AVE8890453: Light shines from white powder in metal scoop on stand in laboratory. / Bridgeman Images

AVE8890475: A building on private grounds with trees. / Bridgeman Images

AVE8890482: Cars and trucks drive down busy city street at night. / Bridgeman Images

AVE8890487: A student does homework in an armchair. / Bridgeman Images

AVE8890489: A traffic guard guides children across the street. / Bridgeman Images

AVE8890495: A formal building on well-kept grounds. / Bridgeman Images

AVE8890501: Horses graze in pasture. / Bridgeman Images

AVE8890502: Two boys stand by fire in deserted area, throwing wood on fire. / Bridgeman Images

AVE8890508: Families at a playground by a highway. / Bridgeman Images

AVE8890509: A formal building on well-kept grounds. / Bridgeman Images

AVE8890511: A construction site by a large building complex. / Bridgeman Images

AVE8890518: 1960s: woman standing at lab table talks to seated men and women while pointing to lab apparatus with glassware and stands / Bridgeman Images

AVE8890523: People walk on a university campus. / Bridgeman Images

AVE8890527: 1960s: woman operator types at IBM keypunch machine as cards move horizontally and then are rolled upwards into a stack, stack of paper is next to her / Bridgeman Images

AVE8890528: A man in a Scottish kilt playing a bagpipe. / Bridgeman Images

AVE8890536: A vehicle drives by a construction site by a large building complex. / Bridgeman Images

AVE8890538: 1960s: USA flag. / Bridgeman Images

AVE8890543: 1960s: 3 men in suits and ties sit at a table with a map and papers spread over it; they talk and point with pens at various papers / Bridgeman Images

AVE8890553: 1960s: cross-section of a geode cut in half, showing concentric rings inside with number "1" on it, 2nd geode section appears, 2 fingers point to them, hands move them closer so they touch / Bridgeman Images

AVE8890556: People sit on benches outside Innsbruck ski resort. People use ski lift and walk into building. / Bridgeman Images

AVE8890559: 1960s: cross-section of a geode cut in half, showing concentric rings inside with number "2" on it, finger points to number "2" / Bridgeman Images

AVE8890563: 1960s: crowd walks and sits at outdoor picnic under large trees in park, election poster for candidate on tree / Bridgeman Images

AVE8890564: 1960s: Bald men with glasses in Gray coat pauses on city street to scratch his neck. Man waits to cross street as traffic drives by. Man chews gum. / Bridgeman Images

AVE8890565: A person drives a tractor down a dirt path in a field, another person in tow. / Bridgeman Images

AVE8890568: 1960s: industrial plant with large tanks, smokestacks and pipes with railroad cars in front / Bridgeman Images

AVE8890569: 1950s: Man stands at top of hill after hiking, breathing visibly. / Bridgeman Images

AVE8890578: Somebody digs soil around an iris plant. / Bridgeman Images

AVE8890590: A person dips a hand into water and points out some white flowers growing on an underwater plant. / Bridgeman Images

AVE8890591: A wide river surrounded by mountains. / Bridgeman Images

AVE8890601: A person dips a hand into water and points out a green underwater plant. / Bridgeman Images

AVE8890604: Finger points to the words "Unexplored Region" on a map of southern Africa. / Bridgeman Images

AVE8890609: 1960s: Workers drive tractors and bulldozer over road under construction. Construction vehicles build road near farm field. / Bridgeman Images

AVE8890611: Men guide the unloading of a tank container from a train. / Bridgeman Images

AVE8890615: Young woman asks questions of a woman standing in a sliding glass door. Young man takes notes in a binder. / Bridgeman Images

AVE8890619: The roots of an underwater plant. / Bridgeman Images

AVE8891028: 1960s: Man picks burrs from border collie in tent. / Bridgeman Images