The reason hard boiled eggs dont last as long as raw eggs is that in cooking the eggs, a natural protective chemical layer (produced by the mother hen) is washed off the porous eggshell, allowing germs to enter. Source(s): http://cookery.newarchaeology.com/how_lo... sugarice82 Â· 9 years ago.
Freebase(0.00 / 0 votes)Rate this definition: Song cycle. A song cycle is a group of songs designed to be performed in a sequence as a single entity. As a rule, all of the songs are by the same composer and often use words from the same poet or lyricist.
Population cycle. A population cycle in zoology is a phenomenon where populations rise and fall over a predictable period of time. There are some species where population numbers have reasonably predictable patterns of change although the full reasons for population cycles is one of the major unsolved ecological problems. There are a number of factors which influence population change such as availability of food, predators, diseases and climate.