Decibel Levels

Decibel levels:

  • 0 – Threshold of human hearing (with good ears)
  • 10 – Human breathing at 3 meters
  • 30 – Theater, with no talking
  • 40 – Residential area at night
  • 50 – Quiet restaurant
  • 60 – Office or restaurant
  • 70 – Busy traffic at 5 meters
  • 80 – Vacuum cleaner at 1 meter; curbside of busy street
  • 90 – Loud factory, heavy truck at 1 meter
  • 100 – Pneumatic hammer at 2 meters; inside a disco
  • 110 – Accelerating motorcycle at 5 meters; chainsaw at 1 meter
  • 120 – Rock concert; jet aircraft taking off at 100 meters
  • 130 – Threshold of pain; train horn at 10 meters
  • 140 – Rifle being fired at 1 meter
  • 150 – Jet engine at 30 meters
  • 180 – Rocket engine at 30 meters
  • 250 – Inside a tornado
  • 1,000 – Eruption of Krakatoa

Schopenhauer wrote, “The amount of noise which anyone can bear undisturbed stands in inverse proportion to his mental capacity.”

Cat as Coauthor

Physicist J.H. Hetherington had already typed up a physics paper in 1975 when he learned of an unfortunate style rule: Physical Review Letters does not accept the pronoun we in single-author papers.

Hetherington didn’t want to retype the paper — this was before word processors had become widespread — so he added his cat as a second author (“F.D.C. Willard,” for “Felis Domesticus Chester Willard.”)

“Why was I willing to do such an irreverent thing? Against it was the fact that most of us are paid partly by how many papers we publish, and there is some dilution of the effect of the paper on one’s reputation when it is shared by another author. On the other hand, I did not ignore completely the publicity value, either. If it eventually proved to be correct, people would remember the paper more if the anomalous authorship were known. In any case I went ahead and did it and have generally not been sorry. Most people are amused by the concept, only editors, for some reason, seem to find little humour in the story.”

Chester is believed to be the only cat who has published research in low-temperature physics. “When reprints arrived, I inked F.D.C. Willard’s paw and he and I signed about 10 reprints which I sent to a few friends,” Hetherington later recalled. “The story has now been told many times and my wife can add that she sleeps with both authors!”

Simpson’s Paradox

Baseball is a game of statistics, but numbers can be deceiving. It’s possible for one batter to outperform another in both halves of the season and still receive a lower batting average:

First Half Second Half Total Season
Player A 4/10 (.400) 25/100 (.250) 29/110 (.264)
Player B 35/100 (.350) 2/10 (.200) 37/110 (.336)

This is an example of Simpson’s paradox, a mathematical quirk that arises occasionally in social science and medical statistics.

Quine’s Typewriter

Harvard philosopher Willard Van Orman Quine typed all his work on an old 1927 Remington typewriter. He had customized it by replacing the 1, !, and ? keys with specialized mathematical symbols.

Someone once asked him how he managed to write without using a question mark.

“Well, you see,” he replied, “I deal in certainties.”

Calendar Switch

Europe hit a bump in 1582 when it switched from the Julian calendar to the Gregorian: to realign the equinox, Pope Gregory XIII decreed that October 4 would simply be followed by October 15. This didn’t go over well — servants demanded full pay for the missing time, and people objected to “losing” 10 days of their lives.

At least they got it over with. Protestant England and the American colonies put off the switch until 1752, when they had to skip 10 days in September. “Take this for your consolation,” wrote Ben Franklin in his Almanack, “that your expenses will appear lighter and your mind be more at ease. And what an indulgence is here, for those who love their pillow to lie down in Peace on the second of this month and not perhaps awake.”

Russia stayed on the Julian calendar until it became the Soviet Union — according to the Gregorian calendar, the “October Revolution” actually took place in November.

Disposition by the Nose


1. Large Noses.–Bonaparte chose large-nosed men for his generals, and the opinion prevails that large noses indicate long heads and strong minds. Not that great noses cause great minds, but that the motive or powerful temperament cause both.

2. Flat Noses.–Flat noses indicate flatness of mind and character, by indicating a poor, low organic structure.

3. Broad Noses.–Broad noses indicate large passage-ways to the lungs, and this, large lungs and vital organs and this, great strength of constitution, and hearty animal passions along with selfishness; for broad noses, broad shoulders, broad heads, and large animal organs go together. But when the nose is narrow at the base, the nostrils are small, because the lungs are small and need but small avenues for air; and this indicates a predisposition to consumptive complaints, along with an active brain and nervous system, and a passionate fondness for literary pursuits.

4. Sharp Noses.–Sharp noses indicate a quick, clear, penetrating, searching, knowing, sagacious mind, and also a scold; indicate warmth of love, hate, generosity, moral sentiment — indeed, positiveness in everything.

5. Blunt Noses.–Blunt noses indicate and accompany obtuse intellects and perceptions, sluggish feelings, and a soulless character.

6. Roman Noses.–The Roman nose indicates a martial spirit, love of debate, resistance, and strong passions, while hollow, pug noses indicate a tame, easy, inert, sly character, and straight, finely-formed Grecian noses harmonious characters. Seek their acquaintance.

From Searchlights on Health: The Science of Eugenics, by B.G. Jefferis and J.L. Nicols, 1920

Star Wars Hit Probability Equation

From Bespin to Yavin, the “Star Wars Hit Probability Equation” predicts the outcome of any battle:

n is the number of “bad guys,” x is the number of “good guys,” and J is the number of Jedi present (if any).

The equation reads, “The probability of a bad guy hitting his target is equal to the inverse of all bad guys present plus the cube of the number of good guys present (plus one) plus the number of Jedi present (plus one) to the 10th power.”

So the presence of a good guy reduces the bad guys’ accuracy, and having even one Jedi present is bad news for the Empire.