Senoufou: Rob, as a schoolteacher all my working life, I can appreciate that when one simplifies a complex and difficult subject, one is presenting a dumbed-down version and inaccuracies may occur. There are simplifications and inaccuracies which inevitably occur when trying to make a specialist subject accessible to a non-specialist audience. However, it should never be the case that the simplification actually introduces completely erroneous ideas. The Cox book I'm thinking of that contained a number of howlers was "Why Does E=mc2?" It has some interesting ways of looking at thing, but quite a lot of what he and his co-author say is just wrong physics. To take one example: "As you relax by a crackling fire you are absorbing heat from the burning coals, and that heat takes energy away from the coal. In the morning, when the fire has died away, you could very carefully sweep up every last piece of ash and weigh it with scales of unfeasible accuracy. Even if you miraculously managed to get every atom of ash, you would find that it weighed less than the original coals weighed. The difference would be equal to the amount of energy liberated divided by the speed of light squared, as predicted by E = mc2, i.e., according to m = E/c2". It is a good thing this isn't true, or you would have been completely incinerated by the fire, along with your house and the whole town that you lived in!!! I can't actually believe he wrote that, the physics is so wrong!
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