FALL: By the time you read this, the autumnal equinox will have occurred.
It was at 3:50 a.m. today.
Today, fall begins in the northern hemisphere, while spring begins in the southern hemisphere.
The Old Farmer’s Almanac tells us the word “equinox” comes from Latin “aequus,” meaning equal, and “nox” meaning night. On the equinox, day and night are roughly equal in terms of length.
“During the equinox, the Sun crosses what we call the ‘celestial equator’ — an imaginary extension into space of Earth’s equator line. The equinox occurs precisely when the Sun’s center passes through this line. When the Sun crosses the equator from north to south, this marks the autumnal equinox; when it crosses from south to north, this marks the vernal equinox.
After the autumnal equinox, the sun is rising later and nightfall comes sooner. This ends with the December solstice, when days start to grow longer and nights shorter.”
The day and night are not strictly equal, but at the autumnal equinox, “the Earth will angle perfectly sideways to the Sun. Neither pole will tip toward or away from it,” the almanac says.
“A more precise equinox event is that the Sun rises and sets exactly in the east and west, not southeast or northwest or anything else. It’s a time of precision, and an opportunity to correctly position your sundial, that task you keep putting off.”
Also today, the sun moves in a “laser-straight line across the sky. By comparison, for the past six months, the Sun’s path has displayed an upward curve, concave to the north, like a giant smile. Starting right after the equinox, the Sun’s track across the sky starts to bend like a rainbow, with the concave part aimed downward.”
The almanac cleared up an old wives’ tale about a balancing egg, too.
“As for the age-old idea that eggs are able to balance on end during the equinox but at no other time — that’s just silly. Why should the laws of gravity be repealed just because the Sun illuminates both poles equally that day? Still, it’s fun to consider, especially if it sparks conversation about the reasons for the seasons.”
