A new low in US anti-vaccine misinformation

A private school in Florida (of course!) is actually barring vaccinated teachers from interacting with students. The school fees are pretty high which shows that this school caters to the high income and high wealth population.

A Miami school has discouraged teachers from getting the Covid vaccine, saying any vaccinated employees will be barred from interacting with students.

Centner Academy leadership cited debunked claims of non-vaccinated people being “negatively impacted” by contact with vaccinated people.
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Perceptions of time

I have long been interested in how we perceive time. There are many markers of time’s passage, daily and seasonal changes and biological changes being just some of them. Albert Einstein revolutionized our understanding of time by saying that physical time of an event is what is given by clocks placed at the location of the event, and then showed that the interval in clock readings between any two events depended on the state of motion of the clocks.

But there is also the psychological perception of time, the sense of how much time has elapsed when one has no external means such as a clock or diurnal rhythms to keep track of it. In an experiment, 15 volunteers were kept in a deep cave for 40 days without any means of knowing the passage of time other than their sense of it.
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The problem with cryptocurrencies

I know almost nothing about cryptocurrencies or the blockchain technology that undergirds it. I was aware that all transactions by currency holders are recorded on a distributed public ledger, which apparently is what is meant by a ‘blockchain’. I had been aware that these currencies, of which there are many in addition to the best known one of bitcoin, are not backed by any government like ‘real’ currencies are. Their value is maintained by having their production limited by having it ‘mined’, which is a metaphor for actions that are done by computers.

Elizabeth Kolbert writes about how this ‘mining’ works.
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The pandemic and hygiene habits

I have been seeing a lot of stories such as this one about how staying at home and social isolation has resulted in some people changing their personal hygiene habits, sometimes entirely jettisoning some of them.

Working from home, shielding, not socialising or just losing the will to blow-dry appear to have had many of us questioning whether our pre-pandemic personal hygiene and grooming habits were really necessary. And, with routines disrupted, it is perfectly possible to get to the end of the day before wondering if you have brushed your teeth. Or putting off your morning shower until you have done some lunchtime exercise, and then not bothering to do that either.

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The US should send its excess vaccines to countries that need them

Vaccination rates in the US are slowing down as the people who want to take it have increasingly done so, leaving mostly the so-called vaccine-hesitant and the vaccine deniers. The US is reaching a point where there are excess stocks of unused vaccines.

The United States could have around 300 million excess Covid-19 shots by the end of July, health policy experts at Duke University estimated in a report Thursday, calling on the country to share doses more widely to address the stark inequality around global vaccine distribution.
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The problem of changing scientific conclusions

People tend to like certainty. One of the things that people get wrong about science is that they think it should provide them with that certainty. But scientific conclusions, while they tend to be the most reliable that we have at any given time, can change in the light of new evidence which is why results are usually phrased conditionally. Unfortunately that nuance is often missing when the media reports science results and this can be disconcerting for some people when new results seem to contradict the old. I deal with this question quite extensively in my book The Great Paradox of Science.
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Creating a more accurate flat map of the Earth

Projecting the surface of a globe on to a flat surface always introduces distortions. Richard Gott, Dave Goldberg, and Bob Vanderbei claim to have created created a projection that minimizes the errors more than any projection before.

Previously, Goldberg and I identified six critical error types a flat map can have: local shapes, areas, distances, flexion (bending), skewness (lopsidedness) and boundary cuts. These are illustrated by the famous Mercator projection, the base template for Google maps. It has perfect local shapes but is bad at depicting areas. Greenland appears as large as South America even though it covers only one seventh the area on the globe.
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How many T. Rex dinosaurs have ever lived?

The headline that 2.5 billon T. Rex dinosaurs walked the Earth was definitely something that caught my attention. It turns out that that number was just the average with a massive variation in possible values. What I was more interested in was how one sets about even making an estimate of the number of animals in a species that has been extinct for 65 million years. The paper lays out the problem and basic method they used.

Although much can be deduced from fossils alone, estimating abundance and preservation rates of extinct species requires data from living species. Here, we use the relationship between population density and body mass among living species combined with our substantial knowledge of Tyrannosaurus rex to calculate population variables and preservation rates for postjuvenile T. rex. We estimate that its abundance at any one time was ~20,000 individuals, that it persisted for ~127,000 generations, and that the total number of T. rex that ever lived was ~2.5 billion individuals, with a fossil recovery rate of 1 per ~80 million individuals or 1 per 16,000 individuals where its fossils are most abundant. The uncertainties in these values span more than two orders of magnitude, largely because of the variance in the density–body mass relationship rather than variance in the paleobiological input variables.

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