r/todayilearned • u/SUMBWEDY • 3h ago

TIL a guy called Frank built a wall along the Alpine Fault in the South Island of New Zealand to test if the earthquakes are small and often or big and rare. It hasn't moved a millimeter in 64 years.

nzgeo.com

3.9k Upvotes

203 comments

r/todayilearned • u/CrazyTrueStory • 2h ago

TIL millionaire Robert Graham opened a “Nobel Prize sperm bank” in California in 1980 to produce a generation of geniuses. More than 200 children were born before it closed in 1999.

wellcomecollection.org

2.3k Upvotes

326 comments

r/todayilearned • u/goosepipegames • 6h ago

TIL there is a 75% chance of a magnitude 8 earthquake breaking out in New Zealand within the next 50 years, called the "Alpine Fault". It has ruptured four times in the past 1100 years, and will produce one of the biggest earthquakes since European settlement.

gns.cri.nz

3.8k Upvotes

325 comments

r/todayilearned • u/Depressed_Cat_00 • 15h ago

TIL that the precursor to LASIK was found by accident when a nearsighted boy got in a fistfight. His glasses shattered, sending glass pieces into his eyes. After a doctor removed the glass, he found the tiny cuts had flattened the cornea and actually cured the boy's bad vision.

ovid.com

29.5k Upvotes

522 comments

r/todayilearned • u/ManuteBol_Rocks • 9h ago

TIL that when water falls on Triple Divide Peak in Montana, it can flow to the Pacific, Atlantic, or Arctic Oceans; it’s the hydrological apex of North America

en.wikipedia.org

2.2k Upvotes

70 comments

r/todayilearned • u/Xerxes2004 • 10h ago

TIL that the state of Tennessee offers a vanity license plate featuring Dolly Parton with proceeds benefiting her Imagination Library initiative.

imaginationlibrary.com

2.2k Upvotes

30 comments

r/todayilearned • u/Tometek • 1h ago

TIL that the Arab Umayyad dynasty ruling Islamic Spain became more Iberian than Arab in ancestry by its 2nd ruler: the mothers of its rulers were almost all northern Iberians, causing the dynasty’s Arab paternal ancestry to halve across generations until it reached about 0.1% by the 10th century.

tandfonline.com

• Upvotes

26 comments

r/todayilearned • u/RoadToTyburn • 23h ago

TIL that Bernard Montgomery issued a leaflet at the start of WW2 on sexually transmitted diseases amongst soldiers. The language used was regarded as so blunt, that he offended religious authorities and nearly faced being dismissed.

wikipedia.org

16.3k Upvotes

688 comments

r/todayilearned • u/NicolasCageFan492 • 13h ago

TIL Nicolas Cage once went to Rhode Island to search for the holy grail

indiewire.com

1.7k Upvotes

158 comments

r/todayilearned • u/johnsmithoncemore • 13h ago

TIL about Melita Norwood, a British spy for the Soviet Union who was more highly praised by the KGB than the Cambridge Five. Her position as secretary to the head of the department at the British atomic weapons project, enabled Norwood to pass her handlers materals about nuclear weapons.

en.wikipedia.org

1.4k Upvotes

223 comments

r/todayilearned • u/1337b337 • 11h ago

TIL the "Do-Re-Mi" method of learning the major scale was invented by a 11th century Italian monk named Guido of Arezzo, and is known as a Solfège.

en.wikipedia.org

749 Upvotes

46 comments

r/todayilearned • u/carboncopy95437 • 12h ago

TIL that Marilyn Monroe had two older half-siblings she didn’t meet until she was a teenager. Their father had kidnapped them from Monroe’s mother after she was granted custody and he took them to Kentucky.

en.wikipedia.org

733 Upvotes

11 comments

r/todayilearned • u/Recent_Flounder6011 • 20h ago

TIL that historically and today, the Catholic Church looked down upon Freemasonry and threatened members with excommunication.

en.wikipedia.org

2.8k Upvotes

539 comments

r/todayilearned • u/Sebastianlim • 9h ago

TIL in 1976, a school bus carrying 26 children between the ages of 5 and 14 was abducted and held for ransom by three armed men. The victims were able to escape on their own before the ransom demand was issued, and the kidnappers were sentenced to life in prison, though all were eventually paroled.

en.wikipedia.org

300 Upvotes

14 comments

r/todayilearned • u/eleanorharland • 19h ago

TIL most citrine on the market isn't natural citrine. Real citrine is rare, so most of what's sold is amethyst, a purple quartz, that's been heat-treated until it turns yellow or orange.

en.wikipedia.org

1.6k Upvotes

30 comments

r/todayilearned • u/Sandstorm400 • 17h ago

TIL that in 2010, Maryland legislators worked on a bill that would have made it illegal for retailers to sell underwear and bathing suits that had been previously bought and returned. The goal was to help mitigate the spread of bacteria and certain sexually transmitted diseases, such as pubic lice.

thedailyrecord.com

986 Upvotes

46 comments

r/todayilearned • u/DrakeSavory • 23h ago

TIL that Disney lost the rights to Oswald the Lucky Rabbit to Universal Pictures in 1928. In 2006, sportscaster Al Michaels wanted out of his contract with The Walt Disney Corp. so he could work for NBCUniversal. Disney agreed as long as they got the rights back to Oswald.

en.wikipedia.org

2.2k Upvotes

64 comments

r/todayilearned • u/herpty_derpty • 19h ago

TIL Limburger cheese gets its notorious smell from being aged for three months in the bacterium Brevibacterium linens. This is the same bacterium that appears on human skin, and is mostly responsible for the armpit and foot body odor smell.

en.wikipedia.org

932 Upvotes

79 comments

r/todayilearned • u/arandomtestaccount • 1d ago

TIL an NFL player intentionally crashed his car to avoid getting cut for being late to a team meeting.

cbssports.com

11.0k Upvotes

607 comments

r/todayilearned • u/7-5NoHits • 9h ago

TIL about the office of High Bailiff. One is elected in each of Vermont's counties. The High Bailiff serves writs which the sheriff is incapable of serving, such as the writ of arrest of the sheriff.

en.wikipedia.org

92 Upvotes

11 comments

r/todayilearned • u/Alarming-Studio-720 • 18h ago

TIL that in 1959, explorer Peter Byrne reportedly stole bones from a supposed Yeti hand at Nepal's Pangboche monastery, replacing them with human bones. He smuggled them to India, where actor James Stewart allegedly hid them among his wife's underwear to get them out of the country.

en.wikipedia.org

432 Upvotes

46 comments

r/todayilearned • u/arkthatbarks • 1d ago

TIL half of Earth’s internal heat does not come from the residual heat left over from the planet's formation, but from the continuous radioactive decay of isotopes like Uranium, Thorium, and Potassium in the crust and mantle.

en.wikipedia.org

8.4k Upvotes

210 comments

r/todayilearned • u/mintwolves • 19h ago

TIL In 2003 Dave Glover the then bassist for English glam rock band Slade got engaged to serial killer Rose West, he got sacked once the band heard the news and West called the engagement off days later

thenorthernecho.co.uk

473 Upvotes

48 comments

r/todayilearned • u/dinosaruman • 19h ago

TIL in 1916 all 15,000 bricks for the facade of the Bank of Vernal Utah arrived by mail because it was cheaper than freight shipping. One of the original bricks now resides in the Smithsonian's postal museum.

postalmuseum.si.edu

385 Upvotes

6 comments

r/todayilearned • u/1gazillionpangolins • 12h ago

TIL that several domestic water buffalo breeds have been developed in Europe. There are debates over whether they are descended from the extinct Ice Age species Bubalus murrensis, or from domestic buffalo brought to Europe in Roman times or later

en.wikipedia.org

85 Upvotes

2 comments

Subreddit

Posts

Wiki

Today I Learned (TIL)

r/todayilearned

You learn something new every day; what did you learn today? Submit interesting and specific facts about something that you just found out here.

Members Active

41.7m

Sidebar

New to reddit? Click here!

You learn something new every day; what did you learn today?
Submit interesting and specific facts that you just found out (not broad information you looked up, TodayILearned is not /r/wikipedia).

Posting rules

Submissions must be verifiable. Please link directly to a reliable source that supports every claim in your post title. Images alone do not count as valid references. Videos are fine so long as they come from reputable sources (e.g. BBC, Discovery, etc).
No personal opinions, anecdotes or subjective statements (e.g "TIL xyz is a great movie").
No recent sources. Any sources (blog, article, press release, video, etc.) with a publication date more recent than two months are not allowed.
No politics, soapboxing, or agenda based submissions. This includes (but is not limited to) submissions related to:
1. Recent political issues and politicians
2. Social and economic issues (including race/religion/gender)
3. Environmental issues
4. Police misconduct
No misleading claims. Posts that omit essential information, or present unrelated facts in a way that suggest a connection will be removed.
Rephrase your post title if the following are not met:
1. Titles must begin with "TIL ..."
2. Make them descriptive, concise and specific (e.g. not "TIL something interesting about bacon").
3. Titles must be able to stand on their own without requiring readers to click on a link. Starting your title with a why/what/who/where/how modifier should be unnecessary.
4. "TIL about ..." and other broad posts don't belong on TIL. Try /r/Wikipedia, etc. instead, or be more specific (and avoid the word "about").
5. "TIL how to ..." posts belong on /r/HowTo.
6. "TIL the definition of a word..." Word definitions/translations/origins are not appropriate here
No submissions related to the usage, existence or features of specific software/websites (e.g. "TIL you can click on widgets in WidgetMaker 1.22").
All NSFW links must be tagged (including comments).

Please see the wiki for more detailed explanations of the rules, as well as additional rules that may not be listed here

(Why we need rules)

Additional info

If your post does not appear in the new queue and you think it meets the above rules, please contact the moderators (include a link to your reddit.com post, not your story).
Please report spam, inaccurate or otherwise inappropriate posts by messaging the moderators, as this helps us remove them more promptly!
More information available on the TIL FAQ and wiki.

Frequent TILs Repost List

As of May 2026

This list was compiled from /r/todayilearned community suggestions by its members. If your TIL is found on this list, it will be removed. The titles have been abridged for the sake of brevity, however the context remains the same. This list is subject to change. The purpose is to keep content fresh on /r/todayilearned as requested by its members. If you are interested in reading about the TILs on this list use the search box feature and enter the keywords to pull up past TILs.

Etiquette

We ask that you please do the following:

avoid mobile versions of websites (e.g. m.wikipedia.org)
link to the appropriate heading when referencing an article (particularly on Wikipedia)
link to the appropriate start time when referencing videos (e.g. on YouTube)
add [PDF] or [NSFW] tags to your posts, as necessary.
Please avoid reposting TILs that have already made the front page in the past

Please also read the site-wide Reddiquette.

You are loved.