Finally, the long-awaited first day of spring! The day when the length of day and night are equal and eggs can stand on end, or so they say. The first statement is untrue, and National Geographic tries to explain why (maybe you'll have better luck with it than I did). The second statement is a misleading partial truth, as deconstructed by Snopes.com.
Many, many superstitions involving the breaking, balancing, burying, decorating, reading (for purposes of divination) and hiding of eggs have come to be part of the annual spring celebration. (The linking of egg-balancing with spring celebrations is demonstrated by the fact that the practice is associated only with the vernal equinox, not the autumnal equinox.)Although I'm not sure that will be of much use to Little Oscar, who seems to be pondering deeper, more existential questions.
The Chinese are thought to have originated the practice of standing eggs on end during the equinox. Just as the equinox symbolically restores balance to the world by signalling its rebirth after a season of darkness, the equinox literally balances the day by dividing it into equal portions of darkness and light. If the symbol of fertility — eggs — could be balanced on end during a day equally divided between day and night, this was a sign that all nature was in harmony. That the balancing of eggs could be achieved on any day of the year was of no importance; what everyone wanted and needed was a familiar, reassuring ritual to demonstrate that all was right with the world.