Final answer:
The Tropic of Cancer and the Tropic of Capricorn correspond to Earth's summer and winter solstices, leading to the start of summer and winter in the Northern and Southern Hemispheres, respectively. They illustrate the effects of Earth's axial tilt on seasonal changes.
Step-by-step explanation:
The Tropic of Cancer and the Tropic of Capricorn are significant in understanding the Earth's solstices and the associated seasons.
The Tropic of Cancer is at 23.5 degrees north latitude and is directly underneath the Sun during the summer solstice in the Northern Hemisphere, usually on June 20 or 21. This marks the beginning of summer in the Northern Hemisphere and winter in the Southern Hemisphere. Conversely, the Tropic of Capricorn, at 23.5 degrees south latitude, is directly beneath the Sun during the winter solstice on December 21 or 22, signaling the start of winter in the Northern Hemisphere and summer in the Southern Hemisphere.
The Earth's axial tilt of approximately 23.5 degrees is responsible for the seasonal changes. In regions above the Tropic of Cancer and below the Tropic of Capricorn, there is significant variation in the intensity and duration of sunlight throughout the year, leading to distinct seasons. In the tropics, however, the sunlight's intensity is more consistent year-round, resulting in less dramatic seasonal changes.