Clinging in the Kitchen

We often cover our leftover food with a clear plastic wrap. It’s made from a large molecule called vinylidine chloride. It’s ability to cling to containers depends partly on it’s elasticity. It’s elastic because vinylidine chloride consists of long chains of carbon atoms, which are coiled and kinked like fibres in a piece of wool.…

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Explosives

An important application of chemical energy is the use of explosives.  Any substance that undergoes a very rapid chemical reaction which has a strong heat-liberating quality, or that produces a large volume of gases from a solid or a liquid, is potentially an explosive. The destructive power of an explosion is due to the shock…

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Why Do I Get Hiccups?

The other day I got an attack of hiccups. My grandmother’s cure was to blow into a paper bag. She didn’t know anything about neurological reflexes or phrenic and vagus nerves, which carry the hiccup messages, but her old folk remedy seemed to work. It probably did so by taking advantage of the body’s response…

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Timing A Turkey

These days cooking a turkey requires little skill, because they often come with a handy pop-up timer already inserted in the top. A turkey is finished cooking when the inside temperature reaches about 85 degrees Celsius. That’s the temperature at which the timer pops up to let you know the meat is ready. It’s an…

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The Big Bang

This time, Dr. Humphreys and Ron Hughes discuss the origin of the universe and the implications of the Big Bang theory. Ron Hughes:  David, it seems almost every time you pick up a news magazine, somebody somewhere has made some new discoveries about the origin of the universe or people are working on it feverishly. …

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A Famous Streaker

Long after those physics definitions have faded from memory, we can often recall stories associated with the scientists behind an idea.  For example, many people who can no longer state Archimedes’ Principle formally, (that the ratio of a body’s weight to that of the displaced water is called its specific gravity) still remember that Archimedes…

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Balloons

A balloon filled with any gas which is less dense than air will rise in the atmosphere. This is because the mass of the air displaced by the balloon is greater than the mass of the balloon itself. Since the density of the atmosphere decreases with increasing altitude, the balloon rises until the mass of…

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