TIL that 911 Medals of Honor were revoked after the 1917 Medal of Honor Review Board raised the standards necessary for its awarding. Most of those revoked were awarded during the American Civil War simply for reenlisting. [Source]

TIL The United States stores 94% of all electricity in the form of water reservoirs, not in a battery. [Source]

TIL that the Gateway Arch in St. Louis, MO is considered a national park. At 192.83 acres, it is the smallest national park in the U.S., being less than 2% the size of the next smallest park, Hot Springs National Park in Hot Springs, AR. [Source]

TIL That Caffeine Has An Average Half Life of 5 Hours [Source]

TIL Mexican general Manuel Mier y Terán warned that Texas was slipping from Mexico’s control, and after watching his country descend into chaos and ignore his warnings, he fell on his sword in 1832 [Source]

TIL that of the 574 federally recognized tribes in the United States, 229 of them are in Alaska (40%) [Source]

TIL Aldyn-ool Sevek was a master of Mongolian throat singing whose sound was said to be impossible to reproduce; he died of throat cancer in 2011. [Source]

TIL about Cpt. Henry Elrod, a Marine aviator who shot down two Japanese aircraft, sank a warship, landed his disabled plane, and organized a ground defense which repulsed enemy attacks on Wake island where he was mortally wounded. [Source]

TIL before Pope Francis, the last pope to have a unique papal name was Pope Lando (913-914) [Source]

TIL a 14,000 year old puppy buried in Germany survived canine distemper which kills most dogs in under 3 weeks. Archaeologists concluded that its Stone Age owners nursed it through the horrible illness. Then they buried it with them when it died. [Source]

TIL that cockroach milk is one of the most nutritious substances on Earth — 3x richer in calories than buffalo milk — and researchers are already looking into using it in cosmetics and health products. [Source]

TIL the PDF file format was invented by Adobe more than 30 years ago (in 1993) [Source]

TIL of Chevalière d'Éon. Assigned Male at Birth, d'Éon was legally recognized as a Woman at age 50 by King Louis XIV in 1777 [Source]

TIL Friday the 13th (1980) was panned by critics upon release. Gene Siskel was a vocal critic of the film, going so far as to publicly spoil the ending in an attempt to convince audiences not to see it and encourage detractors to write to actress Betsy Palmer and express their contempt for the film. [Source]

TIL the “Great Oil Sniffer Hoax” fooled French state oil company Elf Aquitaine in the 1970s into spending over $150 million on planes that supposedly detected underground oil from the air, before the technology was exposed as a fraud. [Source]

TIL When Benedict Arnold's home town learned he had betrayed the revolution and burned their neighboring New London harbor, they got so mad they dug up his father's grave and threw his bones in the river. [Source]

TIL the White Beaches, a stretch of sandy coastline located in Tuscany. The unusual color of the sand is the result of years of processing and discharge of calcium carbonate by a chemical plant located about a kilometer from the coast. Due to that, they are among the most polluted beaches in Italy [Source]

TIL Capt. Charles McVay committed suicide in 1968 after being wrongly blamed for the USS Indianapolis disaster. For over 20 years, he received letters from grieving families calling him a murderer, he was cleared of all charges posthumously in 2001. [Source]

TIL 13 residents of St. Paul's River in Quebec, which only has a population of about 150, bought lottery tickets (along with one other person from a nearby village) collectively for nearly 20 years before they won a $50 million jackpot. Each person in the group of 14 received a $3.5 million share. [Source]

TIl that industrialist Andrew Carnegie spent $56.2 million to build 2509 libraries across the world. Known as Carnegie Libraries, cities had to follow a strict maintenance commitment to obtain funding. Today, there are an estimated 900 Carnegie Libraries operating in the United States. [Source]

TIL that in Full Metal Jacket (1987), director Stanley Kubrick let R. Lee Ermey improvise much of his dialogue, and sometimes only required 3 takes per scene. This was highly unusual for the meticulous director, who almost never allowed improvisation and typically took 40 takes or more per scene [Source]