Undeniable by Bill Nye Read Free Book Online Page A

the uniquely British sobriquet of Lord Kelvin) provided the science world with a seemingly authoritative calculation that Earth was between 20 million and 400 million years old, tops. Evolution seemed to require ten or a hundred times as much history. It was a paradox. The true age of Earth remained a mystery through Wallace’s and Darwin’s lives. It wasn’t until the discovery of radioactivity that scientists grasped the answer. Kelvin had assumed that Earth had been cooling ever since its birth, and he used its present temperature to deduce its age. What he didn’t know is that radioactive elements deep inside our planet keep adding new heat. His calculations were perfect, but his understanding was not. In fact, there was plenty of time for evolution to unfold—every bit as much as Darwin imagined, and then some.

    I often reflect on what an extraordinary time (pun intended) it is to be alive here in the beginning of the twenty-first century. It took life billions of years to get to this point. It took humans thousands of years to piece together a meaningful understanding of our cosmos, our planet, and ourselves. Think how fortunate we are to know this much. But think also of all that’s yet to be discovered. Here’s hoping the deep answers to the deep questions—from the nature of consciousness to the origin of life—will be found in not too much more time.

 
    6
    ON THE ORIGIN OF EVOLUTION
    While my family was seated together eating a chicken dinner, sometime back in the 1960s, my father described a scene around his family’s table that I like to think of as his version of Darwin’s trip to the Galapagos: the moment when he realized that all living things are related. My grandparents lived in a pretty big house in Washington, D.C. To supplement their income during the Great Depression, my grandmother rented rooms to young men, students, or people just starting out in their careers. One of these guys would often sit at the dinner table and remark offhandedly about the close similarities between a chicken’s knees and our knees, along with other unsettling anatomical parallels.
    According to legend, my grandmother was okay with these observations, and her approval carried with it an acceptance of evolution and natural selection. She was quite the naturalist and spent a great deal of time studying wildflowers. But my grandfather, who attended church regularly, was troubled by all this. A link between humans and chickens flew in the face (or beak) of his churchgoing upbringing. The tenant was very nice and paid his rent on time, but his chicken talk was not-so-subtly influencing the kids—my father, his brother, and their friends. These dinners gave my father food for thought for the rest of his life.
    My dad returned from World War II and went to work as a salesman. Nevertheless, he often referred to himself as Ned Nye, Boy Scientist. My mom spent that war as a lieutenant in the Navy. She was recruited because she was good at math and science; she went on to earn a doctorate in education. So I was brought up with a great deal of respect for the human capacity to figure things out and solve problems. As a kid growing up in Washington, I also had access to the Smithsonian Institution. I was often dumped off … er, I mean, I was often given a ride to the downtown bus and encouraged to visit the museums and see the sights. Like any kid, I was utterly fascinated by the ancient dinosaurs. I thought about how cool it would be to see one of those animals in the wild. Evolution was in my bones, you might say. I was immersed in the scientific story of life on Earth pretty much from the time my own life began. It’s no wonder I ended up writing this book.
    Now consider what things were like when Charles Darwin and Alfred Wallace were formulating their ideas in the first half of the nineteenth century. They lived at a time when few people considered the biological meaning