
As the days grow longer and the temperatures rise, we enter a seasonal phase I like to call ‘Spring’s Dawn.’
While the cold, wet and dark days of winter still linger, there’s a hint of warmth and sunshine as the coming spring peaks over the horizon.
Up until the north’s Spring Equinox arrives at 8:33 am on Sunday, March 20th of this year, each day grows longer, a few more minutes faster than it did the day before. That’s a bit of a clunky sentence so hopefully, a quick story might help explain the astronomical details.
Think of the seasonal changes as though you were riding on a roller coaster at an amusement park. At the ride’s highest point, the roller coaster slows to a near stop. Think of this as the shortest day of the year – the Winter Solstice—the point where our roller coaster finally loses its battle with gravity. Night comes early, and the dawn is depressingly far away.
The roller coaster then tips over this peak and begins to accelerate as it speeds down to the next low point in the ride – the Summer Solstice. That soul-filling point where the days last forever and, if you live far enough north like I do in Vancouver, Canada, there is no true night. Just a faint blue glow in the northern sky that we call ‘Astronomical Twilight.’
As our roller coaster plummets down to summer, we travel faster and faster. January rushes into March and the days get longer, faster, and faster until, on the spring equinox, the roller coast begins to slow as it approaches the first day of summer, and gravity starts to gives up its chase. As we roll towards summer, the days still get longer but now not by as much as they did yesterday and the day before.
The first of spring – the equinox – the mathematical point of inflection for you fellow math geeks on our planet’s perfectly balanced dance around the Sun.