An earlier reply in the 5 July issue regarding the weight of an MP3 player is misleading, although I agree with the conclusion. It implies that data bits are stored by adding or removing electrons from a memory cell, and that these electrons are supplied by a battery. In fact, bits are stored by moving electrons from one part of the memory cell to another, so there is no net gain or loss of electrons in the memory chip. The chip contains the same number of electrons, and thus weighs the same, whether it's all Os, all 1s or full of data.
展开▼
