WHY DOES THE SUN APPEAR TO MOVE APPARENTLY FROM TROPIC OF CANCER TO TROPIC OF CANCER AND VICE - VERSA ?
Sun appears to move from tropic of Cancer to the tropic of Capricorn back to the tropic of cancer because earth moves tilted on its axis. Tropic of cancer is the extreme latitude where the sun shines overhead in the northern hemisphere on which the sun shines overhead. As the summer progress in the northern hemisphere the earth tilts towards the sun attains a maximum point in the mid summer (called the summer solstice) this is the tropic of cancer. Beyond this point earth gradually begins to tilt backwards bringing the southern hemisphere closer to the sun. The northern hemisphere gradually recedes away from the sun and southern hemisphere is tilted towards it, this tilt attains its maximum at the winter solstice. That latitude of extreme southern movement of earth is called the tropic of Capricorn. Beyond the winter solstice the northern hemisphere tilts toward the sun and the process is repeated.