Chapter 4

Summary:
          Chapter 4 is where writer, Sam Kean, begins explaining life and how the world became what it is today. He starts off simple with an ideology that everyone has heard of: The Big Bang Theory. He states a mind boggling fact, "They're neither created nor destroyed, elements just are. " This quote begins to make us, the readers, think more about the elements and their placement in the world. He goes on informing on the planets and how the same elements here can have different properties on another planet. He explains the irony of the element uranium being named after the discovery of the planet Uranus because there is zero percent of uranium on Uranus.
          Continuing to elaborate on planets, Kean decides to go into depth upon the planets Jupiter and the properties of elements on this gas giant. Jupiter was said to be a star that never made it, but if it were it would be a dwarf star and emit brown light. When the big bang blew, only the most basic elements reached to lengths as far as Neptune. He explains further that the gas giant's most common elements are 90% hydrogen and 10% helium. Kean later brings up the age of the earth which scientist, Clair Patterson, most closely estimated to 4.55 Billion years. He calculated this number by studying "star dust" on meteors and comets that came from the same dust as planet earth.
          Moving forward, Kean begins to talk about a father-son duo: Luis and Walter Alvarez. This pair of physicist- geologists found that there was a layer of dust and clay which is in perfect alignment to explain the death of the dinosaurs. Iridium was found in the clay, iridium can only come from asteroids or comets. In the end the pair ended up hypothesizing that the earth seemed to have many of these layers of clay. They thought that there were maybe a huge celestial being but then they would've spotted it by now. They concluded that the earth would over go mass extinction every so often.

Reflection:
          This chapter was full of interesting facts that opened my mind to the universe. I disliked the fact that this chapter did not go into so much depth with the Big Bang Theory. I learned many new things, but a memorable fact was that elements were never made nor can they be destroyed. On a night out with bae, I would bring up the fact that the history of the world is unknown so I can bring in a cheesy pun such as "just like the infinite love I have for you."