Monthly Archives: March 2009


‘And the light shone in the darkness and the darkness comprehended it not..’ Due to its high reactivity, phosphorus is never found as a free element in nature on Earth. The first form of phosphorus to be discovered (white phosphorus, discovered in … Continue reading

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Diffraction – wave spreading around an edge

The wavelength of water waves may be several metres. If the wavelength is of a similar size to a gap in a harbour wall, then the wave will diffract  or spread out into circular ripples. This is quite a good aerial image which shows the effect clearly.  If the wavelength  is much smaller than … Continue reading

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Latin “frango,” = I break, as in fracture. The straws look broken as we view them through the water. The light from them is being refracted, changing direction and travelling more slowly in the water than the air around it. … Continue reading

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All waves bounce off surfaces. Water waves hit walls and bounce off them, light hits mirrors and bounces off and so on. We can imagine the direction of the wave travel to be a streak, drawn as a straight line … Continue reading

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Hydrogen as a Fuel

  One day, the oil will run out, so we’d better have a few ideas ready so we needn’t go back to camels and bicycles for transportation. Under the hood will shortly look something like this…. The idea of a … Continue reading

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Waves Basics

There are two types of wave motion, transverse where the oscillation direction is at 90 degrees to the travel, and longitudinal where the oscillation and travel directions are along the same straight line. Light is transverse, sound is longitudinal. Earthquake … Continue reading

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