Today is the spring (or vernal) equinox in the northern hemisphere. This is one of the four transitions — two equinoxes and two solstices — from one season to another: from winter to spring, to summer, to fall (aka autumn), and back to winter.
The reason that earth has seasons is that it is tilted on its axis at an angle of approximately 23.44 degrees (called its obliquity) due to a colossal impact early in its history around 4.5 billion years ago. The hypothesis is that a protoplanet collided with the early earth. This collision caused it to tilt off its perpendicular orientation relative to its orbital plane around the Sun.
During an equinox, the sun rises exactly in the east and sets exactly in the west, and both hemispheres receive almost equal sunlight. The sun is positioned directly above earth’s equator, and the earth is tilted neither toward the sun nor away from it, resulting in nearly equal lengths of day and night across the globe. Continue reading “Equinoxe”

I’ve been spending a great deal of time following the war in the Middle East. It’s depressing as all hell.
Albert Einstein was born on this day, March 14th, in 1879. He will probably be remembered for as long as our present civilization persists. Like all the rest of us, he was a flawed human being. He too was made from the same crooked timber of humanity out of which no straight thing was ever made, as Immanuel Kant so memorably put it in 1784.



