Tag: Physics

When the Night Lit Up: Unraveling the Mystery of a Superbolt Storm | March 21 2026, 12:55

We had a thunderstorm last night. The whole county is buzzing because everyone thinks that something exploded just before midnight. Several posts in a row on social media. In short, it was thunder. But a bit more rare than usual. Caused by a 401 kA lightning, dubbed the Wild House Shaker. A typical lightning strike is 30 kA. If the numbers are to be believed, 401 kA is really damn a lot. They will likely say we haven’t had such lightning here for decades.

Attaching an interesting map.

The points on the map show superbolts — lightning strikes with an energy of no less than 1M J. Red points — particularly powerful superbolts with an energy of more than 2M J. That is, superbolts mostly occur in the northeastern part of the Atlantic and in the Mediterranean Sea, and less frequently — in the Andes, off the coast of Japan, and near South Africa.

this is what the page from which I took the map says (translation):

“New work shows that superbolts most often occur over the Mediterranean Sea, the northeastern Atlantic, and over the Andes, as well as in smaller amounts to the east of Japan, in tropical oceans, and near the southern tip of Africa. Unlike regular lightning, superbolts often strike over water.

“Ninety percent of lightning occurs over land,” said Holzworth (that’s the main guy on lightning at the University of Washington).

“But superbolts mostly arise over water, right up to the coastline. For example, in the northeastern Atlantic, the distribution maps of superbolts clearly show the outlines of the coasts of Spain and England.”

“The average energy of a discharge over water is higher than over land—that we knew,” he said. “But we did not expect such a stark difference.”

The season for superbolts also does not match the usual patterns of lightning. Regular lightning most often occurs in the summer—the three main so-called “lightning chimneys” coincide with summer thunderstorms over America, Africa south of the Sahara, and Southeast Asia. However, superbolts, which are more common in the Northern Hemisphere, occur in both hemispheres from November to February.

The reason for such a distribution remains a mystery. In some years, there are significantly more superbolts than in others: the end of 2013 was record-breaking, and the end of 2014 was the second largest, while in other years such events were much less frequent.

“We speculate that this may be related to sunspots or cosmic rays, but we will leave that for future research,” said Holzworth.

“For now, we are just demonstrating that there is a previously unknown pattern.”

Evolution of Understanding: Brain as a Predictive Model | March 18 2026, 13:29

An interesting philosophical thought came to my mind. What if evolution doesn’t exist in us (not in biological life), but in our system of understanding the laws of the world 🙂 That is, the system of understanding the laws of the world adapts itself so that everything more or less matches up. That is, the brain constructs an internal hallucination and constantly suppresses it in order to minimize the error of prediction. And there’s a big question — does our understanding system strive for truth (absolute correspondence to the world) or just for comfort (so that the picture in the head does not fall apart)?

With this approach, there’s a problem that if you don’t look into the future, then at each iteration, the understanding system adjusts its model so that the prediction works, but simultaneously creates problems for the next iteration, because it has to account for them already. As a result, this layered pie accumulates contradictions and constraints to such an extent that each subsequent theory becomes more and more complex and accreted with a multitude of unexplainable gaps. Dark matter, black hole radiation, gravitational waves, and so forth appear to somehow stretch the owl to fit the globe.

But yes, this is related to the question of whether mathematics was discovered or invented.

Navigating Without GPS: Understanding Cardinal Directions in Moscow | March 13 2026, 18:41

The spokesperson for the Phystech press service explains how to determine cardinal directions in Moscow when navigation systems are down. Find the North Star or use the sun: it rises in the east and sets in the west. Also reminds us how to determine directions using trees. Ziya, do you know how to find cardinal directions using trees? — What’s there to know? Fir tree points north, palm tree points south!

Overall, it seems the Phystech press service is not aware that in Moscow, the annual amplitude of sunrise point movement is almost 90 degrees. That means, it only sometimes (like now, in March) actually coincides with the east. But they do know the word “asterism”. I think most readers will place it somewhere near the word “flatulence”

When Cosines Defy Reality: Humor in the Trenches of Science and War | March 11 2026, 22:00

“Comrades cadets, in wartime the value of cosine can reach 2, and in exceptional cases, when the situation on the fronts demands it, even 3!”

Exploring the Mystical Connection Between π² and g in Defining a Meter | March 01 2026, 17:11

It turns out that π² ≈ g is not some mystical coincidence. When the first scientists contemplated the definition of the meter, there was one elegant proposal: to make the meter equal to the length of a pendulum that takes exactly one second to swing from one side to the other.

For a mathematical pendulum, the period of oscillation is calculated by the formula: T = 2π √(L / g). If we take the length L = 1 meter and set the full period T = 2 seconds (so that it takes exactly one second for each half swing), the equation implies: g = π² (m/s²).

The definition of the meter was later changed: it was tied to one ten-millionth of the distance from the equator to the North Pole along the meridian passing through Paris. However, this geodetic definition was inspired by the earlier idea with the pendulum. Notably, both approaches match up with an accuracy of 1%. Essentially, since the old “pendulum” definition was the main candidate for a long time, values were adjusted so that the new meter was convenient and close to the measurements customary at that time.

It is also interesting that the number of seconds in a year roughly corresponds to the number of pi * 10^7. Earth’s orbital speed is about v = 30 km/s. The distance from the Sun to Earth is approximately r = 150,000,000 km. Thus, over a year, Earth travels a path of about d = 2 * π * r. Then, the orbital period equals T = d/v = π * 2 * r/v = π * 10⁷ seconds.

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.

Unveiling Scientific Misnomers: A Cross-Cultural Exploration | January 14 2026, 04:46

Today I was surprised to learn that the Coriolis force is pronounced as CoriolIs force, not coriOlis force as we were taught in school. I started to investigate what else was wrong, and discovered something amazing.

It turns out what we called Gay-Lussac’s law is known as Charles’s Law in the rest of the world, and what we called Charles’s Law is known throughout the world as Gay-Lussac’s Law.

The Cartesian coordinate system here is Carthesian. Cartesius is just the Latinized name of René Descartes.

In our textbooks, the law of conservation of mass is called the Lomonosov-Lavoisier Law (what enters the chemical reaction = mass of the substances formed). In the rest of the world, it is exclusively the Law of Lavoisier (Lavoisier’s Law). Lomonosov got included here only because “whatever is taken from one body is added to another”.

Also, it turns out that if you have to explain Pythagoras’ theorem to someone in English, without a hint, it’s absolutely impossible to guess that it’s Pythagoras. Greek names are generally a mess. Thales here is pronounced as Teelis.

For some reason, in physics Roentgen is called RentgEnom, although it’s Röntgen with the emphasis on ö.

In Russia, a trapezoid is a quadrilateral with two sides parallel and two not. In the USA, our trapezoid is known as Trapezoid, and the word Trapezium here refers to a quadrilateral with no parallel sides at all. In the UK, it’s the opposite. Our trapezoid is Trapezium, and the “skewed” quadrilateral is Trapezoid.

Comparing US and Russian Higher Education Systems through Credit Hours | December 10 2025, 17:35

Regarding education in the USA and the USSR/Russia. My degree in the USA is evaluated as a Master of Science degree in Computer Science. My younger colleagues say that a Russian university degree is rarely recognized as a Master’s these days, and often hardly qualifies even for a Bachelor’s. I decided to look at the numbers and was very surprised.

To earn a bachelor’s degree in the USA, you need to spend about 2000 hours in classrooms/laboratories. In terms of credits, this equals 120 credit hours. One credit usually equals 1 hour (50 minutes) of lectures per week for a semester (15 weeks). Laboratory work has a different coefficient (often 2–3 hours in the lab count as 1 credit), so the actual number of classroom hours is slightly higher (closer to 2000+).

So, my diploma states that I spent 7908 hours in classes over five years. That’s four times more than the typical student in the USA. Based on the numbers, it turns out that I spent about 2000 hours on math, physics, and English alone over five years, with a total of 42 subjects.

A colleague shared that in his Russian bachelor’s diploma there are 3140 academic hours, which is twice as less. And can you share how many hours are in your diploma?

Year of graduation, university, specialty, and the number of hours? I’m curious about the range of variation.

Navigating Complexity: The Challenge of Wikipedia’s Expert-Driven Content | November 26 2025, 01:06

Wikipedia has one big problem. Well, or we have it with Wikipedia. If you go to almost any Wikipedia page about a relatively complex mathematical or physical concept, you often suddenly don’t want to read it any further. Formally everything is correct there, but the explanation is given through concepts, often even more complex than the concept being explained. Besides, there is often a lot of unnecessary information — what is formally/academically/taxonomically part of the topic, but essentially “pollutes” the first impression.

This problem arises because the authors of Wikipedia (often mathematicians) prioritize rigor and completeness rather than didactics and comprehensibility.

In the English-speaking environment, this is sometimes called “Drift into pedantry”. Articles are often written by experts for experts, not for those who are trying to learn the subject from scratch.

Let’s take, for example, a “tensor”. Imagine a student who has heard that tensors are used in machine learning (Google TensorFlow) or physics and wants to understand the essence.

What the reader expects (intuition): “A tensor is a table of numbers (or some sort of data container) that describes the properties of an object and correctly changes if we rotate the coordinate system”

What Wikipedia provides: “A tensor (from Latin tensus, ‘strained,’ as per the classical layout of mechanical stress at the sides of a deformable cube, see illustration) — is a layout (arrangement in space) of numbers (components), used in mathematics and physics as a special type of multi-index object, possessing mathematical properties.” The article immediately starts listing ranks, covariance and contravariance of indices. This is formally correct but it “pollutes” the first impression.

The illustration at the very top is captioned like this: “Mechanical stress, deforming a cube with faces perpendicular to the coordinate axes, in classic elasticity theory is described by the Cauchy stress tensor, which links 2 indices: the normal vector to the face with the stress vector T (force per unit area); there are 3 directions of normals and 3 directions of stress components, which gives a 2nd rank tensor 3×3 — consisting of 9 components.”

Formally — not a single error. In fact — it’s a wall of text that requires knowledge of linear algebra just to read the definition.

It’s as if you asked “What is an apple?”, and you were responded with: “An apple is a fruit of plants from the subfamily Amygdaloideae or Spiraeoideae, featuring an epicarp, mesocarp, and endocarp, often participating in Newton’s gravitational experiments.”

On one hand, it seems like with the emergence of LLM, Wikipedia is no longer necessary. There are conditional LLMs like ChatGPT, which essentially paraphrase everything that is in Wikipedia in the required form. But they do it because they were trained on Wikipedia, and undoubtedly Wikipedia was given much more weight during training than other internet junk. If there was no Wikipedia in the training set, it would be much more difficult. Meanwhile, Wikipedia is constantly edited, and LLM and Google use it exactly when answering questions.

Therefore, on the one hand, it seems to me that it is high time for Wikipedia to transition to generating on the basis of expert-curated data and packaging knowledge in the required format, for example, in the form of questions and answers. On the other, the whole idea of encyclopedia master-data for LLM/RAG is lost.

The paradox is that LLM is, in essence, the only “interface” that was able to read these pedantic definitions of Wikipedia, “understand” them (through thousands of examples of code and articles) and translate them back into humane language. Wikipedia has become an excellent database for robots, but a poor textbook for people.

The Inner Mechanics of Old Rotary Phones | November 25 2025, 00:59

When I was little, I used to take apart old telephones many times, and only now, in my grey years, I realized that I never wondered how they worked. And they worked in a very interesting way.

Let’s start with the dial. The phone is connected to the network by two wires. The dial is a rotary one. When you wind up the disk, the contacts are blocked, and when you release it, the disk returns backward and delivers a series of interruptions/pulses to the line. But how was it made to return at a constant speed (which is 10 pulses per second)?

It operated based on a centrifugal friction governor. The mechanics (gearbox) accelerated the governor’s axle to thousands of revolutions per minute. Two weights with friction pads (consider them brakes) were seated on the axle. The centrifugal force pressed them against the stationary drum, creating a braking effort. This is a direct heir to Watt’s centrifugal governor, allowing the mechanism to work stably regardless of how sharply you released the disk.

Next. The Central Office connected you with a friend. You both speak at the same time, and sound is transmitted there and back through two wires—why two wires and not four, you understand? Well, okay, but why don’t you hear yourself too loudly, since the microphone sends the sound there, from where the “speaker” hears it?

I couldn’t answer quickly. Went googling. So, it turns out that a special differential transformer was responsible for this. There, the current from the microphone branches off: part goes into the line to the friend, and part goes into the “balance circuit” (a chain of a resistor and capacitor inside the phone), mimicking the line resistance. The transformer coils are wound in opposition: the magnetic flows from the current in the line and the current in the balance circuit mutually annihilate themselves in the coil that goes to the speaker. Engineers purposely adjusted the balance not perfectly, leaving a “local effect” – a quiet sound of one’s own voice, so the phone wouldn’t seem “dead.” But the incoming signal from the friend has nothing to unbalance it (silence on your side), so it freely passes to the speaker.

Now about the microphone. At that time there were no transistors in phones, but the signal was loud. The secret is in the design of the microphone, it’s carbon. Essentially, it is a box with carbon powder and a movable diaphragm. The sound from your mouth compresses and decompresses the powder, changing its resistance. The microphone does not generate current but modulates the powerful current coming from the Central Office. Essentially, it worked as an amplifier. Over time, the charcoal compacted, and the audibility dropped—hence the habit of tapping the handset to “shake up” the powder.

The speaker was normal, electromagnetic. Although not quite. If there were only an electromagnet inside (without a permanent magnet), the phone would horribly distort the voice. An electromagnet attracts iron regardless of the polarity of the current. If you supply a sine wave (voice), the diaphragm would be attracted during both the positive and the negative half-waves. Result: the frequency of the sound would have doubled, and you would hear not the voice of a friend, but an unintelligible high-frequency buzzing. The permanent magnet solves this problem: It creates “preload.” The diaphragm is always attracted to the magnet with medium force. When the “plus” of the signal arrives, the magnetic field strengthens and the diaphragm flexes more. When the “minus” arrives, the field weakens and the diaphragm springs back.

In modern speakers, the force strictly depends on the direction of the current. Plus pushes, minus pulls. Therefore, the frequency doubling, which old phone engineers feared, physically cannot occur here. The diaphragm doesn’t need “preload” by a magnet, it just needs to hang in peace.

Interestingly, the principle of old electromagnetic capsules (metal diaphragm + “anchor”) is used now in the most expensive in-ear headphones—google “balanced armature headphones” (prices around $500).

The voltage in the telephone network was negative – minus 48/60 volts. Plus was grounded, and the “live” wire was the minus. Why? It turns out, this is protection against electrochemical corrosion. The cables lie in moist earth. If there were a “plus” (anode) on the wire, upon insulation damage, copper would dissolve (electrolysis) and the cable would rot. With “minus” (cathode), metal ions, on the contrary, tend to settle on the conductor from the soil, which prolonged the cable’s life by decades.