Why can the vernal equinox make an egg erect?

On the vernal equinox and solar terms, there is a tradition of setting up eggs in most parts of the country, and the gameplay is very interesting. Do you know why the vernal equinox can make an egg erect?

On the vernal equinox, the northern and southern hemispheres are equally divided day and night, and the earth's axis and the orbital plane around the sun are in a relatively balanced state, and the earth's magnetic field is also relatively balanced. There are many protrusions about 0.03 mm high on the eggshell, and three protrusions form a triangular plane, so that the center of gravity of the egg passes through this plane. Therefore, the vernal equinox is very conducive to spawning, and the success rate of spawning is also relatively high. However, compared with raw eggs, boiled eggs are not easy to stand up. Be careful and patient when laying eggs upright. The less patience you have, the less likely you are to succeed.