There is an old belief that when you smile, your spirits get lifted, as do the spirits of those around you. When you look in a mirror, do you smile? This is not something that people may do consciously and until I saw this video below about the invention of a mirror that shows the image only when people smile, I couldn’t recall whether I usually smiled or not. With this mirror, I would know.
The problem of plastic pollution has come to the fore, thanks to the work of environmental groups who have highlighted the toll it is taking on the oceans and marine life. Much of the damage comes from the sheer volume of plastic items that are used just once and then thrown away. This website by a company called SLOActive that markets sustainable, eco-friendly swimwear has data on the harm that plastics are doing and what we can do to mitigate the damage. The numbers are staggering. About 1.15 to 2.41 million tons of plastic are said to annually enter the world’s oceans via rivers.
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This cartoon is dependent on the idea that early humans died at a very young age compared to now. But Christine Cave says that this is a myth and that people lived to quite old ages.
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‘Evidence-based medicine’ is a term that is now very much in vogue. It suggests that medical practitioners move away from basing their practice on traditions and folklore and instead look to the results of carefully controlled clinical studies for guidance. This is of course good advice. But the problem is determining what makes something ‘evidence-based’. After all, even anecdotes and single events can be considered as evidence since they do provide empirical data. The key question is how to determine when there is a preponderance of evidence that gives confidence that the practice being adopted is the best among all the alternatives. The gold standard consists of carefully controlled, double-blind, reproducible tests with large sample sizes but that is not always feasible and demanding that this be the measure for determining whether a conclusion is evidence-based can be used to delay the adoption of some beneficial measure. It was demands for such unreasonably high standards of evidence that enabled tobacco companies to fight for so long the medical consensus that smoking was highly harmful to human health.
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There was a news item yesterday about the death on a former TV news talk show personality Ed Schultz that said he died at the age of 64 of natural causes. One rarely hears that term used to describe people’s deaths any more. Usually they specify the proximate cause of death (cancer, heart failure, and so on). In the old days, dying from natural causes was the description given for someone who lived to a ripe old age, gradually became more and more infirm as their body started to fail in various ways due to the aging process, and then died more or less peacefully. But what does it mean these days to die of natural causes? After all, Schultz was not particularly old. I became curious as to what the term ‘natural causes’ has come to mean because after all, there has to be some cause.
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As a result of my post on the flat-Earth believers, I was struck by their claim that when you look into the distance, you do not see the Earth’s curvature. This raised in my mind the question of, if you look out over a flat expanse, say a desert or an ocean or from a plane, how far can you see? It may seem as if we can see really far, especially since we can see distant stars, but many factors introduce a great deal of variability.
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Queues are a fact of everyday life and understanding what makes the length of lines vary and how to minimize wait times is of course an important factor for any establishment that has to deal with customers. One of the things that fascinated me in my first statistics course was queuing theory that dealt with this very question. I remember one particular insight. If you look at any train or subway station that has three escalators that carry people between the platform and the street, you will find that it is almost always the case that two of them are going from the platform to the street level and only one the other way. This does not matter if the street level is above or below the platform, nor does it depend on the time of day. The reason is quite simple. People coming to catch a train arrive at random times and thus can be accommodated with a single escalator but when a train arrives at a station, it disgorges a whole bunch of people at once and this requires more exit capability. The 2-1 arrangement is designed to take care of that.
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I have long been curious about what happens to the body when we gain and lose weight. People talk about ‘fat cells’ but I was not clear as to whether we have a relatively fixed number of such cells and weight fluctuations simply consist of the size of these cells changing, or whether the number of cells also changed. David Prologo, a professor of radiology and imaging sciences at Emory University, has a nice article explaining what is going on when we gain and lose weight.
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This nice CGI-aided clip shows how big the rockets that fly into space actually are.
When I was a young boy in Sri Lanka, there was a Jesuit priest-in-training named Basil, a friend of the parents of a friend of mine, who liked to argue with us that the Earth was flat. We of course believed that it was round but as anyone who has argued with a flat-Earther knows, they have quite an array of arguments that they can drop on you to counter your objections and it is a good example of how almost any proposition can be defended if one is allowed to make ad hoc assumptions. We suspected that Basil did not really believe what he was saying but was using the formidable argumentative skills that Jesuits learn to mess with our young minds and show how hard it is to defend even what seem to be obvious truths.
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