Absolutely hands down one of the most beautiful places to see from space is the Caribbean. You see an entire rainbow of blue. From the light emerald green to the green-blue to the blue-green to the aquamarine to the slowly increasingly darker shades of blue down to the really deep colors that come with the depths of a really deep ocean. You can see all that at one time from space. It’s very curvy, it’s not harsh geometric lines. It’s swirls and whirls and all kinds of wavy lines. It looks like a piece of modern art.

— Astronaut Sandra Magnus, quoted in Ariel Waldman, What’s It Like in Space?, 2016

Swedish botanist Elias Tillander (1640–1693) was so “harassed by Neptune” during a trip across the Gulf of Bothnia from Stockholm to Turku that he made the return journey overland and changed his name to Til-Landz (“to land”).

Linnaeus named the evergreen plant Tillandsia after him — it cannot tolerate a damp climate.

(From Wilfrid Blunt, Linnaeus: The Compleat Naturalist, 2001.)

From Lee Sallows:

(Thanks, Lee!)

From reader Chris Smith:

Pick a three-digit number in which all the digits are different. Example: 314.

Now list every possible combination of two digits from the chosen number. In our example, these are 13, 14, 31, 34, 41, and 43.

Divide the sum of these two-digit numbers by the sum of the three digits in the original number, and you’ll always get 22. In our example, (13 + 14 + 31 + 34 + 41 + 43) / (3 + 1 + 4) = 176/8 = 22.

This works because 10a + b, 10a + c, 10b + a, 10b + c, 10c + a, and 10c + b sum to 22a + 22b + 22c = 22(a + b + c), so dividing by a + b + c will always give 22.

(Thanks, Chris.)

06/08/2024 Reader Tom Race points out that essentially the same trick can be performed using the entire number: If you add all six permutations of the original 3 digits, then divide that total by the sum of the 3 digits, the answer is always 222.

For example, using 561:

561 + 516 + 156 + 165 + 651 + 615 = 2664

5 + 6 + 1 = 12

2664 / 12 = 222

“This works because in the first sum each of the three digits (a, b and c) occurs twice in each of the three columns, so the sum is 222a + 222b + 222c = 222(a + b + c).” (Thanks, Tom.)

The upside-down catfish, Synodontis nigriventris, is right side up. Or, rather, it’s adapted to spend most of its time upside down — its belly is darker than its back, and it swims fastest in this inverted position. The behavior may have evolved to help it reach food on the undersides of submerged branches or to breathe dissolved oxygen near the surface.

Albert Einstein used to say that he went to his office at the Institute for Advanced Study “just to have the privilege of walking home with Kurt Gödel.” The two would meet at Einstein’s home each day between 10 and 11 and undertake the half-hour walk to the institute. At 1 or 2 in the afternoon they’d walk back, discussing politics, philosophy, and physics. Biographer Palle Yourgrau estimates that these walks consumed 30 percent of Einstein’s workday.

Einstein’s secretary, Helen Dukas, wrote in 1946, “I know of one occasion when a car hit a tree after its driver suddenly recognized the face of the beautiful old man walking along the street.”

Gödel caused no such problems. “I have so far not found my ‘fame’ burdensome in any way,” he wrote to his mother. “That begins only when one becomes so famous that one is known to every child in the street, as is the case of Einstein.”

(From A World Without Time: The Forgotten Legacy of Godel and Einstein, 2009.)

On each of these two black lines is a trio of red points marked by the same distances.

The midpoints of segments drawn between corresponding points are collinear.

(Discovered by Danish mathematician Johannes Hjelmslev.)