“It’s not the heat, it’s the dew point”

We all know that some hot days feel fairly comfortable while others at the same temperature feel clammy and muggy. We tend to identify the difference as caused by the relative humidity and this sentiment is often expressed by the statement “It’s not the heat, it’s the humidity”. But actually, the humidity is not the best measure to use to measure the level of discomfort. A better measure is the lesser-known ‘dew point’. The National Weather Service explains what ‘dew point’ is and why this is the case.
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Lions in India

Until a few months ago, I had thought that lions had always existed only in Africa. But it turns out that not only were lions once roaming parts of Asia, there are Asiatic lions in India even today. Apparently there had once been lions all across the land connections between Africa and India, which makes sense once you think about it since there is no reason why they should have limited their territory unless forced to do so by climate or terrain. This explains why lion metaphors can be found in places like Afghanistan where the political and military leader Ahmad Shah Massoud was called ‘the Lion of Panjshir’.
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Short quiz on evolution

The BBC website has a short quiz consisting of seven true-false questions about evolution that seek to challenge many popular misconceptions. Although I am not a biologist, I do write about evolution from time to time so I took the quiz to see how many misconceptions I had. I got six out of the seven questions right.

But what I want to highlight is the seventh question that I got ‘wrong’. I knew that I would get my response to that one marked wrong even as I answered it. Take a look at the quiz and you will see what I mean.

Fun with numbers!

The integers are one of the most studied areas of mathematics and yet we keep keep learning new things about them. Today comes this bit of knowledge: Any positive integer can be written as the sum of three palindromes. More precisely, this is based on a paper Every Positive Integer Is A Sum Of Three Palindromes by Javier Cilleruelo, Florian Luca, and Lewis Baxter that makes the claim that “For integer g ≥ 5, we prove that any positive integer can be written as a sum of three palindromes in base g.”

Here is an interactive site based on this result. It invites you to write down any number, however large, and then watch as it is given as the sum of three palindromic numbers. Go on, try it!

Numbers are fascinating things. it is not surprising that number theory attracts some of the finest mathematicians.

The myth of scientific manipulation of data

America has this curious strain of anti-intellectualism that sees expert opinion on any topic as somehow suspect. While skepticism is a good quality when practiced in moderation, what Bertrand Russell referred to as ‘heroic skepticism’ that takes a stance in direct opposition to expert opinion, such as that human-caused global warming is not happening and that hence climate change is a fiction, is foolish.
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Rewriting religious anticipations of science history

Nir Shafir is a historian of the early modern Ottoman Empire at the University of California, San Diego. In preparing to teach his class on Science and Islam he was looking at some books and discovered something about the illustrations that seemed a little off.

As I prepared to teach my class ‘Science and Islam’ last spring, I noticed something peculiar about the book I was about to assign to my students. It wasn’t the text – a wonderful translation of a medieval Arabic encyclopaedia – but the cover. Its illustration showed scholars in turbans and medieval Middle Eastern dress, examining the starry sky through telescopes. The miniature purported to be from the premodern Middle East, but something was off.

Besides the colours being a bit too vivid, and the brushstrokes a little too clean, what perturbed me were the telescopes. The telescope was known in the Middle East after Galileo invented it in the 17th century, but almost no illustrations or miniatures ever depicted such an object. When I tracked down the full image, two more figures emerged: one also looking through a telescope, while the other jotted down notes while his hand spun a globe – another instrument that was rarely drawn. The starkest contradiction, however, was the quill in the fourth figure’s hand. Middle Eastern scholars had always used reed pens to write. By now there was no denying it: the cover illustration was a modern-day forgery, masquerading as a medieval illustration.

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Henrietta Swan Leavitt: An ignored and forgotten scientist

In recent times, there has been greater awareness of the major but overlooked contributions that women have played in the sciences, and attempts to lift them out of the obscurity to which they had been consigned. The recent film Hidden Figures told of the women mathematicians, African-American women in particular, who worked in the US space program in the 1960s doing critical complex calculations despite the Jim Crow laws that heaped all manner of indignities on them.
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Big step towards open-access science publishing

When it comes to science, the coin of the realm, the measure by which ideas and scientists are evaluated, is by being published in peer-reviewed journals. The journals are run either by professional organizations of scientists as a non-profit arm, such as all the journals run by the American Institute of Physics or the American Physical Society or are purely commercial private operations, such as the prestigious journal Nature. Journals subscriptions are then sold to individuals and libraries. But over time, a combination of rapidly rising subscription costs, shrinking library budgets, and the rise of the internet has created both a crisis and an opportunity for radical changes.
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Myths about human sperm

I suppose I am like most people who have a model of conception as a great race, involving a male emitting a vast number of sperm that then race towards the egg waiting for them in the female and one of the sperm, the victor, gets to fertilize the egg. Robert D. Martin, emeritus curator of biological anthropology at the Field Museum in Chicago and a member of the Committee on Evolutionary Biology at the University of Chicago, writes about the history of studies into sperm and that this idea of ‘macho sperm’ is one of the many myths that surround conception.
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The environmental impact of animal farming

Two arguments are advanced in favor of veganism and vegetarianism. One is the moral one, that the animals we eat are sentient beings that are similar to humans and that it is wrong for us to kill and eat them, even if we eliminate the cruelty of factory farming. The second is an economic and environmental argument, that animals are a highly inefficient source of protein, requiring the expenditure of a vast amount of resources. The rough rule of thumb is that as we go up the food chain, we lose 90% of the energy at each stage. In other words, by feeding grain to animals for the meat, we get only 10% of the energy that was initially stored in the grain. If the animals are fed a diet of animal protein, then we lose another 90%, leaving us with only 1% of the initial energy. This is highly wasteful.
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