You might wonder about the photos used in the header. They are color photos from a time (pre-1915) when photos were black and white. It took an ingenues process called “trichrome color photography” to record them and a modern-day (2004) computer to restore them, giving us photos in full color, seemingly ordinary by today’s standards.

Computer program developers in particular will recognize the zeal and perseverance it most have taken the photographer Sergei Mikhailovich Prokudin-Gorskii and the computer scientist Blaise Agüera y Arcas to produce them. They will also recognize the insouciant way people accept the result.

For more information visit the Library of Congress.