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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.