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2 Individual Quanta of Energy

reference they have produced all the technology we find around us today, technology which includes both minute electronic transactions between atoms and vast nuclear explosions of almost unlimited extent. The users of the energy systems surrounding us know that a battery is used to make computer chips function and that they must buy a new one after a while because they run down. They also know that they must plug in their shaver or toaster or refrigerator to get it to function for the purpose for which it was created. The complexity of thinking required here is caused by our having to consider energy systems of various scales as having two possible states — isolated or connected — and these as functioning differently according to whether there is energy flowing into the system in both states, or only when connected. In 1905 Einstein made physicists consider that matter was energy. This was a breakthrough in our thinking because matter and energy struck physicists' minds as well as their instruments in such different ways that they could not conceive of both as one. For Einstein and all physicists since, the principle of conservation of mass (postulated by Lavoisier around 1780) became a special case of the principle of conservation of energy (postulated by J. R. Mayer and by Joule around 1840). Because any mass (in grams) is quantitatively a certain amount of energy (in ergs) divided by the square of the speed of light (in CGS units), the only change available in the cosmic universe is from energy to matter and from matter to energy (in its form of


On Death  
On Death  

"Is there any hope that we may ever know what death is? Since it is a problem of knowing, we need to find the epistemological devices that w...