaluate everything we think we know. However, new infor…