It turns out that the incline (incline, or grade) – the steepness of a road or slope – has quite an obvious definition, but I never really thought about it. It means the ratio of the projection of a line on the terrain to the vertical plane to the projection of the same line on the horizontal. In other words, the magnitude of the incline equals the tangent of the angle between the rise of the slope and the horizontal (the tangent of the angle of inclination).
Thus, a “steep climb” sign of 10% indicates just about 5.71 degrees of inclination. This is arctan(0.1).
It also turned out that formally among specialists when reading the notation, the “%” sign is pronounced as “hundredths.”
I am looking at photos and reading material about the Milky Way and noticed that the word galaxy (any) essentially means “milky” from Greek. Κύκλος Γαλαξίας. Essentially, lac from lactose, and gala from galaxy essentially come from the same Proto-Indo-European ģlákts. Unexpected.
I returned from Mexico — visited Xplor Park by Xcaret in Riviera Maya. The park is already 18 years old, but damn, it’s an engineering feat, not just a park. As an engineer, I was walking around with my mouth open.
The park is the size of Moscow’s “Neskuchny Garden”. A significant part consists of kilometers of natural karst caves, formed millions of years ago at the site of the Chicxulub impact crater (the very one that ended the era of dinosaurs). Above the caves are dense jungles. High above the jungles — kilometers of zip lines. The water in the caves is from a natural underground stream, which is filtered through limestone plus some technical structures. Bats fly around, but obviously, they are not wild and are working for food. No wildlife (other than tourists and bats) is present, so it’s pretty well isolated from the outside world. In these kilometer-long caves, completely covered with stalactites and stalagmites, we swam, rafted, and even drove through in amphibious vehicles with gasoline engines (meaning, the ventilation is well-thought-out).
In front of us, three Mexican women failed to control their vehicle and crashed into a tree. Literally — the front wheels of the buggy were above my head. We picked them up walking along the track, sat them back, and about 5-10 minutes down the road, park workers took them away. The girls have something to remember.
The ticket includes a very, very good buffet restaurant. But pictures are essentially a must-buy — a very thoughtful system designed to extract about 100 dollars from a visiting family. Helmets are embedded with a chip, the system classifies the pics on the fly, and at the exit, you can see all your photos and buy them right there. And on the way back to the hotel, you can post on Facebook or Instagram.
Well, we’re back home now, back to work from Monday.
Interesting. I learned, for example, that the human retina is not really attached to the vascular tunic, but is held in place only mechanically by intraocular pressure. Because of this, those who jump from heights or engage in diving, and generally anything that increases intraocular pressure, are at risk of retinal detachment.
(By the way, about pressure, I had a slight barotrauma in my left ear today during airplane landing: after landing there was a lingering feeling of stuffiness and muffled sounds, and while in the air it even hurt a bit. That is, some traces of sensation remained several hours later, but probably, by tomorrow morning I will recover fully).
An interesting painting “Slave for Sale” (Una Esclava en Venta), 1897, by Spanish artist Jose Jimenez Aranda.
From it, I learned that just as there were Roman numerals, there were Greek ones in Greece. Pay attention to the plate. It reads ΡΟΔΟΝ ΕΤΩΝ ΙΗ ΠΩΛΕΙΤΑΙ ΜΝΑΣ Ω, which translates to “Rhodon, 18 years old, for sale for 800 minae”.
In the Greek text, there are two numbers – ΙΗ and Ω. In those times, Greeks wrote numbers using letters: Α (alpha) = 1, Β = 2, …, I = 10, K = 20, …, Ρ = 100, Σ = 200, …, Ω = 800.
Accordingly, ΙΗ is 18. The line above it indicates that it is a number, as does the line above Ω.
Here in Playa del Carmen, there are about a dozen abandoned Maya-era buildings that you can climb over and into, of course free of charge and at any time. Inside one of them, in a small room, I found interesting termite mud tunnels, which I had never seen in person before.
On the shore, a lone woman was seen engaging in an unequal battle with the world ocean. Armed with a shovel, she heroically moved the sargassum two centimeters to the left, apparently to a place designated for them by feng shui. To the left and right to the horizon—nobody.
This weird thing appears on the phone and you can’t close it, it just keeps popping up again and again, every second. For about five minutes. It’s almost impossible to use the phone. Turns out, there’s a guy sitting one seat away from me on the plane, opening and closing an AirPods case, chatting with a girl. He’s got nothing better to do with his hands, darn it.
Hi, I'm Rauf Aliev. 