If you think about it, there seems to be no good reason for packaging eggs with their wide end up as opposed to plunking them into the cartons wide-end down: either way will keep the egg from rolling off. Yet cardboard cartons and the plastic egg-tray in refrigerators are made to accommodate a fat-end-up egg. Is there something more here than just coincidence?
In fact, there is: the reason it's smarter to store your eggs with the fat end up is that the egg itself does not
completely fill the interior of the shell. If you crack open a hard-boiled egg carefully at the fat end, you will see that the white part of the egg, called the albumen, does not quite reach the shell -- there's a pocket of air in-between the two. That isn't the case for the narrow end of the egg, which fits snugly. That pocket of air allows for the presence, and reproduction, of bacteria. This is not to say there'...
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