Finished reading The Life of Isaac Newton. It was dry to my taste, but still okay. It’s hard to read any history after experiencing David McCullough’s books.

I’m not sure many people appreciate how different the world was before and after Newton. His contributions weren’t the only ones that mattered, but they were profoundly significant. He used prisms to demonstrate that white light is composed of all the colors of the spectrum. He invented calculus (independently, though simultaneously, with Leibniz). He formulated the laws of motion. He discovered universal gravitation—an idea that sounds absurd at first: everything attracts everything else! Before him, the cosmos seemed governed by mysteries or divine intervention; after him, it was ruled by discoverable, mathematical laws. He also helped formalize the scientific method.

One thing the book does well is showing what a complicated person Newton was. He was smart, but also combative, suspicious, and vindictive. I would even go further and call his personality unpleasant. His obsession with quarrels was at odds with his intellect.

This contrast between his achievements and his difficult personality makes reading his biography challenging but also more interesting. The challenging part comes from my brain’s desire to have a coherent picture of someone, but life is not like that.

I do not know what I may appear to the world, but to myself I seem to have been only like a boy playing on the seashore, and diverting myself in now and then finding a smoother pebble or a prettier shell than ordinary, whilst the great ocean of truth lay all undiscovered before me.

Moria

From It is link winter on X:

The truth on X is what random people commentate, polarize, interpret, and summarize from source material that is intentionally lost by a black box algorithm. There is no depth to anything on X because context with links is heavily penalized.

Getting off Twitter was one of the best decisions I made in the past year. My life has become much calmer.

I recently registered on Bluesky, and after a few minutes I couldn’t understand why I’d want to spend time there. It’s interesting how your perspective changes once you step away. You start to see it differently — as a giant arena where everyone is shouting, countless things are happening, yet nothing meaningful ever really occurs.

Found a wonderful website and a book — Motion Mountain. The book explores the many wonders of everyday life:

Using hundreds of stories, pictures, films, tables and puzzles, five volumes tell about sport, raindrops and animal life (mechanics, gravity and heat), about moving empty space and the sky at night (relativity and the structure of the universe), about lightning, lasers and nerves (electricity, optics, the brain, language and truth), and about colours, pleasure and the stars (quantum physics, nuclear physics and radioactivity). A sixth volume tells about the search for a final, unified theory of physics.

Surprisingly, I’ve stumbled upon it by accident and have never seen it recommended anywhere on the mainstream internet.

Also from the website:

Truthfulness — combined with politeness — make the world a better place.

Geometry for FLPE 2.24

Solving this exercise via force components is straightforward, leading to the answer $x$. However, I struggled with solving it using the principle of virtual work.

The hardest part of this exercise was calculating how the weight moves when we displace the cart. For simplicity, I reflected the diagram horizontally, aligning the movement with the standard x-axis.

One important point is that we cannot simply multiply the displacement by $^$, as this does not account for the fact that the weight moves along a circular path due to the rope.

I arrived at the following diagram, and the solution became clear from its geometry. In this diagram, the card moves to the right and $AB = x$.

We can approximate the path of the weight by a straight line, as the angle of the rope will be small. Thus, we obtain:

${\displaystyle \mathrm{\angle }ACB=90^{\circ }⟹AC=AB\cdot \cos 30^{\circ }=\mathrm{\Delta }x\cdot \cos 30^{\circ }}$

Finally, we arrive at the correct answer:

${\displaystyle \mathrm{\angle }AOC=90^{\circ }⟹OC=AC\cdot \sin 30^{\circ }=\mathrm{\Delta }x\cdot \cos 30^{\circ }\cdot \sin 30^{\circ }}$

I would be interested in solving this analytically by equating the equation for a circle with that of the plane to find the coordinates of the point. Ultimately, for the principle of virtual work, we only need to determine $\frac{\delta y}{\delta x}$.

If anyone stumbles upon this post and finds such a solution, please feel free to send a copy to $@$.

Eiermann Desk

Last year I was looking for a new desk. My main requirement was that it should be lower than 70 cm. Most desks today are 75 cm high, which is too tall for most people. I also wanted to avoid the Silicon Valley vibe that is so ubiquitous in modern workspaces.

Eventually, I found the table I loved — the Eiermann 1. The original table frame was designed in 1953, either for Eiermann’s own office or for his students; history differs on this point. The crossbar, made in one piece, is placed diagonally between the sides. This reduced construction achieves the perfect balance between material and stability. The tabletop lies flat on the frame. Less is not possible.

It’s been almost a year and it still brings me joy every time I sit at it.

It’s been almost two months since I bought Feynman’s exercises. I didn’t expect physics to capture my attention this much. I’ve finished six chapters and created 200 new Mochi cards since then.

The exercises turned out to be the key to understanding. There were many times when I read a chapter, thought I understood it, but then found myself lost when trying to solve a practical problem. There must be a reason for this phenomenon. My guess is that it’s easy to confuse familiarity with understanding. Reading gives you the sense of the tools you can use, but it doesn’t teach you how to use them.

Doing exercises highlighted how much I’ve forgotten from mathematics. As a refresher, I skimmed through Lang’s Basic Mathematics. I started going through Spivak’s Calculus, which has even more exercises than the Feynman’s books.

This experience makes me wonder how it’s possible to cover everything in university. Sometimes I spend days thinking about a single problem. I don’t know if you can afford that when you have other subjects to study.