Balance an Egg on the Equinox

Saturday, March 20, 2010 is the vernal equinox, which marks the first day of spring in the northern hemisphere. Are you familiar with the urban legend that it's easier to balance an egg on end on the equinox than on other days of the year? Test it and see! This vernal equinox one of the two times during the year when the sun crosses the celestial equator and the spin axis of the Earth points 90 degrees away from the sun. Why should this affect your ability to balance an egg on end? The premise is that aligning the gravitational pull of the Sun with that from the center of the Earth should somehow make it easier to balance any object.




Test the Hypothesis Yourself



Take a carton of eggs and try balancing the eggs on end today. Can you stand any of them up (without resorting to tricks like putting salt under the eggs)? Can you stand eggs on their small ends as well as their large ends? Keep track of your results and repeat the process on the equinox. Do you note any differences? A simple hypothesis to test is: Eggs can only be balanced on-end on the equinox. If you can balance an egg today, you've disproven the hypothesis. It's that easy!



One thing I find neat about egg-balancing is that a balanced egg will hold its position until a vibration knocks it down. How long can you keep an egg standing?