No evidence that Planck graininess slows down light

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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Shaolin monk pierces glass with a needle

The Shaolin order of monks in China is noted for its rigorous training that enables them to perform quite incredible feats of strength and endurance. They are also known for being fierce kung fu warriors, strange for Buddhist monks who are supposed to be pacifist. So how did that happen? Kallie Szczepanski provides a brief summary of the turbulent 1,500 year old history of the order that mixes legend with facts.
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The dawn of the universe

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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Doing the right thing for the wrong reasons

I am back from my travels and was greeted with the news that Donald Trump seems to have backed off his earlier support for the anti-vaccination movement. At various points, he had expressed support for widely debunked claims that vaccines could cause autism and had even proposed setting up a commission to ‘study’ the issue, which many people feared would provide a highly visible platform for the skeptics to spread their ideas.
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The Havana mystery

There was a story that appeared in the news some time ago about a mysterious sound that was supposedly affecting US embassy personnel in Havana and creating such debilitating effects that it resulted in some of them deciding to come back to the US. There were allegations that Cuba was waging some kind of high-tech warfare against the US but the case for that was pretty thin, even allowing for the fact that there would be no motive for them to do so, since they are interested in improving ties with the US.
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The impact of Deep Learning on our lives

The last meeting of Science Café Cleveland had as its presenter Wyatt Newman, a professor at Case Western Reserve University, who gave a fascinating presentation on the state of Deep Learning, the term given by the Artificial Intelligence community to the next stage of AI development, where machines learn to identify things and make decisions for novel situations that they have not been previously programed to deal with. It is this feature, for example, that enables self-driving vehicles to identify the various things it encounters on roads and take appropriate actions.
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The alcohol problem

I do not drink alcohol, except for the occasional champagne or wine at weddings and other social events when such beverages are used to toast people. But I grew up in a family where most of the men drank a lot and Sri Lanka has a lot of heavy drinkers so I am familiar with the problems that alcohol can cause. Given that environment, why I did not start drinking myself I do not know. Perhaps seeing the adverse ways it caused people to behave was one factor. Another may be that my group of friends in college, the age when most people pick up the habit, were not drinkers either and so it was not part of our group activities and there was no peer pressure. Alcohol was not cheap and we preferred to spend our money on films and food. It was only much later that I learned of the genetic element that predisposes some people to become alcoholics and so it is perhaps a good thing that I did not start, just in case I had the gene and it may have been triggered.
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