Berkeley: Latitude: 37º 9′ North Longitude: 122º 2′ West
The Tilt: The 23.5º tilt of the earth, combined with the earth’s yearly orbit around the sun, are what cause our seasons. The northern hemisphere is tilted toward the sun in summer (the growing season) and away from the sun in our winter. The axis of the earth is always tilted directly to the north star.
Tilt In Winter
Graphic illustrates solar energy being concentrated on the southern hemisphere
Solar Noon: At solar noon, when the sun is at its highest point in the sky for that season, shadows from the sun are aligned with the longitudinal meridian of Berkeley (122.2º W). The shadows are long on the winter solstice (75º) and short on the summer solstice (29º), and midway on the equinoxes (52º). Ancient peoples have long used shadows to determine season, find geographical direction, and to align buildings.
Earth In Motion: At our latitude, 37.9º N, the sun appears low in the sky in winter (29º) and high in the sky in summer (75º). However, contrary to what we see with our eyes, i.e., the sun’s apparent movement across the sky, it is the earth that is in motion. It is ROTATING on its axis and cycling between day and night every 24 hours, and orbiting around the sun on its 365 day yearly journey. And that is what makes us have seasons.