Answers to all homework questions will be posted on the class website
First exam: Monday, October 3.
If the wavelength of an electromagnetic wave increases, its velocity
(red) Decreases
(yellow) Increases
(blue) Remains the same
(green) Not enough information
If the wavelength of an electromagnetic wave increases, its velocity
(red) Decreases
(yellow) Increases
(blue) Remains the same
(green) Not enough information
If the wavelength of an electromagnetic wave increases, its frequency
(red) Decreases
(yellow) Increases
(blue) Remains the same
(green) Not enough information
If the wavelength of an electromagnetic wave increases, its frequency
(red) Decreases
(yellow) Increases
(blue) Remains the same
(green) Not enough information
If the wavelength of an electromagnetic wave increases, its energy
(red) Decreases
(yellow) Increases
(blue) Remains the same
(green) Not enough information
If the wavelength of an electromagnetic wave increases, its energy
(red) Decreases
(yellow) Increases
(blue) Remains the same
(green) Not enough information
You are an astronaut taking a spacewalk to fix your spacecraft with a hammer. Your lifeline breaks and the jets on your back pack are out of fuel. To return safely to your spacecraft (without the help of someone else), you should
a) throw the hammer at the space ship to get someone's attention. b) throw the hammer away from the space ship. c) use a swimming motion with your arms. d) kiss your ship good bye.
You are an astronaut taking a spacewalk to fix your spacecraft with a hammer. Your lifeline breaks and the jets on your back pack are out of fuel. To return safely to your spacecraft (without the help of someone else), you should
a) throw the hammer at the space ship to get someone's attention. b) throw the hammer away from the space ship. c) use a swimming motion with your arms. d) kiss your ship good bye.
The Doppler Shift:
A shift in wavelength due to a wave emitter moving towards (shorter wavelength) or away (longer wavelength) from an observer.
v c
=
The Doppler Effect
1. Light emitted from an object moving towards you will have its wavelength shortened.
2. Light emitted from an object moving away from you will have its wavelength lengthened.
3. Light emitted from an object moving perpendicular to your line-of-sight will not change its wavelength.
BLUESHIFTBLUESHIFT
REDSHIFTREDSHIFT
Measuring Radial Velocity● We can measure the Doppler
shift of emission or absorption lines in the spectrum of an astronomical object.
● We can then calculate the velocity of the object in the direction either towards or away from Earth. (radial velocity)
v c
=
In conducting a search for life, we must understand how planets are formed and what determines their habitability.
What does any theory of the formation and evolution of the solar
System have to account for,
i.e., what are the “observed facts”?
The Sun:
A central star
Predominately H and He
Most of the mass in the solar system.
Rotates in same sense that planets
orbit.
Size: small large Location: closer to Sun more
distant Composition: rocky/metallic gaseous/icy Temperature: hotter colder Rings: none ubiquitous Rotation rate: slow rapid Surface: solid not solid Atmosphere: minimal
substantial Moons: few to none many
Terrestrial Planets Jovian Planets
Planetary orbits:
1) Prograde
2) approximately coplanar
3) approximately circular
Rotation:
1) Mostly Prograde
2) Includes sun
3) Includes large moons
There are large numbers of smaller objects in the Solar System
moons: both rocky & icy asteroids: rocky comets: icy
small
Rocky
Odd-shapes
nearly circular orbits
orbit planes are near Ecliptic Plane
orbits in inner part of solar system
Asteroids
small nucleus
“dirty snow ball”
very large tails
highly eccentric orbits
all orbit inclinations
Comets