The egg being the most literal and obvious of all fertility symbols, ancient eggish customs survive not only in the form of egg rolling and Easter eggs, but also in the quaint superstitious belief, most often attributed to the Chinese, that you can stand a raw egg on end during the equinox. Apparently this derives from the notion that, due to the sun's equidistant position between the poles of the earth on the first day of spring, special gravitational forces apply.
From a skeptical point of view, the first objection that comes to mind is the fact that there's another equinox on the first day of autumn. Why is there no talk of balancing eggs on end in September? Secondly, while it's true that on both equinoxes the earth's axis is perpendicular to the sun, so day and night are of exactly equal length, there's no scientific reason to suppose that that alignment has any appreciable effect on gravitational forces here on earth. Thirdly, if the equinox can cause this curious anomaly, why aren't there others? Why don't we hear talk of being able to stand broomsticks, pencils, lollipops, or toothpicks on end?