Using ‘evidence-based science’ as a weapon against progress

‘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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How we describe people’s deaths

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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How far can you see?

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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Why buses bunch up

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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How fat cells work

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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What drives the ‘Flat Earth’ belief?

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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The Stanford prison experiment is not what it seemed

Many of you will have heard of the famous Stanford prison experiment in 1971 when Philip Zimbardo, a psychology professor at Stanford University, randomly assigned one group of students to be inmates and the other group to be guards who had total power over the prisoners for two weeks. The setting was a mock prison (actually the basement of a university building). But after six days the experiment had to be called off because, as claimed by Zimbardo, the ‘guards’ used such sadistic methods against the ‘inmates’ that the latter were on the verge of breakdowns. The experiment has been cited numerous times to warn of the dangers of giving people unchecked power over others and the need for prison reform.
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How a child can have DNA from three people

Jennifer Barfield, a professor of assisted reproductive technologies at Colorado State University, clearly explains how it can come about and what led to the development of the technology that has made it possible. The key point is that in addition to the DNA that comes from the father and the mother, the fertilized egg also contains mitochondrial DNA (mtDNA) that plays a vital role in producing energy.
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