AS 101
04/10/2012
BRAHE AND KEPLER
LAW OF ELLIPSES
Keplers Law #1 (1609)
Orbits of planets are ellipses with the sun at one focus.
A closed curve with two special points inside called foci.
Special property: the distance from one focus to any point on
AS 101
LECTURE #1
CHAPTER 1
Atoms 4%
Dark Matter 23%
Dark Energy 72%
Note: Dark= not invisible.
Sun
Generates energy through nuclear fusion
300,000 times the mass of earth
Planets
Non luminous and spherical
Orbit around a star
Cleared the neighbourhood of
AS 101
09/10/2012
THE UNIVERSAL THEORY OF GRAVITY
Newton realized that all objects in the universe with mass attract all other objects with
mass
o Mass: the amount of matter in an object (in kg)
o Weight: the force that gravity exerts on an object
Alway
AS 101
11/10/2012
Light is a wavicle
How light behaves depends on how you treat it, it is both wave-like and particle-like
WHAT ARE WAVES?
Waves are any repeating motion that can carry energy without carrying matter along with
it
Wavelength: the dista
AS 101
16/10/2012
MIDTERM
50 multiple choice questions
Lecture notes from Weeks 1-5
Textbook Readings: Ch. 1-3, 4.1, 5.4 (only Doppler effect: p.100-102)
Calculator
EQUATIONS
An equation is concise way to state the relationships between different quan
AS 101
18/10/2012
WHICH PHOTOS EXCITE ELECTRONS?
Photons of the wrong wavelength are transmitted
If the wavelength corresponds to the exact amount of energy needed for a transition, the electron
absorbs photon and becomes (temporarily) excited.
KIRCHOFFS
AS 101
MIDTERM INFORMATION
18/10/2012
Do not need to memorize:
o Dates
o Exact umbers
o Equations
You do need to know:
o Relative sizes and distances (brightest furthest)
o How numbers are used to describe cosmos (powers of 10, magnitude scale,
angles)
o
AS 101
MIDTERM INFORMATION
18/10/2012
Do not need to memorize:
o Dates
o Exact umbers
o Equations
You do need to know:
o Relative sizes and distances (brightest furthest)
o How numbers are used to describe cosmos (powers of 10, magnitude scale,
angles)
o