‘Astrophysics for People in a Hurry’ presents an introductory overview of a rather complicated science. Neil deGrasse Tyson weaves a masterful tale of space and time into this small volume, giving us a history of his chosen profession along the way.
Far from dry and boring, his descriptions of the various elements of interest to the astrophysicist read like the biographies of actors in a star-studded cosmic saga, rather than a mere overview of the periodic table.
Additionally, Tyson expounds on the mysteries of dark matter and dark energy; light and magnetism, and how the measurement of these allows us to peer into the universe. He gives us a sense of cosmic scale—ranging from individual molecules which form the building blocks of everything we know, to the massive expanse of the observable universe.
Tyson’s enthusiasm for his craft reveals itself throughout the book, becoming quite contagious as he recounts the stories of various ‘accidental’ discoveries which enabled his branch of science to reach its present sophistication.
Our natural ability to observe the universe is limited. The use of optics began to expand this ability—just as the microscope enabled Van Leeuwenhoek’s discovery of single-celled organisms, the telescope allowed for the observation of stars and galaxies previously invisible to the naked eye. Until 1800, however, the scope of our sky-peering was limited to visible light. In that year, English astronomer William Herschel began experimenting with prisms.
Prisms have been used to divide light into its component colors for hundreds of years—in the 1600s, Sir Isaac Newton used one to establish that the seven colors of the visible spectrum are red, orange, yellow, green, blue, indigo, and violet. Herschel’s idea was to measure the temperature of each individual color to see if there was any variation across the spectrum. To do this, he placed thermometers at the appropriate locations along the rainbow, as well as a thermometer outside of the spectrum, adjacent to red—he needed to measure room temperature so that he could compare the other measurements against a control.
As he suspected, different colors registered different temperatures. Much to Herschel’s surprise, however, his control thermometer rose even higher than red—indicating the presence of something outside of the visible light spectrum. He had discovered a new band of light—infrared light.
Others built upon Herschel’s experiments, and in 1801 Johann Wilhelm Ritter discovered another band of invisible light adjacent to violet on the spectrum—ultraviolet light.
Bell Labs accidentally contributed to two additional advances in the mid 1900s—the discovery of radio waves emitting from the Milky Way galaxy around 1930, and the discovery of the ‘cosmic microwave background’ in 1964. These accounts benefit from Tyson’s masterful storytelling, so I’ll let you discover them in the book.
I’ll close with a quote from the book on the importance of perspective:
During our brief stay on planet Earth, we owe ourselves and our descendants the opportunity to explore—in part because it’s fun to do. But there’s a far nobler reason. The day our knowledge of the cosmos ceases to expand, we risk regressing to the childish view that the universe figuratively and literally revolves around us. In that bleak world, arms-bearing, resource-hungry people and nations would be prone to act on their “low contracted prejudices.” And that would be the last gasp on human enlightenment—until the rise of a visionary new culture that could once again embrace, rather than fear, the cosmic perspective.