Exploring Xplor Park: An Engineer’s Marvel in Riviera Maya | June 29 2025, 05:41

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.

Unveiling Ancient Numeric Codes in “Slave for Sale” by José Jiménez Aranda | June 27 2025, 21:00

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.

Exploring Maya Ruins and Termite Tunnels in Playa del Carmen | June 27 2025, 18:59

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.

The Surprising Origins of Chain Link Fencing | June 26 2025, 10:08

Deception is everywhere. I googled “chain link fence” and it turns out that Karl Rabitz has nothing to do with it, but instead relates to a different one, and the very first of the known documented images of the chain link fence was found in… a mattress patent. More precisely, in the US patent No. 124,286 “Wire Fabrics”, issued on March 5, 1872, to a certain Mr. Peters (J. W. C. Peters).

Faustian Dialogues in Modern Project Management | June 20 2025, 15:00

I think project managers can very well speak to developers in the words of Faust.

Well, here we go again, in the old manner

With you – all is uncertainty, all doubts,

In everything you create difficulties,

And for all, you wish for new rewards!

When will you, without any further talk, —

One, two: look, — and everything is ready soon!

(For context – this is Faust’s reaction to the refusal of the seemingly omnipotent Mephistopheles (Devil) to bring Helen of Troy and Paris from the realm of shadows to the stage for the Emperor’s amusement)

director

Don’t forget anything:

What can be done immediately,

Why put it off till tomorrow?

We must instantly grasp

All that is necessary and possible

(…)

“You have poorly executed it,

And left a gap in the corner”

And the designer might reply:

And you do not see, how vile and shameful

This craft?

Am I not an artist?

To the Manager:

“Fire! Help! Hell! We are all going to burn now!”

Unraveling the Layers of Echidna: From Faust to Mythology | June 13 2025, 04:21

In the second part of Faust, he encountered an echidna and realized that he did not understand

“Oh wonder! The clew turned into an egg,

The egg swelled up — what is within?

Two dreadful twins emerged —

A vampire with an echidna — from the egg.

The echidna writhes here crawling,

The vampire hovers under the ceiling”

It turned out that in the lexicon of the 18th-19th centuries, an echidna was a venomous snake. I mean, sarcastic, spiteful, sharp, cunning, mocking me, of course, I know this word, but that it literally signified a snake, I learned for the first time. And in Greek mythology, the half-woman half-snake Echidna was apparently the mother of Hydra, Sphinx, Chimera, and Cerberus

Heightened Alert: Navigating Uncertainty and Vigilance | June 12 2025, 22:56

“Due to increased regional tensions.” The Consular Affairs office of the State Department in its notice advised U.S. citizens to “exercise increased caution.” Such news always reminds me of this picture.

Preserving History in Metal: The Story of U.S. Historical Markers | June 08 2025, 13:24

A rather useful thing was invented in the USA. How do you make sure that history is preserved for centuries? Books burn, the internet is obviously a temporary phenomenon. Across the entire US territory stand these signs called Historical Markers. There are already over 220,000 of them. They are practically indestructible — these are raised letters on a thick metal plate. Often there’s a quite wordy paragraph on them, and they are placed not only in recreational areas but often in places where you can neither drive up to them nor easily walk up. For example, you’re driving on a highway where you can’t go under 40 miles per hour, and there’s nowhere to stop, and somewhere off the road in the field there’s a marker for deer about some battle. Well, apparently, they believe that when they will be needed, there won’t be a problem in accessing them.

Navigating the Cosmos: Newton, Halley, and the Birth of Modern Science | June 03 2025, 03:01

I’m currently re-reading A Short History of Nearly Everything by Bill Bryson. An old book from 2003. For instance, the author celebrates that Pluto was finally recognized as a planet by the IAU. So, there’s this interesting story about scientific startups in the 17th century.

Everyone knows from school that Isaac Newton is the father of classical mechanics and gravity concepts, and authored a fundamental work that underpins all subsequent physical science: “Mathematical Principles of Natural Philosophy,” or simply “Principia.”

There was also Halley—the one after whom the comet was named, and then there was Hooke, who discovered the cell (and Hooke’s law of elasticity and loads of other stuff).

So in 1684, Halley, discussing the problem of planetary orbits with Robert Hooke and Christopher Wren, asked, “What force makes the planets move in elliptical orbits?” Hooke claimed it was a force inversely proportional to the square of the distance, but he could not prove it strictly. Halley went to Cambridge to ask Newton directly—and to his astonishment, Newton said that he had already proven it. Moreover, he promised to send a detailed account. Actually, he got a bit carried away and instead of simply answering the question, he wrote three volumes of “Principia” (and deliberately wrote it in a complicated way to discourage the uninitiated).

As the work on “Principia” was nearly complete, Newton and Hooke disputed over who first discovered the inverse-square law of force, and Newton refused to release the key third volume that made the first two volumes sensible. Thanks only to tense diplomacy and the most generous doses of flattery from Halley, the fussy professor eventually agreed to release the final volume. Without Halley’s interest and prodding, Newton probably would not have formalized his discoveries into a cohesive work.

The Royal Society had promised to publish the work but then declined, citing financial difficulties. The year before, the society had funded a costly flop called “History of Fishes,” and suspected that a book on mathematical principles would hardly stir market excitement.

Halley, whose financial situation was modest, paid for the publication from his own pocket. Newton, as was his habit, contributed nothing. To make matters worse, just then, Halley had taken a position as the society’s clerk, and was informed that the society could no longer pay him the promised salary of 50 pounds a year.

Instead, they decided to pay him with copies of the History of Fishes. The society handed him 50 copies of the same History of Fishes” (apparently intended for fireplace use).

About several hundred copies of “Principia” were released—a rather large print run for such an expensive book, yet the publication aroused no interest from the reading public. The book sold very poorly, and the publishing did not pay off at all. Even in 1739, 53 years after the publication, an inventory check found the Society still had 126 copies left, and these were being sold at huge discounts, given away, or virtually given away for free.

Ironically, one of the most influential texts in the history of humankind was considered virtually a commercial failure at the time.

And it’s funny that since its publication in 1687, there was a calculation error in the text that wasn’t noticed until 1987, 300 years later, by a student, Robert Garisto, a senior at the University of Chicago.

In sentence eight (the book used such numbering) Newton tried to confirm his theory by calculating the mass, the force of gravity at the surface, and the density of known planets. To calculate mass, he needed to know the angle between the line from the center of the Earth to the Sun and the line from a point on the Earth’s surface to the Sun.

Modern measurements give this value as about 8.8 arcseconds (one second is 1/3600 of a degree). Newton thought it was 10.5 seconds, but mysteriously used 11 seconds in the actual equation. This error was discovered by Garisto when he was redoing the calculations as part of a regular class assignment.

This Robert Garisto is now an editor of Physical Review Letters. He recently made headlines a second time when his journal published a scientific paper with 5,154 authors 🙂