Question: What's your favourite fact about The Big Bang?

Mark Jackson answered on 15 Mar 2014:

That it had an echo called the Cosmic Microwave Background. I think that most people, even scientists would have a difficult time believing that the Universe had a beginning. We suspect it from the fact that the Universe is expanding, but there are possible explanations for this. For the Universe to have this background radiation is hard to imagine except if it were once hot enough for atoms to dissolve into elementary particles, absorbing the radiation. Not only is the general idea correct, but even the precise calculations of the observed wavelength are exactly what we predicted from the Big Bang theory. I could say it’s “like” having a snapshot of the Big Bang, but we now quite literally have a picture of the Big Bang thanks to very precise instruments such as the Planck satellite: http://goo.gl/lwp1nh.