Did you ever wonder how somebody ever figured out all the details of making a cellphone system work? What about those giant MRI machines that can take a picture of your insides without a single incision? Then there is the universe. We think we know at least something about how it started billions of years ago and where it’s going billions of years in the future. How can we possibly know anything about an event that occurred 14 billion years ago?
Science is too often presented either as a huge database of facts or as an endeavor that is open only to a highly educated group of elite thinkers. It is neither of these. In its essence, science is a process, a way of looking at a question and finding an answer. Step-by-step, scientists look at a problem and ask, “How can I test this to see if it is true?” Asking one question at a time, they have built a body of knowledge too vast to be held in single library.
Although there is the occasional giant breakthrough, in which one person’s insight changes the way we look at things, these are rare and momentous events—Newton and gravity, Darwin and natural selection, Einstein and relativity. And yet even Newton, whose insight stands out among the greatest of scientists, said “If I have seen farther, it is by standing on the shoulders of giants.”
No one person set out to build a cell-phone system. It grew in tiny increments. Long ago, scientists found that radio waves could be transmitted and detected. Others figured out how to modulate those waves in order to reproduce a voice. Miniaturization of electronics with the invention of the transistor played a role. Circuit-printing techniques, battery technologies, digitized signals sorted by computers—each piece of the puzzle came from a different direction.
In this book, I have tried to show some of the background to science questions. To understand why the sky is blue, you have to know a little bit about light and something about the atmosphere. Once you know how the two things work together, the color to the sky makes sense. And it’s also clear why the sky isn’t always blue.