Lecture 15: General Relativity - our Current Best Theory of Gravity
The Equivalence Principle
The acceleration one experiences in a gravitational eld (e.g. things fall to the ground) is in all ways identical (equivalent) to
what one would experience in an
Lecture 3: Motion of the Sun
The Motion of the Sun over one year is shown in the movie. Notice how it moves below the celestial
equator and then above it again. The crossing points are the vernal and autumnal equinoxes, while
the extreme points are the wi
Lecture 9: Newtons Laws of Motion
Sir Isaac Newton
Force and Motion
Contrary to the Greek idea that natural motion meant coming to
rest on Earth and moving in a circle in the heavens, Newton adopted
the notion that natural motion was motion in a
Lecture 1; Denitions, Scale, Error
Solar System: The set of objects gravitationally bound to the Sun. These include the nine planets, their moons, asteroids and comets, as well
as a myriad of small objects - bits of asteroid and comet dust - tha
Lecture 7: Tycho Brahe and Galileo
Naked eye astronomer:
-Achieved positional accuracy of 1/60 of a
degree = 1 arc-minute
-Celestial sphere is not permanent; new
stars (novae) appear and disappear
-Comets are not atmo
Lecture 10: Universal Gravitation
Newton's Theory of Gravity
Gravity is a force, since it makes things fall and they speed up as they fall.
Where does the force come from?.the Earth itself, since that's where all things fall towards.
Lecture 9: Johannes Kepler
Johannes Kepler was born in Weil der Stadt, Germany, where there is a statue and a small museum (in his birth
house) in his honor.
Calculating sidereal period (P) from synodic period (S):
The relationship between Synodic
Lecture 11: Newtons Universe
Calibration of the Gravitational Constant (G) by the Cavendish Experiment -> Mass of the
Earth and other objects.
The concept of parallax, and the distance to Mars by parallax -> calibration of the AU ->
Distance to the planet
Lecture 14: Spacetime
This means three dimensional space and one dimensional time, taken together to locate something. That is, all events occur in space (x,y,z) and time
(t), so they have four "coordinates" that locate them (x,y,z,t). This is s
Lecture 6: Motions of the Planets
Planets (Wanderers) Orbits: Close to ecliptic plane, elliptical orbits
Inferior Planets are Mercury, Venus
Greatest Elongations 28o and 47o
Superior Planets are Mars, Jupiter, Satu
Lecture 23: Interpreting Hubbles Law - General Relativity and the Cosmological Principle
Ways in which the Universe is NOT like a Jamaican Crab Race
- There is no pre-existing empty space into which the race proceeds.
- There is no dead crab at the center
Lecture 27: Atoms, Isotopes, Chemisty and Nuclear Processes
Atomic Nuclei, Elements and Isotopes
Atoms and Molecules
Elements and Isotopes
<- Number of neutrons ->
Lecture 13: Albert Einstein and the Theory of Special Relativity
Postulates of Special Relativity Theory
The theory is based on only two postulates about nature, both of which are supported by all experiments ever done. There are no known
Lecture 29: Big Bang Nucleosynthesis
The more massive a star is, the faster it turns its hydrogen into helium. Therefore, ages of clusters of stars
can be found by determining the mass of the most massive star not yet to have evolved to a red giant.
Lecture 35: The Inationary Universe and String Theory
Tracing the universe back to its rst microsecond
Limits to our Knowledge: Physicists have found that at higher energies (temperatures) the individual forces in nature
unify. A unied theory of the force
Lecture 2: Constellations and Diurnal Motion
This wonderful planetarium software program for displaying the night sky, including motions, etc. is available in the Astronomy Lab. You
will learn how to use it during the lab period next week.
Lecture 4: Precession and the Calendar
What is precession and why does it occur? (See the video)
Polaris has not always been the North Star.
The location of the Vernal Equinox moves along the Ecliptic, making one circuit of the sky in about 26,000 years.