A number is divisible by 3 if the sum of its digits is divisible by 3.
A number is divisible by 4 if the number formed by the last two digits is divisible by 4.
A number is divisible by 8 if the number formed by the last three digits is divisible by 8.
A number is divisible by 9 if the sum of its digits is divisible by 9.
Science & Math
Homebodies
Only about 400 people have ever left Earth’s atmosphere. Only 12 have walked on the moon.
Overachiever
Mount Everest is getting taller.
It rises by about 2.5 centimeters each year.
Straight and Narrow
An optical illusion.
The horizontal lines are parallel.
Well, Hey!
How to Cure Cancer. — Boil down the inner bark of red and white oak to the consistency of molasses; apply as a plaster, shifting it once a week; or, burn red-oak bark to ashes; sprinkle it on the sore till it is eaten out; then apply a plaster of tar; or, take garget berries and leaves of stramonium; simmer them together in equal parts of neatsfoot oil and the tops of hemlock; mix well together, and apply it to the parts affected; at the same time make a tea of winter-green (root and branch); put a handful into two quarts of water; add two ounces of sulphur and drink of this tea freely during the day.
— Barkham Burroughs’ Encyclopaedia of Astounding Facts and Useful Information, 1889
Diet of the Desk Worker
Just how much food the brain worker needs is a question which has not yet been decided. In general it appears that a man or a woman whose occupation is what we call sedentary, who is without vigorous exercise and does but little hard muscular work, needs much less than the man at hard manual labor, and that the brain worker needs comparatively little of carbohydrates or fats.
Many physicians, physiologists and students of hygiene have become convinced that well-to-do people, whose work is mental rather than physical, eat too much; that the diet of people of this class as a whole is one-sided as well as excessive, and that the principal evil is the use of too much fat, starch and sugar.
— Public School Domestic Science by Mrs. J. Hoodless, 1898
Fallen Astronaut
There’s only one piece of art on the moon: Fallen Astronaut, an 8.5-cm aluminum sculpture of an astronaut in a spacesuit. It’s meant to honor astronauts and cosmonauts who died furthering space exploration … but it’s also a testament to the almost limitless patience of its creator.
Belgian artist Paul Van Hoeydonck agreed to the project after meeting astronaut David Scott at a dinner party. Making art for the moon is pretty demanding in itself — it has to be lightweight, sturdy, and tolerant of temperature extremes. But NASA also said the figure couldn’t be identifiably male or female, nor of any identifiable ethnic group. On top of that, because Scott wanted to avoid the commercialization of space, they didn’t want to make Van Hoeydonck’s name public.
The artist agreed to all this, and in 1971 Apollo 15 put Fallen Astronaut on the moon, along with a plaque listing 14 fallen space explorers. Van Hoeydonck even agreed to create a replica for the National Air and Space Museum “with good taste and without publicity.”
But he finally balked when Scott tried to talk him out of selling 950 signed replicas for $750 apiece at New York’s Waddell Gallery in 1972. A guy’s got to make a living.
Coincidence?
ELEVEN PLUS TWO is an anagram of TWELVE PLUS ONE.
Forward and Back
Temperature palindromes:
16° Celsius ≅ 61° Fahrenheit
28° Celsius ≅ 82° Fahrenheit
Katrina’s Eye
Hurricane Katrina, seen from the inside. It was the sixth-strongest Atlantic hurricane ever recorded, and the costliest in U.S. history. Total damages are expected to reach $75 billion.