* Revolution: As the Earth revolves around the sun, the angle at which the sun's rays hit different parts of the Earth changes throughout the year. This is the main reason for the seasons and the varying altitude of the noon sun. During summer, the sun's rays hit the hemisphere tilted towards the sun at a more direct angle, resulting in a higher noon sun altitude. In winter, the hemisphere is tilted away, leading to a lower noon sun altitude.
* Rotation: Earth's rotation on its axis causes day and night, but it doesn't directly affect the noon sun's altitude. While the rotation is responsible for the sun appearing to move across the sky, the altitude change over a year is due to the Earth's position in its orbit.
In summary: Earth's revolution around the sun causes the angle of the sun's rays to change, which in turn affects the noon sun's altitude throughout the year. Earth's rotation causes day and night but doesn't affect the seasonal changes in noon sun altitude.
