Category Archives: Science And Society

Mathematics, Media Criticism, Science And Society, Space, Technology and Society

Nuclear Weapons As A Unit Of Measurement

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Some thoughts:

“In general,” he added, “What I don’t like is … the idea that kiloton or a megaton is just an energy unit, that it’s equivalent to so many joules or something. Because you could do that. You could claim that your house runs so many tons of TNT worth of electricity per year, but it sort of trivializes the notion.”

While I agree that the notion of comparing a bolide explosion to a nuclear event is misleading, I think he misses the boat himself here. It’s not just about an “energy release.” It’s about how fast the energy is released. That is, talking about megatons of TNT is a discussion about power, not energy per se. This is the same confusion that people have with regard to rocketry. They often talk about how much “energy” it takes to get into orbit, when in fact it’s not much more energy than it takes for intercontinental aircraft flight. The difference is that the airplane deploys its energy over many hours, whereas the rocket must do so in a very few minutes. When the Shuttle took off, it generated more power than the entire nation’s electrical grid for the first two minutes. In fact, when I was working propulsion at Rotary Rocket in the nineties, we used to joke about what units we should use to describe the power output of the engine, and thought that “Hoovers” (as in the dam) would be a useful one.

In any event, radiation and heat or no, either exploding meteoroids or nuclear weapons city busters, and events to be concerned about.

Business, Culinary, Health, Media Criticism, Political Commentary, Science And Society, Social Commentary

A Calorie

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…is not a calorie:

“Our current system for assessing calories is surely wrong,” said evolutionary biologist Richard Wrangham of Harvard University, the co-organizer of the panel.

In a wide-ranging discussion of how food is digested in everything from humans to rats to pythons, the panel reviewed a new spate of studies showing that foods are processed differently as they move from our gullet to our guts and beyond. They agreed that net caloric counts for many foods are flawed because they don’t take into account the energy used to digest food; the bite that oral and gut bacteria take out of various foods; or the properties of different foods themselves that speed up or slow down their journey through the intestines, such as whether they are cooked or resistant to digestion.

Of course, in addition to that, the thermodynamic theory of nutrition doesn’t take into account how your metabolism responds to different kinds of calories. In a just world, much of the lipophobic nutrition industry would be sued into oblivion, or in prison, bearing responsibility for millions of premature deaths, and sufferers of ill health. Instead, they still seem to be in charge of the FDA.