Welcome back, Spherical Cow Moonions! This week we are continuing our journey through the history of the universe and discussing Cosmic Dawn. We will be talking about what Cosmic Dawn is, the properties and formation of the first stars and why they are so interesting! Please see some additions/amendments to our discussion below: 04:45 - To explain this a little further, ATLAS is one of the four detectors located around the Large Hadron Collider ring at CERN. Two protons beams, travelling in opposite directions, collide inside the ATLAS detector. Before this collision, the momentum in a direction perpendicular to the proton beams is 0. Therefore, after the collision, the momentum in a direction perpendicular to the proton beams must also be 0 since momentum is always conserved in collisions. So, if ATLAS detects any particles travelling in a direction perpendicular to the original proton beams there must be other invisible particles (possibly dark matter) travelling in a different direction so that overall the momentum in a direction perpendicular to the original proton beams adds up to 0. 12:32 - Just to clarify, these Population II stars are not just found in the Milky Way but all over the universe! They are often found in 'globular clusters' (spherical groups of stars found within many galaxies). The age of these stars is similar to the age of the Milky Way so Population II stars were formed around 13.6 billion years ago. To view our sources please see our website - https://www.podpage.com/spherical-cow/ N.B. This episode was recorded virtually so the audio quality might be different to normal.