Today I Learned

It's considered invasive in Indian and Pacific Ocean islands, and is native to the United States. Much to my surprise, there's no mention of Australia!

Be safe out there 💀🗡️🐌

I saw this article at BoingBoing, and had to look it up.

From Wikipedia:

The Aroma of Tacoma, also known as the Tacoma Aroma, is a putrid and unpleasant odor associated with Tacoma, Washington, United States.[1] The smell has been described as similar to the odor of rotten eggs.[2] The odor is not noticeable throughout the city, but is rather concentrated in the Tacoma tideflats and is frequently smelled by motorists traveling that section of Interstate 5.[2]

https://en.wikipedia.org/wiki/Bicolored-spined_porcupine

cross-posted from: https://lemmy.world/post/49317483

So i'm doing a bit of reading about the basics of nuclear fission these days, just to understand what's actually happening there.

Here are some interesting things that i think that i learned so far:³

• nuclear engineering is all about the neutron economy. If you had an easily-available cheap source of neutrons, we wouldn't need big nuclear power plants because energy could be easily generated by hitting Hydrogen-1 (protium) with neutrons to make H-2 (deuterium) out of it. According to this diagram, this releases around 2 MeV of energy per collision (resulting nucleus has 2 nucleons), which is a lot of energy.

• the problem is that we don't have a cheap source of neutrons, and that's about where the whole trouble with nuclear energy begins. we're smashing U-235 specifically because it's fissile and can sustain a chain reaction: It emits more neutrons per collision than it absorbs, so we get a net gain of neutrons out of it.

• the sun sources its neutrons from weak interaction between protons and electrons¹. Basically this fuses a proton and an electron together to make a neutron. This is the rate-limiting factor in the sun's fusion and determines the sun's lifetime before it burns through its fuel. The average time for a particle to undergo weak interaction is about 10¹⁰ years in the sun's interior which is about the sun's lifetime. If the sun had more neutrons, it would burn faster.²

[1]: well, sorta. this is kinda simplified and more precisely described in the proton-proton chain which is the same thing but with extra frills.

[2]: Also note that while the weak interaction is the rate-limiting factor of the fusion process, it barely releases any energy. Almost all of the energy is released due to the strong interaction which glues protons and neutrons together really tightly and that way releases a lot of energy.

[3]: if you know better, please do correct me.

In economics, hedonic regression, also sometimes called hedonic demand theory, is a revealed preference method for estimating demand or value of a characteristic of a differentiated good. It decomposes the item being researched into its constituent characteristics and obtains estimates of the contributory value for each. This requires that the composite good (the item being researched and valued) can be reduced to its constituent parts and that those resulting parts are in some way valued by the market. Hedonic models are most commonly estimated using regression analysis, although some more generalized models such as sales adjustment grids are special cases which do not.

Chimaeras are cartilaginous fish in the order Chimaeriformes (/kɪˈmɛrɪfɔːrmiːz/), known informally as ghost sharks, rat fish (not to be confused with rattails), spookfish, or rabbit fish

https://www.cnbc.com/2025/12/04/microsoft-will-raise-prices-of-commercial-office-bundles-in-july-.html

The term bourgeois originated in medieval France, where it denoted an inhabitant of a walled town. Its overtones became important in the 18th century, when the middle class of professionals, manufacturers, and their literary and political allies began to demand an influence in politics consistent with their economic status. Marx was one of many thinkers who treated the French Revolution as a revolution of the bourgeois.

Source: Britannica

I was in an art gallery and so confused about the use of the term with respect to art contemporary to the French Revolution. So I looked it up lol

The find was made by William Buckland, Oxford University's first Reader in Geology. The presence of the beads and other ornaments led him to conclude that the bones were of a woman, and the find quickly became known as the 'Red Lady of Paviland'. Buckland also assumed that the 'Red Lady' was from the Roman period, around 2,000 years ago. We now know that they are the remains of a young man, and far more ancient.

In 2008, scientists used improved radiocarbon-dating techniques, which showed that the bones are around 33–34,000 years old (from a less cold episode during the last glaciation), making the 'Red Lady' one of the oldest examples of a ceremonial burial in Western Europe. Stone tools and burned animal bones show that he could have been one of the hunters that used the cave over many thousands of years. How he died remains a mystery, but the evidence indicates that he was buried ceremonially.

Scientists are looking to extract DNA from one of the leg bones to find out more about who he was and where he came from.

Happy Canada Day!

Bonus! Canada is also the first country to issue painted coins for circulation.

https://en.wikipedia.org/wiki/Pontic%E2%80%93Caspian_steppe

it's a rather interesting area. going by this world map, it's rather flat and fertile. might be an early civilization hub in human history.