The Alchemy of Us: How Humans and Matter Transformed One Another

The term circadian rhythm refers to biological processes that humans, animals, plants, and microbes undergo every 24 hours. These processes, which may be physical, mental, or behavioral, respond primarily to light and dark. Ramirez discusses circadian rhythm in Chapter 5, which concerns the invention of artificial light. After detailing Wallace’s carbon arc lamp and Edison’s electric light bulb, Ramirez discusses the effects of artificial light on humans. Too much artificial light at night disrupts the circadian rhythm, hinders the body’s ability to repair itself, and may result in health problems. Research shows that people who work nights, such as surgeons and security guards, have an increase in the risk of cancer and heart disease. Although more studies are needed, the relatively low rates of breast cancer in blind women support the theory that exposure to artificial light at night is detrimental to human health. 

Named after its inventor, Louis Jacques Mandé Daguerre, the daguerreotype is an early photographic process that was widely used in the mid-19th century. A daguerreotype is a unique black-and-white image formed on a highly polished silvered copper plate. Daguerreotypes are sharp and detailed. Frederick Douglass, one of the most photographed men of the 19th century, touted daguerreotype photography as a democratic medium because it allowed people of all stations of life to get images of themselves: “The humblest servant girl, whose income is but a few shillings per week […] may now possess a more perfect likeness of herself than noble ladies and even royalty” (104). For Douglass, the daguerreotype “converted the planet into a picture gallery” (104). The invention of the flexible film roll made daguerreotypes obsolete. 

Pig iron is molten crude iron. In 1855, Henry Bessemer experimented with pig iron to create steel. He blew air directly into the bottom of a molten metal bath with a pipe, which resulted in a volcano-like eruption. The technique removed excess carbon from the pig iron, converted the material into malleable iron, and allowed Bessemer to reintroduce the precise amount of carbon to make steel. Producing steel was difficult before Bessemer’s invention. Facilitating steel production led to the creation of railroads, which affected long-distance travel and changed the nature of commerce in the US.

Two Black Polaroid employees, Ken Williams and Caroline Hunter, formed the PRWM. Its goal was to force Polaroid out of South Africa. The movement relied on activists and the media to spread information about Polaroid’s activities with the apartheid government. After seven years of demonstrations, the PRWM succeeded in forcing Polaroid to withdraw from South Africa. Nelson Mandela later traveled to the US and thanked the PRWM for its efforts.