Unit Checklist (Print out
in htm or doc)
T / F
| Check
your "Prior Knowledge". |
T/F
|
| Light years measure time. |
. |
| Light years measure distance. |
. |
| Light years measure speed. |
. |
| Light is the only type of energy used to
measure distance. |
. |
| Light years are the best measurement for
every super long distance. |
. |
Pic 1
"A picture is worth a thousand words".
This pic is a clock,
of sorts. Drawing from what you already know, explain what kind
of time is it measuring.
Reading Assignment - TBA
Activities
1. What is a
Light Year?
Read this
article about Light Years and answer the following questions.
a. What is a light year?
b. How fast does light travel in km/s?
c. How fast does light travel in miles/s? (hint: 1 kilometer=.6
miles)
d. In a simple math equation show how a light year is calculated.
(hint: 60 seconds/min, 60 minutes/hour, etc.)
e. Name one unit of space measurement that is less than a light
year?
f. How big is it?
g. Name one unit of space measurement that is more than a light
year?
h. How big is it?
i. How far is the Milky Way in parsecs?
j. How far is the Milky Way in astronomical units?
2. Did
you know?
A light nanosecond -- the distance light can travel in a billionth
of a second -- is about 1 foot (about 30 cm). Radar uses this
fact to measure how far away something like an airplane is.
A radar antenna sends out a short radio pulse and then waits
for it to echo off an airplane or a cloud, tornado, hurricane
or other target. While it's waiting, it counts the number of
nanoseconds that pass. Radio waves travel at the speed of light
so the number of nanoseconds divided by 2 tells the radar unit
how far away the object is! On television weather reports this
is called the Doppler Radar.
a. Picture of the doppler
effect.
3. What
is light?
The light we use to measure time and distance--visible light--is
only one type of electromagnetic radiation. Read the explanation
of the different types of radiation above and below
visible light on the electromagnetic radiation spectrum then
answer the questions.
a. How many types of electromagnetic
radiation exist presently?
b. Where does visible light fall on the spectrum?
c. What type of radiation is immediately above and below visible
light?
d. What type of radiation has the longest wavelength?
e. What type of radiation has the shortest wavelength?
f. How could you limit
what light you see?
g. Can any other type of radiation be used to measure time and
or distance?
h. Try this
site for 3 java applets that show how
light mixes. (Manual options work best.)
i. Here is a java applet on color
seperation.
j. Just for fun, Moire
Images , Thaumatroupes
and optical
illusions.
4. A
Light Tutorial
Light is a tremendously complex topic. For all you ever wanted
to know about light, check out this wonderful explanation. Please
read it and summarize the webpage in your own 250 words.
5. Light
Refraction
Go here
for a cool java applet on light
refraction.
Go here
for a cool java applet on double
refraction.
Not to be confused with light
reflection.
Change angle
of refraction and reflection.
a. Write a definition detailing the difference between reflection
and refraction.
6. Distance
as Time
Read here
and scroll down to "Why are distances important to astronomers"?
7. Rocket
Ships
a. Ever want to travel by rocket? This
is the next best thing. You can see how long it would take to
reach certain points in the universe. Try it for fun!
b. This java applet shows you what it would be like to travel
at an interval of the powers of 10. Take the trip, it is
quite interesting. (They should make a movie of it..."Honey
I shrunk and grew the kids".)
8. Poem
- Read and comment on how light is used in common expression.
Lab - Click here
for Lab activity
T / F
| Now
check "present knowledge" (answers at botom of
page). |
T/F
|
| Light years measure time. |
. |
| Light years measure distance. |
. |
| Light years measure speed. |
. |
| Light is the only type of energy used to
measure distance. |
. |
| Light years are the best measurement for
every super long distance. |
. |
Pic 2
This picture is worth YOUR thousand words
(250 at least).
How is the concept of light an important part of this picture
and the science involved in explaining this picture?
Vocabulary - These
are important terms used in this unit.
By the end of this study you should be familiar with
all of them. Define in writing all the word you don't know.
· Miles
· Kilometers
· Light year
· Astronomical Unit
· Parsec
· Visible Light
· Electromagnetic Spectrum
· Wavelength
· Hubble
· Doppler