Keplers Laws
First Law:
1609
The planetary orbits are elliptical, with the Sun at one focus
Second Law:
1609
A imaginary line connecting the Sun to any planet sweeps out equal areas
in equal times
Third Law:
1619
The square of a planets orbital peri

Gravity
Due to the:
curvature of space-time
Scientific Method
human endeavor
whims of culture
personality
religion
The Scientific Method:
always guides us towards an objective description of our world
takes hundreds of years to make progress
Radiation:

Newton & Kepler
Johannes Kepler:
1600
pure theorist
initially believed planetary orbits were related to perfect geometry
nested solids
nested solids idea didnt match up with data
used triangulation to determine the shapes of the orbits
required determin

Isaac Newton
Isaac Newton:
1643-1727
born the year Galileo died
explained the elliptical orbits
research from Kepler
discovered the Law of Gravitation
1665
developed the Laws of Mechanics
govern all motions
invented calculus
1665
solve mathematical p

Radiation Spectrum
different objects can be brighter at different frequencies
wavelengths
shape of the radiation spectrum is usually related to the temperature of the
object
Black-Body Radiation:
spectrum emitted from a body by virtue of its temperature i

Doppler Effect
observed wavelength of radiation depends on the speed of the source relative
to the observer
called the Doppler Effect
a stationary observer see the wavelength of the light
color
Doppler Effect:
an observer moving away from the source see

Stefans Law
the total energy radiated at all frequencies of the Planck curve is given by
Stefans Law
4 F = T
where is Stefans constant
F is the flux
energy per second per square cm
hotter objects radiate much more energy than cooler objects
a star wit

Photoelectric Effect
quantization of radiation energy
Albert Einstein
explains the photoelectric effect
for red light:
no electrons are ejected from the metal plate
for blue light:
slow electrons are ejected
for ultraviolet (UV) light:
fast electr

Newtons Laws of Motion
First Law:
Every body continues in a state of rest or uniform motion unless acted on
by an outside force
Second Law:
When a force F is applied to a mass M, the resulting acceleration A is
related to F by
A is directly proportional

Radiation
information remains intact when
light doesnt run into something along the way
the Earth is not special
Copernican hypothesis
hypothesize that the physical laws we observe on Earth operate
in the same way everywhere
Radiation:
from such a big