Einstein–Szilard letter

Facsimile of the Einstein–Szilard letter

An illustration of Cantor's diagonal argument (in base 2) for the existence of uncountable sets . The sequence at the bottom cannot occur anywhere in the enumeration of sequences above.

Piles of new Notgeld banknotes awaiting distribution at the Reichsbank during the hyperinflation

Trump's tweet activity from his first tweet in May 2009 until June 2020

Einstein–Szilard letter

Two physicists — Einstein and Szilárd — mailed Roosevelt a single page in August 1939. Roosevelt read it, wrote 'This requires action,' and set in motion the Manhattan Project, which employed 130,000 people.

Cantor's diagonal argument

Cantor showed in 1891 that the infinity of real numbers cannot be listed — proving it by constructing one number guaranteed to be missing from any list. Infinity has a size hierarchy; most people never heard it.

Battle of Isandlwana

At Isandlwana, January 1879, 1,300 British regulars were annihilated by a Zulu force of 20,000 — partly because a quartermaster refused to issue reserve ammunition without the proper paperwork.

Quinta da Regaleira

A Portuguese millionaire built an inverted tower tunneling 30 meters straight down into bedrock, lit by a single shaft of light, for Rosicrucian and Masonic initiation rituals. The estate has no church, only crypts.

Scipionyx

One baby Scipionyx, dead 113 million years ago, still holds its liver, intestines, and windpipe in anatomical position. It is the only dinosaur fossil with soft organs visible to the naked eye.

Hyperinflation in the Weimar Republic

By 1923, a single egg cost 80 billion marks; workers were paid twice daily so wages didn't lose value before lunch. The wheelbarrow was worth more than the cash inside it.

Tesem

The Tesem, a sleek prick-eared hound depicted on pre-dynastic pottery circa 4000 BCE, was buried in pharaonic tombs with its own name-stele and food offerings. Amenhotep II had four interred with him at death.

Use of X by Donald Trump

Trump tweeted 'South Africa' and 'large scale killing of farmers' after a Tucker Carlson segment in August 2018 — Pretoria summoned the U.S. ambassador within hours and land prices dropped before markets closed.