Yesterday was summer equinox. Yes, the 23rd of September and not the 21st as convention taught us in school. To have celebrated the equinox on the 21st would have been similar to celebrating the 4th of July here in these United States on June 30th. It would have been to miss the party altogether.
If you where upon Terra (see Heliotropos), equinox marks the time in which Terra is straight behind the Sun, right at His equator. Half a season to the right of the Sun, the other half to the left. Half a season above the Sun's equator, the other half below. If someone upon Terra were driving a car on a three lane street, equinox could be likened to driving on the center lane behind a truck. Depending on how close or far away this car is from the truck, the driver could either benefit or not from the "quiet zone" made by the truck as it diverts the currents generated by its forward movement.
I find it interesting how the terminology used in the above sentence fits so nicely with this current topic of energy.