Description
Transcript: At the summer solstice in the northern hemisphere, the northern pole of the Earth is tilted as much towards the Sun as it can. The Sun is overhead at noon at the Tropic of Cancer, the Sun never sets north of the Arctic Circle, and the Sun never rises south of the Antarctic Circle. At winter solstice, December 22, the northern pole of the Earth is tilted as far away from the Sun as it can be. The Sun is overhead at noon at the Tropic of Capricorn, the Sun never sets south of the Antarctic Circe, and the Sun never rises north of the Arctic Circle. The midpoints between the winter and summer solstices are called the equinoxes, spring equinox March 21, fall equinox September 21. At these times, the Sun is overhead at noon the equator and the Sun is just visible at the north and south poles of the Earth’s surface.
Transcript: In the year 584 B.C., on the coast of Asia Minor, two warlike tribes were engaged in a fierce battle: the Medes and the Lydains. As written by the Greek poets, these two cultures were hacking away at each other on the battlefield with burnished swords and shields, when suddenly the...
Published 07/12/11
Transcript: Thales was a philosopher who lived in the 6th century B.C. in Miletus, in what is now Turkey. No written work by Thales survives, but we know that he kept accurate eclipse records and he speculated about astronomy. He decided that the source of all things was one thing, and that...
Published 07/12/11
Transcript: The apparent motions of the stars in the night sky depend on your position on the Earth’s surface. At a northern temperate latitude, the stars rise in the east and set in the west, and they travel on slanting paths across the sky. The north celestial pole sits in the northern sky...
Published 07/12/11