Tag: Environment

Jet Trails as Weather Predictors: A Phenomenon of High Altitude Humidity | January 24 2026, 02:34

Walking with Yuki, I see across the sky a very distinct and narrow streak clearly (apparently, an airplane had passed by), and usually a contrail disappears quite quickly, but today it is unusually sharp and long.

I started to investigate and it turns out this is a reliable indicator of changing weather, specifically the arrival of snow or rain: as we are actually expecting a sudden knee-deep snowfall tomorrow. In short: the airplane trail acts as an indicator of humidity at high altitudes.

Here’s how it works:

For a contrail not to evaporate but to start “smearing”, the air at an altitude of 8–10 kilometers must be very humid (saturated with moisture). If the air is dry, the ice crystals from the engine quickly turn into invisible vapor (sublimate). If the air is moist, the crystals have nowhere to evaporate. Instead, they start attracting extra moisture from the surrounding environment and grow. High humidity at high altitudes is a sure sign of an approaching warm atmospheric front.

Navigating the Future: Embracing Earth’s Magnetic Field as a GPS Alternative | January 10 2026, 17:41

I learned today that there is and is actively used a technology for navigation using the Earth’s magnetic field. It is used as a replacement or an extension of GPS.

For example, there is the Scandinavian ferry Express 5 of Bornholmslinjen, which insures against GPS problems (which do happen) by using MagNav navigation. Unlike GPS, the Earth’s magnetic field cannot be jammed or spoofed—it simply exists. The ferry follows the same route, and generally, navigation could even be achieved through household fishing sonars.

But there are a few startups that use this technology for indoor navigation, where GPS signals cannot reach. It’s claimed that the navigation accuracy is within 1 meter. That’s more interesting.

GiPStech, Oriient, Mapsted.

The basis of this technology is a process called magnetic fingerprinting. Engineers or mapping robots walk through a building with a smartphone, recording unique distortions of the magnetic field at every point. These distortions are created by the steel frame of the building, rebar in the walls, and large electrical equipment. A database is formed where each coordinate (x, y, z) corresponds to its unique magnetic field vector (intensity, inclination, deviation).

The collected data is uploaded to the cloud platform of the provider company. There, they undergo noise cleaning and are “stitched” together with the digital floor plan. When a user walks through a shopping center, their smartphone reads data from the built-in magnetometer in real-time. Special software (SDK) compares the current readings with those stored in the database. For accuracy to be within 1–2 meters, the system relies not only on magnets. It uses sensor fusion—combining data from the magnetic field with inertial sensors (accelerometer counts steps, gyroscope determines turns) and sometimes Wi-Fi/Bluetooth signals for rough localization.

This technology is certainly being actively implemented for drones. The main technical difficulty there is dealing with their own interference and considering that the magnetic field changes, requiring constant map updates. Electrics, engines create strong magnetic fields, which “drown out” the natural background of the Earth. However, various filtering algorithms (including neural networks) are used, which in real-time “subtract” motor interference from the overall sensor readings. From what I understand, at high altitudes (kilometers), the magnetic field is more “smooth”, therefore the accuracy is lower (about 1–5 km). But if several drones fly together and exchange signals, overall they can provide very good accuracy each. Additionally, a group of drones can measure the gradient (rate of change) of the magnetic field in space, tying location not to absolute values, but to relative ones. Essentially, using a group of drones turns the navigation system from a set of individual receivers into a distributed phased array antenna, capable of filtering global interferences and working with much weaker useful signals. Considering that small drones capable of staying airborne for long periods can be released into the air by the hundreds (and cost pennies), this is a quite promising area for military.

There’s an interesting startup, Zerokey. They release QUANTUM RTLS 2.0. This device provides spatial accuracy to 1.5mm. It’s used in production, for example. Their video shows a “watch” on a worker’s hand that monitors the correctness of assembling something on a table. Here, the principle is ultrasonic, and it’s understandable that these “watches” are paired with stationary sensors and further multilateration.

Capuchins in Costa Rica: Monkey Antics and Natural Insecticides | January 03 2026, 20:55

In the photo — a white-shouldered capuchin. Took this pic in Manuel Antonio, Costa Rica a week ago. At that moment, a troop of at least 40-50 monkeys stormed the beach: they were everywhere. Scrambling through bags, one started to pull out a towel but couldn’t manage it. They’ve already figured out how zippers work. Capuchins have rather scary sharp teeth, but it seems they don’t use them on people without reason.

While preparing this post, I decided to read up a bit about them. Turns out, they practice so-called “self-anointment” — they rub their fur with crushed ants or centipedes. The chemicals (like formic acid) released by these insects act as a potent insecticide, deterring parasites. Also, if a capuchin finds a lemon or wild onion, it will crush them into a pulp and thoroughly “perfume” itself with the juice.

Capuchins have very complex social bonds, which they maintain in very specific ways. They have “trust testing” rituals that might seem odd to a human. Two monkeys can sit and alternately stick their fingers deep under each other’s eyelids. This is the supreme form of trust — “I allow you to hurt me because I trust you.” Also, they can insert their fingers into each other’s nostrils and sit like that for a long time, entering a sort of trance. I’ll put links in the comments.

Dangerous Beauty: The Spiked Palms of Costa Rica’s Jungles | January 03 2026, 02:35

A very typical palm for Costa Rican jungles. Hugging one of these is a bad idea. These black spikes are incredibly sharp, hard, and can reach lengths of 10-15 centimeters. They are arranged in dense rings along the entire trunk. The most treacherous thing about these spikes is their fragility and dirt. If a person or animal runs into such a spike, the tip easily breaks off and remains deep in the wound. Since in the tropical climate these needles are home to millions of bacteria and fungi, a deep splinter almost guarantees a serious, painful, and slow-healing inflammation.

The density of the needles varies, sometimes the trunk is not visible behind them.

Such was the case in the series Pluribus.

Exploring Nature’s Design: How Insect Bites Transform into Palm Leaf Patterns | January 03 2026, 02:15

This is a palm leaf in the jungle about 60-70 centimeters wide. I stopped and wondered how it is that beetles chew through to create such a pattern.

I mean, when you think about it, the answer is obvious. They make one hole in a folded leaf, and then the leaf unfolds, creating many holes – like a paper snowflake. Upon contemplating this, I realized that palm leaves grow as a “cigar,” a rolled-up tube. I didn’t know this, but the very regular holes leave no other explanation.

But there is another thing – the holes are a bit large for a beetle or an ant. Obviously, if they were to eat a leaf that’s rolled up into a tube, they would end up biting through several layers at once, because if they ate the layers separately, the structure wouldn’t appear as regularly. But their mouths aren’t huge enough, of course, to eat such multi-layered leaves.

Apparently, an ant or beetle was eating the leaf while it was still small. Afterwards, the leaf grows evenly throughout and, obviously, the hole increases along with the leaf. The holes don’t heal; the leaf is alive and grows. A hole made by a beetle could initially be only a couple of millimeters in size, but then it grows to the size of a finger.

Exploring the Golden Carpenter Ants of Costa Rica | December 31 2025, 14:28

Golden Carpenter ants from my last trip to Costa Rica. They are huge, about 1.5cm. They build nests in wood. Unlike termites, they don’t eat the wood, they just make a home for themselves there. They don’t have stingers, but if disturbed too much, they can bite with their jaws (as seen in the photo on the left) and inject formic acid. Their distinctive feature is a golden abdomen. I’ll write about other notable leaf-cutter ants next time, half of my phone is full of them.

Exploring the Monkey Species of Costa Rica’s Forests | December 29 2025, 22:47

In the forests of Costa Rica, several species of monkeys were encountered. The most interesting are the coatis. They live quite high up, but the trail also went up the mountain slope