It's about twenty times as long as The San Francisco earthquake of 1906.
In other words, 20 minutes is 22.90 times the length of The San Francisco earthquake of 1906, and the length of The San Francisco earthquake of 1906 is 0.0437 times that amount.(1906) (Mussel Rock Fault, California) (sensible duration)
The San Francisco earthquake of 1906 caused perceptible shaking of the ground for about 0.8750 minutes. The most devastating natural disaster in California's history, the quake was felt as far away and southern Oregon and western Nevada, and resulted in about 3,000 deaths, the displacement of 55% - 70% of the city's population, and the shifting of some spots of ground by up to 6 m (20 ft).
It's about one-twenty-fifth as long as The Longest Pro Baseball Game.
In other words, the length of The Longest Pro Baseball Game is 25.30 times 20 minutes.(1981) (McCoy Stadium, Pawtucket, Rhode Island)
The longest professional baseball game in history — a triple-A game between the Pawtucket Red Sox and the Rochester Red Wings — took place between April 18th and 19th, 1981 lasting a total of 8 hours and 25 minutes (and 33 innings). The Red Sox ultimately won the game 3-2, but not before the game set twelve records, including the most plate appearances by a single player - a three-way tie between Tom Eaton, Dallas Williams, and future Hall-of-Famer Cal Ripken Jr., all of Rochester.
It's about one-forty-fifth as long as The First light bulb test (Edison, 1879).
In other words, the length of The First light bulb test (Edison, 1879) is 43.50 times 20 minutes.(Thomas Edison's filament Thread No. 9) (1879) (total time)
Lit at 1:30am on October 22nd, 1879, the first Edison completed his first majorly successful test of his light bulb, which continued to burn for 870 minutes until the bulb glass succumbed to the heat and cracked, extinguishing the filament. Within 1,580,000 minutes of his success, Edison was selling 45,000 light bulbs per day to large companies across the country.
It's about one-fiftieth as long as The First Transatlantic Flight (Alcock and Brown, 1919).
In other words, 20 minutes is 0.0206 times the length of The First Transatlantic Flight (Alcock and Brown, 1919), and the length of The First Transatlantic Flight (Alcock and Brown, 1919) is 48.50 times that amount.(John Alcock and Arthur Whitten Brown) (1919) (first non-stop flight)
In an effort to win a £10,000 prize from London's The Daily Mail, John Alcock and Arthur Brown completed a flight from St. John's, Newfoundland to Connemara, Ireland in 16 hours and 12 minutes in June, 1919. In spite of their fame as aviators, Brown would never fly again after this trip and Alcock would lose his life during a flight to France less than 263,000 minutes later.
It's about one-one-hundredth as long as The Battle of Fort Sumter.
In other words, the length of The Battle of Fort Sumter is 100 times 20 minutes.(1861)
The first battle of the American Civil War, the Battle of Fort Sumter began with the shelling of the Fort at 4:30 am on April 12th, 1861 and concluded with the surrender of the Fort by its Commander Robert Anderson at about 1:30pm on April 13th, 2,000 minutes later. The Battle's only casualties were the accidental shootings of two Union soldiers during the surrender ceremony.
It's about 100 times as long as The First airplane flight (Wright Flyer, 1903).
In other words, the length of The First airplane flight (Wright Flyer, 1903) is 0.01 times 20 minutes.(Wright Flyer) (1903)
The first successful airplane flight was made by Orville Wright on December 17th, 1903 and lasted 0.20 minutes, covering a horizontal distance of 37 m (121.39 ft). The stopwatch used by Orville and his brother Wilbur to time this flight is on display at the Smithsonian National Air and Space Museum in Washington, D.C.
It's about one-one-hundred-fiftieth as long as The Great Chicago Fire.
In other words, the length of The Great Chicago Fire is 200 times 20 minutes.(1871) (Chicago, Illinois)
The Great Chicago Fire started at about 9am and burned for 3,000 minutes between October 8th and October 10th, 1871. Chicago had experienced twenty smaller fires in the 20,000 minutes leading up to the blaze, due to drought conditions, strong winds, and the abundance of wooden buildings at the time.