Movement

1. Movement

2. Doppler Effect • the apparent change in wavelength of light that occurs when the object is moving toward or away from the Earth. • Using the spectroscope, astronomers can determine whether a particular object is moving toward Earth or away from Earth

3. Ex) Ambulance Siren: Approach observer: High pitch ; Move away from observer: low pitch

5. Larger Doppler shifts indicate higher speeds and smaller Doppler shifts indicate slower speeds.

6. Big Bang • A theory that explains the origin of the universe • Began as a singularity that started to expand and continues to expand today • Evidence • Red shifts of galaxies • Cosmic Background Radiation (CBR) • Is there an end to the Big Bang? • Big Crunch • Ever-expanding universe

7. Hubble’s Law • States that galaxies are moving away from each other at a speed proportional to their distance from each other • The farther away, the faster they move

8. each raisin will see all other raisins moving away from it as the loaf expands

9. Earth’s Orbit and Seasons

10. Precession • gradual shift in the orientation of Earth's axis of rotation • Cause: the gravitational forces of the Sun and the Moon, and to a lesser extent other bodies • is similar to the precession of a spinning top • Effects: • the positions of the south and north celestial poles appear to move in circles against the space-fixed backdrop of stars • the position of the Earth in its orbit around the Sun at the solstices, equinoxes, or other time defined relative to the seasons, slowly changes http://earthobservatory.nasa.gov/Features/Milankovitch/Images/milankovitch_precess_high.mov

11. Precession

12. Nutation • is a rocking, swaying, or nodding motion in the axis of rotation of a largely axially symmetric object • happens because of tidal forces that cause the precession of the equinoxes to vary over time so that the speed of precession is not constant • principal sources of tidal force are the Sun and Moon, which continuously change location relative to each other and thus cause nutation in Earth's axis

13. Barycenter • refers to the point about which two celestial bodies revolve around • Not usual at the center of an object • Can be outside of the object (sun and Jupiter)

15. Binary Star Systems • There are four ways by which a binary star system can be detected: • visually, and are hence known as visual binaries; • spectroscopically, hence are known as spectroscopic binaries; • photometrically, these are known as eclipsing binaries; and • Astrometrically (wobbly stars), hence are called astrometric binaries