Month: July 2025

Exploring the Slug: An Unusual Imperial Unit of Mass | July 15 2025, 20:52

Have you ever heard of a unit of mass measurement called a slug? In the US, it does exist, even though it’s less common nowadays. American physics and engineering textbooks for students, especially where they want to clearly differentiate between mass (slug) and weight (lbf), tend to use the imperial system with its feet and the like. It simplifies F = ma in the imperial system without introducing extra coefficients.

1 slug is the mass that accelerates by 1 ft/s² under the force of 1 pound-force (lbf). Thus, a slug accelerating at 32.174 ft/s² “weighs” 32.174 pounds-force (lbf). 32.174 ft/s² is our 9.8 m/s², just in feet.

A “slug” is, on one hand, a slug (a slow-moving mollusk without a shell), and on the other hand, a heavy piece of metal or a bullet (like a shotgun slug – a large-caliber cartridge). In the context of the unit of mass, it’s not about mollusks, but rather about a “heavy lump.” But it’s still funny when they write “mass equals 5 slugs.”

12 slugs equal 1 blob (image of blob attached). Blob is a version of slug, but based on inches instead of feet. It has fun slang names – slinch, slugette, snail.

I also read about the British Thermal Unit — the amount of heat needed to heat 1 pound of water by 1°F. Converting BTUs to calories or joules results in a quite awkward number.

AI-Powered Smart Glasses: Revolutionizing Real-Time Discussion and Information Access | July 15 2025, 20:19

Here’s what would be great to do with AI – a system that reads the screen, listens to what’s being discussed on the call, including what you say, and what is said to you, and _on the screen_, and better yet, directly on smart-glasses, gives pop-up tips and hints that help you timely ask a counter-question or request a clarification, or respond to a question directed at you. Not just for passing interviews, although that would also be nice, but for more effectively conducting discussions — from technical to commercial ones.

In the case of smart-glasses, you could enjoy this without a computer in front of your eyes. I’m just afraid of having to send absolutely everything that happens around you to the cloud, analyze it, and return it in real time, which is technologically challenging (=expensive).

Such a system would be no less useful for conducting interviews than for passing them. For example, you ask someone a question, they start to respond, and then the system suggests — aha, it seems they are struggling with this topic. Let’s ask this question. Then you decide whether to ask this or something else. Why not? It’s convenient. Of course, the interviewee could employ the same system, and then it would not be simple.

Right now, I’m flipping through a book by Johannes Itten on color, and I think about how I miss dynamic illustrations and commentary. I’ve reached Piero della Francesca and for the life of me, I can’t recall what his paintings are like. This is where smart-glasses would come in handy. You look at a word, snap your fingers, and around it appear pop-up windows with contextual illustrations, comments, and links to detailed information, which you can visit now, or save to read later. It would be possible to ask any question verbally while looking at the text segment it pertains to and get an answer not verbally, but in a pop-up window that you can quickly close if you didn’t find anything new, or perhaps add a clarification by voice, after which the content in the window updates.

If I had smart-glasses, I would experiment with this. It seems straightforward.

Pearls and Mother-of-Pearl: Nature’s Fascinating Defense Mechanism | July 14 2025, 20:58

I realized that I don’t know much about pearls and started reading up on them today. It turns out that pearls are formed as a natural defense by oysters to irritation: when a micro-particle (a grain of sand, a piece of shell, or a microorganism) gets into the shell, the oyster begins to cover it with layers of nacre. Nacre (nacre) — the inner layer of shells, thin layers of calcium and protein. Interestingly, nacre and pearls are essentially the same in composition. The word “nacre” comes from German and means “mother of pearl” (Perlmutter). A single layer of nacre can form several times a day to several weeks, and it takes up to 2 years for a full pearl to form.

Wild pearls are extremely rare (one in 10000), as not all mollusks are capable of producing them — only some species can. There is also black pearl, found only in the southern part of the Pacific Ocean, and the colors of natural pearls vary from white and grey to green, blue, and red.

Most of the pearls on the market are cultured: humans manage to “trick” the oyster by placing a bead or a piece of fabric inside the shell so it starts the process of covering it with nacre. In other words, to put it simply, almost all the pearls in the market have a plastic bead inside, and nacre is just a thin “skin” around it. Cultivation of pearls occurs on special farms, where oysters are provided ideal conditions for growth and are regularly cared for. The mortality rate of mollusks after transplant is between 10-40%.

Pearls can burn: this is an organic material (97% calcium and 3% water and proteins), and it does not withstand high temperatures, it also dissolves in vinegar.

It turns out, edible oysters also produce pearls, but they are not as shiny.

The Art of Lawn Striping: Creating Light and Dark Patterns with Grass | July 14 2025, 14:42

We constantly drive past fields organized into stripes or checks. I finally found the time to look into how this is done. It’s called lawn striping, and the effect is achieved by bending the blades of grass in different directions.

The direction in which the grass bends determines whether a stripe will be light or dark. When the blades lean away from you, the lawn looks lighter because the light reflects off the broad and long surface of the blade. When the blades lean towards you, the lawn appears darker because you are looking at the tips of the blades (smaller reflective surface) and you see shadows under the grass. Therefore, mowing the lawn in opposite directions (up/down, left/right, north/south, east/west, etc.) creates the greatest contrast between the stripes. Interestingly, since the “color” of the stripe depends on the direction from which you look at it, a light stripe will appear dark if viewed from the opposite side.

This fuss over grass is a very American phenomenon. I overcome my laziness to mow the lawn only when the grass has indecently overgrown (the notion of “indecently overgrown” is also something I adjust each year after receiving tsk-tsk letters from the village administration). My neighbor, however, seems to do it every few days, and I once saw him kneeling in the grass—complaining that someone had dragged something across his lot, dropping some chips in the grass and ruining its perfection. Really, the only thing missing was a pair of scissors in his hands.

The Multi-Functional M1 Helmet: Beyond Battlefield Protection | July 14 2025, 02:26

Today I learned from the museum that in field conditions, soldiers used the steel body of the M1 helmet as makeshift dishware: they boiled water, shaved, washed clothes, etc. The helmet consisted of two parts: a steel outer body and a separate inner plastic or fiber liner (liner), which could be worn separately (for instance, for ceremonies). By the way, it was in military service from the beginning of WWII until the 1980s.

Exploring Farm Freshness: A Visit to an Innovative 24/7 Honor System Store | July 13 2025, 20:39

We stopped by a small farm store on the way. Open 24/7. You grab what you need, money into an envelope, envelope into the slot. Or digitally via QR codes. Bought some soft goat cheese, goat’s milk ice cream, and cucumbers (grown next to the goats). Farm products here are about twice as expensive as store-bought, but they are limited edition, and sometimes unique in the area.