I have not written anything about the death of iconic physicist Stephen Hawking because there did not seem much that I could add to the massive coverage it received. But throughout his life, there has been one thing that troubled me about the way he was covered and that was how the media dealt with his motor neurone disease. I could not quite put my finger on what bothered me but Ellis Palmer, who also identifies himself as disabled and is a wheelchair user, explains his own unease with how people like him are seen and portrayed.
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When 3D printing came on the scene, I imagined that it would be pretty useful for the custom manufacture of small items. But its applications have gone well beyond my imaginings and the latest example is the ability to build an 650 square foot house in about 12-24 hours for a cost of just $10,000. The people behind it hope to reduce the cost to around $4,000.
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The video below shows what happens when you put a small amount of whipped cream in a vacuum chamber and then suck the air out of it.

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The evolution of mammals that live in the sea (whales, dolphins, and porpoises) are of particular interest because they went from ocean to land and then back to the ocean again. There are many depictions of the first stage but fewer of the second. This animation by artist Jordan Collver shows the second stage of the evolution of the sperm whale, from the amphibious Pakicetus to its present form.
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The winter in Cleveland has been relatively mild so far, and the last two weeks in particular saw warm temperatures and no snow at all. The forecasts seemed to indicate that this would continue but just yesterday the forecast changed suddenly because of the emergence of a storm in the northeast and we had a major snowstorm last night that dumped a large amount of snow on the ground as we slept.
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Last October, I had a post that looked at the units known as the Planck length, Planck time, and Planck mass and discussed the question of whether these were just a universal set of standards that replaced the traditional ones of meter, second, and kilogram or foot, second, and pound, or whether they had a more fundamental significance. I pointed to a paper that suggested that the Planck length might represent a fundamental limit to the continuity of space, that at that level space ceased to be continuously divisible and became like a foam.
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Following the initial Big Bang, the universe was at incredibly high temperatures but then underwent a period of rapid expansion and cooling and largely became a cold gas of hydrogen. The universe could be considered to be dark at this time since there was no source of light. But at some point, matter started to clump together under the force of gravity and form embryonic stars and the hydrogen atoms started to fuse into helium, releasing energy, some of it in the form of visible light. This moment is referred to as the ‘cosmic dawn’ of the universe.
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When we die, it is not like turning off a switch that shuts down everything all at once. Different parts of us fall apart at different times. In the March 2018 issue of Harper’s Magazine, Barbara Ehrenreich describes the process. (Subscription required)
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