Today I Learned

Created: May. 4, 2020
Modified: Oct. 11, 2020
Tags: meta, personal



Saccadic masking is the phenomenon where human brains block visual processing while the eyes are moving so that we don't perceive motion blur from those eye movements. The brain creates the illusion of continuity during these brief moments of blindness by inferring the missing visual information and committing those inferences to memory.


The Carrington Event was a huge solar storm in 1859. During the event, auroras were visible as far south as the Caribbean and telegraph systems all over the world failed. Some telegraph operators reported that they could continue to send and receive messages even though their systems were disconnected from any source of electricity.

Between 1977 and 2014, the government of the Philippines waged an on-again-off-again campaign against a violent Islamic nationalist group known as the Moro Islamic Liberation Front or MILF for short.

The Younger Dryas were a climatic event, roughly 12,500 years ago, during which temperatures in the Northern Hemisphere temporarily reverted to glacial conditions.

Mauritania did not criminalize slave ownership until 2007 and has done little to actually enforce its anti-slavery laws since then. A 2018 estimate suggested that 21 of every 1000 people in Mauritania were still enslaved at that time.

A punkahwallah was a servant who worked a manual cooling fan, often operated through a pulley system. Apparently the deaf were favored for this obsolete occupation, as they could not overhear confidential conversations happening around them.

The Astor Place Riot occurred in 1849 in New York City. The riot was started over a dispute about which of two famous Shakespearean actors was better than the other. Another ridiculous New York City riot was the 1922 Straw Hat Riot. It was sparked when a tradition of “hat bashing” (knocking straw hats off of wearers’ heads and stomping on them if the hats were worn after September 15th) spiraled out of control. In yet another strange example of nominative determinism, many of the arrested rioters were sentenced by the Magistrate Peter A. Hatting.

The Ghost Army was a tactical deception unit of the U.S. Army during WWII that utilized inflatable tanks, sound trucks, fake radio transmissions, and other deceptions in order to create the appearance that troops were deployed in locations where they were not.


Little's Law, which states that, for a queue, the average number of items in queue (L) is equal to the average rate at which new items arrive (λ) times the average time an item spends in queue (W). So, L = λ * W. Useful for estimating one feature of a queue based on the other two features.

Chirality is the property of lacking a mirror image that can be created via rotation or translation. The classic example of a chiral object is the human hand.


The Eye of the Sahara is an eroded igneous rock dome that looks like a giant eye when viewed from above. The effect is like something out of science fiction.

The Diomede Islands are two remote islands, located roughly in the middle of the Bering Strait. The international date line runs directly between them, so despite being only 3.8 kilometers from each other, they observe a 20 or 21 hour time difference from each other.

Magnitogorsk, literally “the City of the Magnetic Mountain”, is an industrial city that served as the Soviet Union's primary steel production facility during World War Two. Also, the city's flag is badass.

Shibam Hadramawt is a town in Yemen known for its mudbrick high-rise buildings. These houses, which range from 5 to 11 storeys, are among the tallest mudbrick structures in the world, and are unusually old examples of vertical construction.


In Vim, invoking the gf command while the cursor is over a file path will open that file in a new buffer.

In Rust, there is the unreachable!() macro. Fine. But there is also the (vastly superior) xkcd_unreachable!().


The (campy, terrible) Bond film Live and Let Die includes a scene where Bond uses the backs of three crocodiles as stepping stones to skip across a water channel. Turns out this stunt actually used live crocodiles. Insane.

A fleuron is a typographic ornament, typically a stylized version of a leaf or flower. A sort of archaic precursor to dingbats.

The catoblepas is a legendary creature, probably inspired by real-life encounters with wildebeest, that was said to have had a killing gaze similar to a gorgon or basilisk. Prior to learning about this, I had wondered why the Gorgons in Heroes of Might and Magic III looked like bulls, rather than the more typical medusa.

The chiroplast was a sort of wooden hand brace used to train “proper” hand positioning for piano players.