Published: 2017-03-19 23:10:05
Updated: 2017-03-19 23:10:05
Posted March 19
By Tony Rice
On Monday March 20, at 6:28 a.m. EDT, the sun shines directly on the equator. The northern and southern hemispheres will receive roughly equal amounts of sunlight at that instant. Here in the northern hemisphere, it is also known as the vernal or spring equinox.
The sub-solar point, or point on the Earth’s surface where the sun is directly overhead, has been moving northward since the December solstice. On the March equinox, it crosses the equator and continues its northward migration until it reaches the Tropic of Cancer on the June solstice.
You may have heard that you can stand an egg on end at the moment of an equinox, particularly the vernal equinox. The urban legend was popularized by a 1945 Life Magazine article on the subject. It was even featured an episode of the West Wing titled “Evidence of Things Not Seen”.
I’ll save you from getting up early to try this on Monday.
Egg balancing has been associated with Lichun, the beginning of spring in the Chinese calendar. However, Lichun falls on February 3rd or 4th and the equinox falls on March 20. So which day will give you the best chance to balance an egg? It doesn't matter.
If you can perform this balancing act at the equinox, you should be able to perform it any other time of the year, with the right egg and a bit of practice.
Japanese physicist Ukichiro Nakaya found in a 1947 experiment that small bumps and dimples on some egg shells produced tripod-like contact with a flat surface. University of Minnesota astronomer Frank Ghigo replicated the experiment in 1984 saying “It is basically a function of the shape of the egg and the surface.”