By the Book 5

Ok...so you know you are old when you write out an entire post and forgot to post it, so here's yesterday's post.

Before this ‘decoupling epoch’ or plasma period comes the ‘epoch of equal densities’ (I’ll have to make up my own spiffy name). So I think the all the ‘epoch of equal densities’ denotes is when the shift from radiation dominance to matter dominance occurred…yeah I think that’s it…but I could be wrong.

Before this was…obviously the radiation dominance era. This ere began when the universe was only a second old and lasted for about 100,000 years. Harrison takes a moment to talk about what it must have been like to be there in person, and I had never thought about that before. You would be trapped in a super hot fog of light. You would be surrounded by extremely intense white light (among all the other wave lengths). That would be pretty cool.

Shortly after the radiation era begins free protons and neutrons clump together to form helium nuclei. There were already a lot of hydrogen nuclei (protons) and a bunch of free neutrons and when the temperature got just right…they came together like the detonation of a giant hydrogen bomb all over the universe! But can you believe it… the temperature of the universe was already so high that the fusion of all that hydrogen into helium didn’t raise that temperature that much. Crazy stuff.