“A Message from the Future”

Naomi Klein introduces a powerful seven-minute video daring us to imagine how the Green New Deal can take us to a future much better than the one we are currently on a path towards.

TODAY, THE INTERCEPT launches “A Message From the Future With Alexandria Ocasio-Cortez,” a seven-minute film narrated by the congresswoman and illustrated by Molly Crabapple. Set a couple of decades from now, it’s a flat-out rejection of the idea that a dystopian future is a forgone conclusion. Instead, it offers a thought experiment: What if we decided not to drive off the climate cliff? What if we chose to radically change course and save both our habitat and ourselves?

The problem with counting calories

I have a friend who is a dedicated calorie counter. In order to control her weight, she carefully notes the calorie value of all the food she eats and the amount of exercise she needs to take to burn it off. If she indulges in an extra treat, she will note it and compensate by working out more the next day, according to a formula that relates the type and duration of exercise to the amount of calories that need to be burned. This requires a lot of bookkeeping but she is a very organized person.
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Dilbert does not understand random sampling

Cartoonist Scott Adams, creator of the comic strip Dilbert, is a climate change skeptic who repeats the well-worn anti-science tropes of that community. Usually he attacks the credibility of the climate change models that are used to predict the scale of climate change and the potential consequences. But in this cartoon, he goes further and seems to be attacking the whole idea of random statistical sampling.
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The size of the photographed black hole event horizon

Obtaining the first-ever photograph of a black hole was an impressive feat. We tend to think of black holes as being tiny and they are. A black hole represents a singularity in space-time where gravitational field becomes so large that there is extreme curvature of space. But the ‘event horizon’ of a black hole, the region inside from which no light can escape, need not be tiny. It is the event horizon that gives rise to the dark region seen in the photograph and the size of the event horizon for any mass M is given by the Schwarzschild radius that is equal to 2GM/c2, where G is the gravitational constant and c is the speed of light.

The black hole at the center of the galaxy M87 that was photographed has a mass 6.5 billion times the mass of the Sun and thus its Schwarzschild radius is about 1.9×1010 km. This is quite large, about three times the distance of the planet Pluto from the Sun, which is 5.9×109 km.

How technology can improve without increased understanding

Archeologists sometimes find ancient artifacts that show considerable sophistication. These might cause us to infer that the people of that time had a better understanding of the underlying science than we had previously given them credit for. This is because advances in technology often go hand in hand with advances in science. Technological advances upon up new frontiers for scientific investigation while new scientific theories lead to new technologies. But that link may not always exist.
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Jet lag asymmetry

I do not suffer from jet lag that much but I have friends who suffer terribly. I ascribe my greater tolerance to my belief that a prime cause is tiredness during the long flight and so make it a point to sleep as much as possible on the plane, which I am fortunately able to do. Some people find it very hard to sleep and watch a lot of inflight films which may make the even more tired. I have also experienced that traveling west is easier than traveling east and I put that down to the fact that going west results in the day-night cycle becoming stretched out and so one has longer nights and can more sleep.
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Calls to end use of statistical significance

There has long been a common method used in science and social sciences when deciding whether results are worth publishing. One starts out with what is called the ‘null hypothesis’, a kind of baseline that might represent (say) the current conventional wisdom, and then one sees if the results of the experiment are consistent with it. If it is not consistent, then the results are considered to be more interesting than if they were. This requires the use of statistics and then one has the problem of deciding whether the result is a real effect or a statistical anomaly. For a long time, something called the ‘p-value’ was used to make this decision and a p-value of 0.05 was used as the benchmark for statistical significance.
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A new stage in whale evolution discovered

The evolution of whales is one of the most fascinating stories in evolution because it goes in the opposite direction to the conventional story, of a land animal becoming a water-based one. The outlines of this have been pretty well established but now comes a report of the discovery of a new fossil of a large whale with four large legs that showed it to be capable of life on land and sea.

Photograph: A. Gennari/CellPress

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The color of prehistoric animals

We often see artistic representations of animals that have long been extinct. Some of these are in color, even though we only have the fossils. Fossil expert Maria McNamara explains how scientists try to infer their coloration. She says that they carefully study fossil metallic insects with hard shells that have preserved their color as fossils to see what makes them take on various colors. She says that if an animal’s skin layer is fossilized, that helps too. When it comes to dinosaur colors, she says:
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Brexit memes and physics

A lot of memes have been circulating drawing parallels with the awkward Brexit attempts by the British government, such as this one.

I chose this one to highlight because the person seems to have a common misunderstanding that Galileo tried to clear up a long time ago about the nature of relative motion. Since the man was on the train, he had the same velocity as the train when he jumped off and hence was moving in the direction of the tracks when he hit the ground. It was not allowing for that that caused him to fall. If he had jumped more along the direction of the train’s motion and with a running action in that direction, it would have been much less jarring to him and may have managed to stay upright.

Not that I am recommending anything that dangerous of course!