Erecting the egg
In China, it is said that the egg can be set upright on the first day of the Start of Spring, Spring Equinox day and Autumn Equinox day. It is believed that if someone can make the egg stand on the first day of Start of Spring, he will have good luck in the future.
According to astronomers and physicists, setting the egg upright has nothing to do with time, but with mechanics. The most important thing is to shift the egg's center of gravity to the lowest part of the egg. In this way, the trick is holding the egg until the yolk sinks as much as possible. For this, people should choose an egg about 4 or 5 days old, whose yolk is inclined to sink down.