Archive for the ‘Mercury’ Category

Each citizen produces 3.3 tons of e-waste over the course of a lifetime

December 26, 2007

The European Commission estimates that each European citizen produces 3.3 tons of e-waste over the course of an average lifetime, trash that piles up in landfills and leeches toxins into the earth and water. That waste comes from discarded computers, cell-phones, DVD players, toasters, refrigerators, clock radios, medical devices — most everything powered by electricity.

The ingredients used in many of these devices: mercury, cadmium, lead, chromium, and two chemical flame retardants called polybrominated biphenyl flame retardants. These heavy metals and chemicals have been [for years] integral to the circuitry, solder, and casting of thousands of small and large electronic devices.

Studies suggest the ingredients could have potent carcinogenic and endocrine-disrupting effects.

Exposed by Mark Shapiro

Heroic Oversimplification for Modeling our World

October 20, 2007

The invention of deliberately oversimplified theories is one of the major techniques of science, particularly of the “exact” sciences. The biophysicist employs simplified models of the cell, the cosmologist uses simplified models of the universe, and so on.

It may be useful to examine one successful scientific abstraction, to see what it is like and for the sake of the hints it may give us. We choose one which is surely an example of a heroic oversimplification.

Let us assume that we may, in order to study their motions, replace each of the major bodies of the Solar System by a point; that each point experiences a mutual attraction; that we may estimate the attractive force by multiplying the mass of one point by the mass of the other, after which we divide that product by the square of the distance between the points; and that we may neglect all else.

The fact is that this theory, the Theory of Gravitation, has been adequate for predicting the motions of the planets for two and one-half centuries – and this in the face of constant checking by positional astronomers, who, it can fairly be said, carry precision to extremes. The worst strain has come from the orbit of Mercury, which unaccountably drifted from the predicted place by one-fifth of a mil (a foot, at a distance of a mile) per century, thus showing that the theory is rough after all, just as it looks. The improved theory, by Einstein, accounts for this discordance.

The Compleat Strategyst by J.D. Williams