Physics 1230: Light and Color
Ivan I. Smalyukh, Instructor
Office: Gamow Tower, F-521
Email:
ivan.smalyukh@colorado.edu
Phone: 303-492-7277
Lectures:
Tuesdays & Thursdays,
3:30 PM - 4:45 PM
Office hours:
Mondays & Fridays,
3:30 PM – 4:30 PM
TA: Jhih-An Yang
jhihan.yang@colorado.edu
Introductions
Physics 1230: Light and Color
Day 1:
Why are we here…?
What’s this class about ?
What do we need to do ?
How do we plan on doing it ?
Start learning about light properties.
“Invisible Rod” demonstration
2
Is this possible???
3
http://www.youtube.com/watch?v=JKPVQal851U
http://www.youtube.com/watch?v=JKPVQal851U
Today
•
•
•
•
Introduction
Why the class is as it is
Structure of the class
Lots of information .. Posted on the Web.
– You are responsible for the information on the
website
– Primary resource for class (WILL BE!):
http://www.colorado.edu/physics/phys1230
• First discussion of light properties.
4
Let’s go to the website!
http://www.colorado.edu/physics/phys1230
• How the course works
• Major topics: Homework and exams, your
grade, the book, our first homework on
CULearn, and iClickers.
5
What will be tested in this
class? How can I get a good
grade?
Ability to:
Memorize
"Understand" new
Deeper understanding: Be able to
new facts
concepts at a
figure out new things using concepts
and
mi nim al level
definitions
Percent of grade:
25%
25%
50% (only 15% uses math)
Lecture Notes
• Short and extended
versions of the lecture
notes;
• PPT or PDF files
available for
downloading from the
course web page
7
iClickers
The iClicker is the
University of Colorado
Standard for Clickers.
We will use the iClicker
in most classes.
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Using iClickers
•
•
•
•
•
Everyday: swap clicker code to DC
Wait for 1st clicker question to open
Hold down On/Off Switch 4 seconds
Flashing blue light: hit D C
Type in Answer.
you’re set for rest of class period
• DO NOT TURN OFF CLICKER FOR CLASS
(o.w. repeat above for any new clicker question)
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Example of a clicker question
Do you have your clicker here today?
a) yes
b) no
c) 1492
d) The Gettysburg Address
e) I think so, Brain, but where are we
going to get a trained octopus this time of
night?
10
Have you used clickers
in a prior class?
• A –
• B –
Yes
No
You are NOT locked in to your first choice.
Final answer entered will be
the one accepted/graded.
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Your iClicker
Put your name and contact
information on your clicker
so if you lose it, there is a
chance it will be returned.
You can put your contact
information on a piece of tape
on the clicker if you plan to
return the iClicker in the future
12
Clicker grading
• Performance points for each question
answered
• Additional points for right answer
sometimes
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Survey to be answered by clickers
1. What is your background
for light and color?
Choose the one which
best describes your
science background
a) I have had no physics in
high school or college
b) I have had physics in
high school but not in
college
c) I have taken a physics
course OR a psychology
course at the college
level
d) I have taken more than
one physics or
psychology courses
(high school and/or
college level)
e) I am a science major
Survey to be answered by
clickers
2. Why did you take this
course? Give the
answer which best
describes your reason.
a) Because of
requirements by the
university
b) Because it was
recommended to me
c) Because it looked
easy
d) Because it looked
interesting
e) I don't know why
What is your math background?
a)
b)
c)
d)
Taken up to some level of calculus
Taken up to trigonometry
Taken some algebra.
Something else.
16
The textbook
• Not required but strongly recommended
(HW and reading assignments)
• Not very good, outdated, but there is no
better one;
17
Equations in the course!
• Much more than in “Sound & Music”
• Less than in Graduate quantum
mechanics
• Derivations
• Scientific notations…
•
•
I often hear “I lost my ability to dance”, “Equations are very hard to understand”, “I
cannot sleep…”
I also hear “This is a trivial course,” “I have learned all of this in high school…”
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Scientific notation and metric
system
• Powers of 10 give a
shorthand notation for
very large numbers.
•
•
•
•
103 = 1000
102 = 100
10 1 = 10
100 = 1
• Or very small numbers
• 10-1 = 0.1
• 10-2 = 0.01
• 10-3 = 0.001
• Scientists don't use feet or
miles to indicate distances
• They use
– meters (m)
• 1 meter = 39.4 inches
– kilometers (km)
• 1 km = 1000 m = 0.625 mi
– centimeters (cm)
• 1 cm = 10-2 m = 0.394 inches
– millimeters (mm)
•
1 mm = 10-3 m
– nanometers (nm)
•
1 nm = 10-9 m
Example: dividing numbers in scientific notations
The mathematical description:
Coulomb’s Force Law:
Q
Depends on the
charges
1 qQ
FqQ  r  
rˆ
2
4 0 r
r
distance
q
Constants of
nature.
What is the force that q
feels from Q?
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Another way to think about it:
1 qQ
rˆ
Coulomb’s Force Law: FqQ  r  
2
4 0 r
Which is another way to write this force law?
 1 Q 
A) FqQ  r   q  4 r 2 rˆ 
0


q 1 Q
rˆ
B) FqQ  r   2
2
r 4 0 r
1 qQ
rˆ
C) FqQ  r  
2
4 0 r
D) None of these
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I will help as much as I can
But, if you are taking this course:
• you need to have an appropriate
preparation background;
• You need to be highly motivated and
prepared to work hard;
• May take much more or much less time
than your other courses;
• Might be also easy for you or you might
have learned it already – understand that
others might have a different preparation
22
Physics Helproom!
• Open for questions
• Introduce yourself to neighbors
• A short field trip…to the Physics
Helproom.
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