Egg balancing at the equinox

While we were at Benita's on Saturday, Pirjo announced that she was going to balance an egg on the table when she got home. She explained that you can only do this at the Spring and Autumn equinoxes. She had read this in a newspaper, and seen it discussed on television. She had tried it in the Spring and it had worked.

It was the final half-price sale at Benita’s so Irma dashed in to buy some eggs.

I looked this up on my phone, and discovered a number of sites, including one called BadAstronomy.com, which described this as an urban myth that refuses to die. Phil Plait at BadAstronomy says that

At any day of the year, grab a carton of eggs and try to stand each one. Usually you cannot stand a raw egg because the inside of an egg is a very viscous (thick) liquid, and the yolk sits in this liquid. The yolk is usually a bit off-center and rides high in the egg, making it very difficult to balance. The egg falls over. However, with patience, you can usually make an egg stand up. It may take a lot of patience!

I discovered that the eggs we had bought stood up quite easily. I have several photos of several different attempts, all of which were successful within a minute or so. This probably says more about the difference between farm eggs and battery hens than between the equinox and any other day.