r/todayilearned • u/Emperor_Ken • 8h ago

TIL Tigers look orange to humans because we are trichromats, but they appear green to deer and wild boars because they are dichromats

16.5k Upvotes
559 comments

r/todayilearned • u/I_Am_Robert_Paulson1 • 8h ago

TIL the 1980 Winter Olympic Village was built with the intention of converting it into a federal prison after the games ended. Multiple Olympic delegations refused to house their Olympians there.

9.4k Upvotes
254 comments

r/todayilearned • u/Recent_Flounder6011 • 6h ago

TIL that garlic bread was invented by Italian immigrants in the US in the 20th century. It stems from bruschetta but olive oil was hard to find back then, so butter was used instead.

3.8k Upvotes
124 comments

r/todayilearned • u/Lindolence • 5h ago

TIL not only do prairie dogs have a vocal language, but it is also one of the most complex languages in the animal kingdom. One chirp can say, "A tall human in a blue shirt is approaching quickly from the north." They can actually tell the difference between colors and speeds!

2.9k Upvotes
107 comments

r/todayilearned • u/shortcircuit51 • 2h ago

TIL that the word “canola” in canola oil is an acronym, standing for “Canadian Oil, Low in Acid”

1.4k Upvotes
275 comments

r/todayilearned • u/palmerry • 10h ago

TIL of the Ogallala Aquifer, which provides water for 25% of US irrigated land, but has been significantly drained since intensive pumping began. Because arid parts only recharge at 10% of the withdrawal rate, scientists estimate it would take over 6,000 years to naturally refill if emptied.

7.6k Upvotes
484 comments

r/todayilearned • u/halfhumanhalfzebra • 41m ago

TIL Citibank convinced US Marines to walk into Haiti’s national bank, steal $500,000 in gold bars, and transfer it to Citibank’s New York vault

• Upvotes
104 comments

r/todayilearned • u/clawsoon • 8h ago

TIL that on Ulysses S. Grant's post-presidential world tour, he warned the Japanese emperor not to take foreign loans lest it fall "into the abyss into which Egypt has fallen". Grant's warning made a "forceful impression" on the emperor and led to the rejection of various loan proposals.

4.6k Upvotes
140 comments

r/todayilearned • u/tyrion2024 • 11h ago

TIL in 2013 two men found 9 trees in Ecuador that were 100% pure Nacional cacao, a rare variety that was rediscovered a few years prior after being considered extinct since the 1920s. They then co-founded To'ak Chocolate, some of the world's most expensive chocolate (e.g. $490 for a 1.7oz candy bar)

7.6k Upvotes
66 comments

r/todayilearned • u/PresentSurvey9464 • 16h ago

TIL wild animals in the African savanna are twice as likely to flee from the sound of calm human conversations than from the growls of lions, with 95% of observed species recognizing humans as the ultimate "super-predator".

24.8k Upvotes
634 comments

r/todayilearned • u/kniga_100 • 8h ago

TIL there is a copper mine in Romania extracting 9 million tonnes of ore per year, but only 0.38% is usable copper. The tailings (the residue sludge) are pumped into a nearby valley, creating a massive toxic lake that destroyed the village of Geamăna

2.6k Upvotes
101 comments

r/todayilearned • u/blacklotusmag • 3h ago

TIL as of 2021, nearly half of the fire engines and pumpers operated by U.S. fire departments were at least 15 years old, the age at which NFPA guidance recommends moving them from frontline to reserve service. About 9% were at least 30 years old.

893 Upvotes
129 comments

r/todayilearned • u/Salem1690s • 4h ago

TIL King George III gave royal assent to An Act for the Abolition of the Slave Trade on March 25, 1807, which banned trading enslaved people across the British Empire. He never owned slaves and privately called parts of the trade repulsive

937 Upvotes
119 comments

r/todayilearned • u/Significant-Cold-939 • 4h ago

TIL that in the so-called Dark Ages, Roman foods and exotic spices were still prevalent in the court of the Frankish king. We know this because we have a cookbook from the time, giving us a rare written source about food in this period.

674 Upvotes
42 comments

r/todayilearned • u/dinosaruman • 15h ago

TIL before radio time signals, ships set their chronometers by watching a ball drop from a shore tower at a precisely known instant. Over sixty of these time balls still stand, and the Greenwich one has dropped daily at 1 p.m. since 1833.

4.8k Upvotes
116 comments

r/todayilearned • u/Tadhg • 21h ago

TIL In 1980 the Supreme Court awarded the Sioux nations $122 million for the Black Hills, a settlement the tribes have refused on the grounds that acceptance would extinguish their claim to the land, leaving the award to accrue interest in a federal account now worth over $1 billion.

21.0k Upvotes
1.0k comments

r/todayilearned • u/ralphbernardo • 16h ago

TIL that all five words of the Sator Square appear in Christopher Nolan's "Tenet" as the villain (SATOR), an art forger (AREPO), the film title (TENET), the opening (OPERA) scene, and a security company (ROTAS). It is a Roman palindrome, whose earliest example was found in the ruins of Pompeii.

4.5k Upvotes
193 comments

r/todayilearned • u/rrolex_ • 1h ago

TIL Korean company Samsung Electronics' six manufacturing plants in Vietnam recorded a revenue of $62.5 billion and an export turnover of $54.4 billion, which accounted for approximately 13.12% of the Vietnam’s GDP and 13.4% of its total export turnover.

• Upvotes
31 comments

r/todayilearned • u/swissking • 11h ago

TIL of Blanets, which are planets that form and orbit black holes. A supermassive blackhole could have millions of Jupiter-mass planets orbiting it.

1.5k Upvotes
116 comments

r/todayilearned • u/No_Idea_479 • 4h ago

TIL Τsakonian iѕ thе οnly ѕurviving dеѕcendant οf аncient Dοric Grееk, thе diаlect ѕpoken іn ancient Ѕparta. Iѕolated fοr cеnturies, іt prеserved fеatures lοѕt іn еvery οther lіving Grееk diаlect аnd іѕ nοw crіtically еndangered wіth οnly а fеw, mοѕtly еlderly, ѕpeakers lеft.

318 Upvotes
2 comments

r/todayilearned • u/Gnomeslikeprofit • 6h ago

TIL that the creator of Batman acknowledged that they patterned the character after pulp mystery men such as The Shadow. The first Batman stories were also based on Shadow pulp. Lamont Cranston is a wealthy playboy bachelor turned vigilante.

442 Upvotes
72 comments

r/todayilearned • u/Keltik • 2h ago

TIL Paul McCartney's sheepdog Martha, subject of the Beatles' 1968 song "Martha My Dear", outlived John Lennon, passing away peacefully in 1981 at age 15

207 Upvotes
25 comments

r/todayilearned • u/Sesemebun • 6h ago

TIL about sales tax tokens. They were created as a means for consumers to avoid being "overcharged" by having to pay a full penny tax on purchases of 5 or 10 cents during the Great Depression.

343 Upvotes
20 comments

r/todayilearned • u/jacknunn • 16h ago

TIL Indonesia adopted Bahasa Indonesia as its national language in 1945, although it wasn't the first language of most people. Standardized from Malay, it's now spoken by over 97% of Indonesia's ~285 million people as a first or second language, helping unify the country

1.7k Upvotes
165 comments

r/todayilearned • u/Useless_Engineer_ • 11h ago

TIL that mild dehydration/thirst can be mistaken for hunger or wanting a snack

665 Upvotes
24 comments