Chapter 4

Chapter 4 

Summary- Kean initiates the chapter by posing a question on where the elements come from. He references the big bang theory of the 1930's, which stated that every element was released by said event. This was disproven by the fact that the theory implies that the elements would have been evenly distributed everywhere, but hydrogen and helium are concentrated primarily in stars because they burn by fusing hydrogen into helium. The fusion of hydrogen and helium would create elements further along the periodic table. However, iron is the final element formed. This occurs because fusing anything beyond iron costs the star energy, which will eventually bring an end to the star's life. Supernovae cause the burst in energy that can cause iron to fuse into other elements beyond number twenty-six.
      Kean later talks about Jupiter and its peculiar chemical makeup. He refers to it as a "'tweener", or a failed star. He states that Jupiter could have been a brown dwarf star. He moves onto the terrestrial, specifically touching upon the age of Earth. Clair Patterson makes the best estimation of the planet's age, estimating that it is about 4.55 billion years old through the use of lead and uranium from meteors. Kean also explains the origin of the atomic symbol for lead, Pb, because lead has often been used for water pipes, so Pb is derived from the Latin word for plumber. He presents a theory of a binary solar system, calling the second "sun" Nemesis. It could serve to explain the suspicious time frame between mass extinction events, but it seems less and less likely with every year providing no evidence to support its existence.
      I liked that Kean again let the chapter flow from story to story very smoothly. He also keeps the stories constantly interesting with facts, such as the cult suicide because of the Hale-Bopp comet. I also like that he provides a very realistic opinion on whether or not the Nemesis theory is plausible. I did not like the lack of spoons, specifically a disappearing one. Maybe that's why there isn't a spoon, it has already disappeared from the reading.
      I learned that anything beyond iron is not formed in living stars, but rather in stars that die, implode and then explode. I also learned that it is highly likely that everything inside of human beings is quite literally made from the cores of stars. If I had a bae to tell something to, I'd tell them that even though some theories seem great, without any tangible evidence, that's all they'll ever be: theories.