# Econstudentlog

## Wikipedia articles of interest

“The Bessemer process was the first inexpensive industrial process for the mass-production of steel from molten pig iron. The process is named after its inventor, Henry Bessemer, who took out a patent on the process in 1855. The process was independently discovered in 1851 by William Kelly.[1][2] The process had also been used outside of Europe for hundreds of years, but not on an industrial scale.[3] The key principle is removal of impurities from the iron by oxidation with air being blown through the molten iron. The oxidation also raises the temperature of the iron mass and keeps it molten.”

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“The Bessemer process revolutionized steel manufacture by decreasing its cost, from £40 per long ton to £6-7 per long ton during its introduction, along with greatly increasing the scale and speed of production of this vital raw material. The process also decreased the labor requirements for steel-making. Prior to its introduction, steel was far too expensive to make bridges or the framework for buildings and thus wrought iron had been used throughout the Industrial Revolution. After the introduction of the Bessemer process, steel and wrought iron became similarly priced, and most manufacturers turned to steel. The availability of cheap steel allowed large bridges to be built and enabled the construction of railroads, skyscrapers, and large ships.”

This is so cool! This is just one of the links, here’s another. Imagine how long it would take to get a standard book/paper-encyclopedia published if it were to contain information on this scale. Google earth is not the only thing that revolutionizes our potential knowledge of stuff like this at the moment.

“In mathematics, the harmonic mean (sometimes called the subcontrary mean) is one of several kinds of average. Typically, it is appropriate for situations when the average of rates is desired.”

I’ve omitted the formula because wordpress isn’t a very good tool to use when it comes to mathematical stuff such as this. Go have a look if you’re interested. If you have children that are in school and get math problems about, say, calculating the average speed of a car trip – I know I got that kind of problems back then – which they have trouble solving, this is a good tool to know. Do note that “the arithmetic mean is often mistakenly used in places calling for the harmonic mean.”

4. Battle of Borodino. Why you should know about something like this? Well, it might be useful if you ever get into an argument with coal miners from Llanddarog

5. Hooke’s law.

“In mechanics, and physics, Hooke’s law of elasticity is an approximation that states that the extension of a spring is in direct proportion with the load applied to it. Many materials obey this law as long as the load does not exceed the material’s elastic limit. Materials for which Hooke’s law is a useful approximation are known as linear-elastic or “Hookean” materials. Hooke’s law in simple terms says that strain is directly proportional to stress.”