What makes a watch the most valuable in the world? It’s supercomplicated – literally. In 1925 banker Henry Graves Jr. (considered the greatest watch collector of the 20th century) commissioned Patek Philippe to create a unique gold pocket watch. When Graves finally received it – eight years later – it was the most complex timepiece ever created by human hands... (Photo by Suzanne Plunkett/Reuters)

“The Boeing X-45 unmanned combat air vehicle is a concept demonstrator for a next generation of completely autonomous military aircraft, developed by Boeing's Phantom Works. Manufactured by Boeing Integrated Defense Systems, the X-45 was a part of DARPA's J-UCAS project”. – Wikipedia

Photo: Two X-45A Unmanned Combat Air Vehicles (UCAV) are shown to members of the news media July 11, 2002 at Edwards Air Force Base, California. The X-45A, developed by The Defense Advanced Research Projects Agency and the Boeing Company, is the first unmanned system designed from inception for combat missions. (Photo by David McNew/Getty Images)

Recruits who earned a place in the Motivation Platoon struggle through water and muck on their way to becoming a Marine or going into some other line of work, October 7, 1971. (Photo by Eddie Adams/AP Photo)

A cow decorated with charms, colorful ropes and beads is seen as the local cattle breeders who prepared sash, loincloth and their local clothes known as “bush vest” before coming to plateau, their animals in Trabzon, Turkiye on September 24, 2023. (Photo by Hakan Burak Altunoz/Anadolu Agency via Getty Images)

Scarlett Zelaya, 10, of Woodbridge, VA cools off under a water mister while visiting the Smithsonian National Zoological Park on Wednesday July 21, 2021 in Washington, DC. (Photo by Matt McClain/The Washington Post)

Australian performers illuminated with real clocks titled “The Time Minder” attend a media preview of the Night Festival in Singapore on August 23, 2017. Singapore's arts and heritage district will be transformed into Singapore largest outdoor performing arts festival to celebrate its 10th year edition Night Festival from August 24 to 26. (Photo by Roslan Rahman/AFP Photo)

A thirty-year-old Dutch demonstrator displays a sign that reads: “Glad to be Gay” during a gay people march in Frankfurt, Germany on Saturday, July 28, 1979 which ended a week long homosexual meeting. Hundreds of homosexual converged for a week of movies, theater, rock concerts and workshops on gay rights. (Photo by Rolf Boehm/AP Photo)

People enjoy spring break festivities ahead of an 8pm curfew imposed by local authorities, amid the coronavirus disease (COVID-19) pandemic, in Miami Beach, Florida, U.S., March 27, 2021. (Photo by Marco Bello/Reuters)