An 'Egg-xaggerated' tale: You can stand up an egg on the equinox!
There has been a long-time wives tale that you can stand up an egg on the equinoxes. The legend appears to stem from some sort of "seasonal gravity." Unlike Dec. 21 when the Earth's tilt has us pointed away from the sun, and June 21 is when we're tilted the most toward the sun, the equinox dates are when we're exactly in between, and the Earth's tilt is at a 90 degree angle with respect to the sun's light.
Some felt that meant the Earth's tilt is zero then, and so with the Earth pointing straight up, that eggs will stand up and not be pulled over by the tilt.
But it's all gibberish. Actually, the Earth's tilt doesn't move at all -- at least not noticeably. The seasons occur because of Earth's tilt relative to the sun as we orbit around, but our planet spins on the same axis year 'round, so even if the Earth's tilt affected gravity, nothing would change between each day. (Now, over thousands of years, we do wobble a bit, but that's another story...)
No, what really matters is nothing more than making sure you have a flat surface and an egg that has formed evenly. So, the long and short of it is, you can stand the right egg up on its side no matter what day of the year it is.
Want proof? Check out this photo, courtesy of the excellent Bad Astronomy website by Phil Plait who defies all logic by standing up several eggs -- in the middle of October!
He even has done a video on how you can stand up an egg, no matter the date:
Feel free to go try and stand an egg up now -- just be sure to clean up the mess if it rolls off the table.