Maria Konnikova looked at the research done by anthropologists on the sizes of social groupings. The research initially studied why non-human primates spent so much time on grooming one another but then got extended to humans.

[I]n the nineteen-eighties, the Machiavellian Intelligence Hypothesis (now known as the Social Brain Hypothesis) had just been introduced into anthropological and primatology discourse. It held that primates have large brains because they live in socially complex societies: the larger the group, the larger the brain. Thus, from the size of an animal’s neocortex, the frontal lobe in particular, you could theoretically predict the group size for that animal.

Looking at his grooming data, [anthropologist and psychologist Robin] Dunbar made the mental leap to humans. “We also had humans in our data set so it occurred to me to look to see what size group that relationship might predict for humans,” he told me recently. Dunbar did the math, using a ratio of neocortical volume to total brain volume and mean group size, and came up with a number. Judging from the size of an average human brain, the number of people the average person could have in her social group was a hundred and fifty. Anything beyond that would be too complicated to handle at optimal processing levels.

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Environmental writer Elizabeth Kolbert had an interesting article in the New Yorker about the little-known world of caterpillars and other insects. I have to admit, caterpillars had not figured much in my consciousness but was impressed to learn that they undergo a dizzying array of transformations in their very short lives.

From a caterpillar’s perspective, humans are boring. The young they squeeze out of their bodies are just miniature versions of themselves, with all the limbs and appendages they’ll ever have. As they mature, babies get bigger and stronger and hairier, but that’s about it.

Caterpillars, for their part, are continually reinventing themselves. They emerge from tiny, jewel-like eggs and for their first meal often eat their own egg cases. Once they reach a certain size, they sprout a second head, just behind the first. They then wriggle free of their old skin, the way a diver might wriggle out of a wetsuit. (In the process, the old head drops off.) In the course of their development, they will complete this exercise three, four, in some species sixteen times, often trying out a new look along the way. The spicebush swallowtail, for example, which is found throughout the eastern U.S., emerges from its egg mottled in black and white. This color scheme allows it to pass itself off as a bird dropping. After its third molt, as a so-called fourth instar, it turns green (or brown), with two yellow-and-black spots on its head. The spots, which look uncannily like a pair of eyes, enable the swallowtail to pretend it’s a snake.
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I was talking with someone recently and during the conversation, she started telling me about the psychic she visits who had been very helpful in enabling her to communicate with her dead husband who had given her various kinds of advice. She said that the psychic has also told her many things that were accurate. She also said that on one occasion, she had seen her dead husband in the corner of the room and had made eye contact with him. She said that another person who was with her had also seen her husband.

I got to know this person just within the last couple of years, and while we are not close friends, she is very nice and I like her. While she was telling me this, I simply kept silent, even though I am dyed-in-the-wool materialist who does not believe in the existence of the afterlife and the spirit world. I am also aware that psychics and mediums use cold reading and other methods to give the impression of channeling the voices of dead people. And yet, my friend was so obviously happy with her experience that I did not have the heart to try and disabuse her of her belief.
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Why is he always falling at the same place even though the vehicle is moving ahead? pic.twitter.com/1My2jfynqk

— Domenico (@AvatarDomy) March 15, 2023

It is not a silly question.

The reason is that when we are on a moving vehicle, we have the same velocity as the vehicle and when we jump up, the velocity in that direction does not change and we keep moving in the same direction, with only air resistance to slow us down.

Some time ago, an elementary school teacher in Cleveland asked me a variant of this question. She asked, since the Earth rotates on its axis, instead of flying to California which takes about five hours, we could not just go up in a balloon and wait for three hours so that the Earth’s rotation would bring California to us, saving us time and all that fuel.

Thanks to the internet and the rise of social media, we now live in a world where there are vast numbers of so-called ‘influencers’, people who try to tell others what to do in pretty much every area of their lives, even if they have no expertise or credentials in that field. What is surprising (to me at least) is that there are so many people willing to follow their advice.

Daniel Lemoi was one such influencer and he died on March 3, 2023 at the age of 50. He used his channel on the social media app Telegram to advocate for the use of the drug ivermectin, the deworming medicine that gained popularity as a prophylactic and treatment for Covid. While there is a version of ivermectin that has been developed to treat humans for certain specific ailments, he chose instead to use the version used by vets for large.animals like horses and cows, something that has been strongly discouraged by medical professionals. But its use took off after some people promoted it as an alternative to Covid vaccines and treatments.
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Superconductivity is the phenomenon where the resistance to current flow in a material drops to zero. This means that there will be no loss of energy due to heat generation when current flows through the superconductor. Since resistive heat losses are one of the main limitations associated with any current-generated devices, superconductors open up enormous possibilities for technology that could revolutionize our lives. Unfortunately this phenomenon, first discovered by Heike Kamerlingh Onnes in 1911, only seemed to work at extremely low temperatures close to absolute zero that required cooling with liquid helium, making it impractical for everyday use.

Creating materials that would be superconducting at room temperatures became the Holy Grail of this area of research and a big breakthrough came in 1986 when materials were found that were superconducting at around 90K (-183C) which could be reached using liquid nitrogen. Even higher temperature superconducting materials at about 203K (-77C) have been found but that required enormous pressures, of about 10⁶ times atmospheric pressure.

Recent papers by a research team headed by Ranga Dias and Ahskan Salamat at the University of Rochester have claimed that they have found materials that are superconducting at temperature of 294K (17C) and at a pressure of 10 kbar or ten thousand times the atmospheric pressure. This is big news.
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There has been a lot of buzz in the media about the AI software ChatGPT and its ability to turn out essays that have at least a superficial plausibility. I decided to give it a spin and gave it variations of the same prompt on a topic about which I knew something but was probably too esoteric for non-physicists, just to see what it would come up with.

Here are the prompts and what I got back.

Prompt: Explain Bell’s theorem

Bell’s theorem is a concept in quantum mechanics that describes the phenomenon of entanglement. It states that when two particles are entangled, the properties of one particle are intimately linked to the properties of the other, regardless of the distance between them.

This means that if one particle is measured and its properties are determined, the properties of the other particle are automatically determined as well, even if the two particles are separated by great distances.

Bell’s theorem suggests that this entanglement is not due to some hidden force or connection between the particles, but rather it is a fundamental property of the universe itself. It challenges our everyday understanding of physics and suggests that there are deeper truths waiting to be discovered.

The implications of Bell’s theorem are far-reaching and have been the subject of much research and study in the field of quantum mechanics. It has also led to the development of new technologies, such as quantum computers and quantum cryptography, which rely on the principles of entanglement to function.

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I was forwarded this photograph that purported to show snow in Sri Lanka.

As soon as I saw it I was skeptical. The catch is that Sri Lanka is a tropical island that is just a few degrees north of the equator, somewhat like Hawaii in climate, so snow would be very unusual even given the erratic weather patterns caused by climate change. Furthermore, I lived for many years in the area shown in the photograph and I cannot recall even needing a sweater at any time. It is at an elevation of less than 2,000 ft above sea level.

My initial reaction was that this is one of the many doctored images that float around the internet, especially since there was no sign of snow on the trees or on top of the cars and buildings.

But a friend in Sri Lanka says that while it is not snow, it is not a hoax either, that the material used to resurface the roads results in a soap-like foam emerging after it rains. This apparently happens all over the globe but I have never encountered it myself.

Has anyone observed this?