There is an introduction to the nature of the “Hubble tension” in the first part of this article, which covers measurements based on the distance ladder (see https://physbang.com/2026/07/28/hubble-tension-part-1-the-distance-ladder/). This article looks at how the Cosmic Microwave Background (CMB) can be used to calculate the expansion of the Universe – and therefore the Hubble constant. But … Continue reading Hubble Tension Part 2: Baryon Acoustic Oscillations
Why believe in the Big Bang?
It is often said that the reason why we “know” the Big Bang took place is because the Universe is expanding and if time were played backwards then everything would have started from the same point at the same moment in time. That moment, when everything started moving apart, is what we call the Big … Continue reading Why believe in the Big Bang?
