Astronomy

The main reasons that mathematicians studied astronomy was to solve problems dealing with

• the calendar (such as determining the seasons)
• predictions of eclipses
• finding the beginning of the lunar month

In studying astronomy, the mathematics  of Greece created a plane and spherical trigonometry and developed a mathematical model of the universe.

Some terms:
Celestial equator- the axis of which the daily rotation of teh celestial sphere takes place.

vernal and autumnal equinoxes- the points of which the equator and ecliptic intersects one another

The 7 wanderers- They participated in the daily east to west rotation of the celestial sphere but also had their own motions. The 7 wanderers were the sun, the moon, Mercury, Venus, Mars Jupiter, and Saturn.

Great Circle-  A section of a sphere by a lane trough its center. For example the equator is one great circle. The earth has infinitely many great circles.

• The ecliptic, is a great circle that passes through the 12 constellations of the zodiac.

The major contributors to mathematical astronomy were

1. Eudoxus
2. Apollonius
3. Hipparchus
4. Menelaus
5. Ptolemy

Eudoxus was responsible for turning astronomy into mathematical science and is accredited with the invention of the two sphere model. He regarded the models as computational devices.

Hipparchus (190-120) began calculating trigonometric ratios. He also did numerous observations of planetary positions. For his trigonometry, he used chords subtending an arc or central angle in a circle with a fixed radius

Unanswered Question

1. Where there any other attempts to created a spherical model of the Universe? If so, how did they explain the heaven's movement? How did it fail?

Evalueation:
Quality: 8
Complexity: 7
Interesting: 7