did you know summer comes from a tilt, not a closer Sun?

Earth's axis is tilted about 23.4 degrees from the perpendicular to its orbital plane. as Earth travels around the Sun, each hemisphere takes a turn leaning sunward, changing daylight duration and the angle of incoming sunlight.

when the northern hemisphere tilts towards the Sun, it gets longer days and a higher Sun. the southern hemisphere experiences the opposite. distance from the Sun cannot explain those opposite seasons at the same time.

sunlight striking a surface head-on concentrates its energy. at a shallow angle, the same beam covers more ground. summer combines a more direct Sun with more hours to deliver energy.

the hottest days need not fall at the solstice. land, water, and air store heat, so temperatures often lag behind the peak in incoming sunlight.

for an ideal flat surface, a beam at 60 degrees from the surface normal spreads over twice the area compared with a head-on beam. its power per unit area is halved, before atmospheric effects.

power per area ∝ cos θ; cos 60° = 0.5

• no. distance changes do affect received sunlight, but the axial tilt is the main cause of the familiar opposite seasons.
• near the poles, the tilt can produce entire days without sunset or sunrise. local climate also depends on oceans, winds, and geography.