Later On

A blog written for those whose interests more or less match mine.

Archive for October 25th, 2020

Man-made whirlpool generates electricity

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Without harm to environment or wildlife.

Written by Leisureguy

25 October 2020 at 6:15 pm

Posted in Daily life, Technology

The illusion of truth

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This video helps explain how President Trump, QAnon, and cults do their work.

Written by Leisureguy

25 October 2020 at 2:19 pm

Posted in GOP, Politics, Religion, Video

Deepest Mandelbrot Set Zoom Animation ever – a New Record! 10^275 (2.1E275 or 2^915)

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The Mandelbrot set has (literally) endless detail as you zoom in for a closer look. The comment on this video posted on YouTube by Orson Wang notes:

Music is “Research Lab” by Dark Flow ( )

Read more geeky details and download the full-resolution video at

Details: The final magnification is 2.1×10^275 (or 2^915). I believe that this is the deepest zoom animation of the Mandelbrot set produced to date (January 2010). Each frame was individually rendered at 640×480 resolution and strung together at 30 frames per second. No frame interpolation was used. All images were lovingly rendered by 12 CPU cores running 24/7 for 6 months. Self-similarity (mini-brots) can be seen at 1:16, 2:30, and at the end 5:00.

Written by Leisureguy

25 October 2020 at 1:43 pm

Posted in Math, Video

Animals Keep Evolving Into Crabs, Which Is Somewhat Disturbing

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Caroline Delbert has an interesting article in Popular Mechanics — to which is appended a very interesting and unrelated video on a inexpensive hydroelectric technology that does not harm to wildlife or the environment.

She writes:

We knew the long quarantine was making us all crabby, but this is extreme: People now feel fully betrayed by the long history of crabification (technically, “carcinization”) of different species over time. That means groups of crustaceans have evolved into crabs in five completely different contexts, giving rise to a meme that the long arc of history truly bends toward the crab.

BoingBoing shares a 2017 paper about carcinization. Carcinization sounds like something about prison at first blush, but on second look, you’ll see it shares a root with carcinogen as well as cancer itself—both from the Greek root karkinos meaning crab. Borradaile coined the new word based on the established scientific usages.

So how does carcinization happen? 

Continue reading — and click the link to see that video, which at the end of the article. — Hah! found the video link, and decided the video deserves its own post.

Written by Leisureguy

25 October 2020 at 1:27 pm

The 48 (!) regular solids

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Well, “solids” is a bit of a misnomer — “polyhedra” is closer (restricting ourselves to three-dimensional Euclidean space. A “solid” to my mind has the characteristic that, if you remove one face and hold the solid with that face uppermost, It will hold water and can be filled. Some of the described polyhedra are not like that.

It’s a mind-stretching but entertaining video.

Written by Leisureguy

25 October 2020 at 1:08 pm

Posted in Math, Video

Animation of a medieval bridge being built

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Consider the Charles Bridge, which crosses the Vltava (Moldau) river in Prague.

Construction began on the famous structure—nearly 1,700 feet (516 meters) long and 33 feet (10 meters) wide—in 1357 under King Charles IV. Forty-five years later, in 1402, the bridge was completed. It was damaged in the Thirty Years’ War, then repaired, damaged in floods in the 15th, 18th, and 19th centuries, and repaired, and updated with more modern appointments over time, such as gaslights. But its bones, as they say, stayed strong.

In the digitally animated video, you can watch the initial construction process in fast-motion–nearly half a century condensed into 3 minutes. Built by architect Peter Parler, it was originally called Stone Bridge. It acquired the king’s name in 1870. “The low-lying medieval structure,” notes Google, who celebrated the 660th anniversary of the bridge in 2017, “is comprised of 16 shallow arches and three Gothic towers, and lined with 30 Baroque-style statues,” added some 200 years ago. Every building has its secrets, and the Charles Bridge no doubt has more than most. One of the first has nothing to do with hidden chambers or buried remains. Rather, “according to legend, during construction, masons added a secret ingredient that they thought would make it stronger: eggs!”

See more animated videos of vintage construction at the Praha Archeologicka channel on YouTube and learn much more about medieval Prague’s many architectural surprises at their site.

This video has a bit more. It’s narrated (in German, I presume), but it allows you to see the actual bridge as well.

Written by Leisureguy

25 October 2020 at 11:48 am

Why do Americans readily accept the widespread use of toxic materials?

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 Pramod Acharya of the Midwest Center for Investigative Reporting comments:

A total of about 400 different agricultural pesticides were used in the United States in 2017, the latest year data is available. More and more pesticides have been used because they “contribute to higher yields and improved product quality by controlling weeds, insects, nematodes, and plant pathogens,” according to the U.S. Department of Agriculture.

However, the USDA noted, pesticides pose consequences for people’s health and the environment.

About 150 agricultural pesticides that the World Health Organization considers “hazardous” at some level to human health were used in the United States in 2017, according to a review of U.S. Geological Survey data

[Read more: EPA takes steps to allow continued use of pesticides linked to cancer, brain development issues in children]

The geological survey estimated that at least one billion pounds of agricultural pesticides were used in 2017. Of that, about 60 percent – or more than 645 million pounds – of the pesticides were hazardous to human health, according to the WHO’s data.

Many “hazardous” pesticides that have been used in the U.S. for decades are banned in many other countries.

[Read more: New pesticide regulations would fix “broken and outdated” system at the EPA, sponsors say]

Twenty-five pesticides that are banned in more than 30 countries were still used in the United States in 2017, according to an analysis of data from the U.S. Geological Survey and the Pesticide Action Network International, which keeps track of banned pesticides around the world. 

The action network’s data show that about 70 of the 150 hazardous pesticides used in the U.S. are banned in at least one country. 

For instance, phorate, the most used “extremely hazardous” insecticide in the U.S. in 2017, is banned in 38 countries, including China, Brazil and India. None of the . . .

Continue reading. There’s more.

Written by Leisureguy

25 October 2020 at 10:16 am

How many dance snippets do you recognize?

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Take a look.

Written by Leisureguy

25 October 2020 at 9:50 am

Brief discussion of Bayes’s Theorem

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Derek Muller notes in his comment on his (interesting) video:

The Bayesian trap is interpreting events that happen repeatedly as events that happen inevitably. They may be inevitable or they may simply be the outcome of a series of steps, which likely depend on our behaviour. Yet our expectation of a certain outcome often leads us to behave just as we always have which only ensures that outcome. To escape the Bayesian trap, we must be willing to experiment.

Written by Leisureguy

25 October 2020 at 8:00 am

Posted in Daily life, Math, Science, Video

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