Teaching

Research Faculty Interactions

Fridays, 10:05 - 11:20 a.m., Physics 130

Professor
Hubert Bray
bray@math.duke.edu

189 Physics Building (919)757-8428 (mobile)

Office Hours: Tuesdays and Fridays, 11:20 a.m. - 12:30 p.m.

189 Physics Building (919)757-8428 (mobile)

Office Hours: Tuesdays and Fridays, 11:20 a.m. - 12:30 p.m.

Friday, January 10:

Click here for the pdf notes of the in-class lecture on the sums of powers of the integers.

For Friday, January 17, watch these videos:

2.01 The Kelly Criterion: Triple or Nothing

2.02 The Kelly Criterion: Quadruple or Nothing

2.03 The Gambler's Ruin

Take notes! The quiz on Friday is open notes and can cover anything we've done so far.

For Friday, January 24, watch these videos:

2.04 The Kelly Criterion - The 0-1-2-3 Game

4.01 Intro to General Relativity

4.02 The Geometry of Black Holes

Take notes! The quiz on Friday is open notes and can cover anything we've done so far.

For Friday, January 31, watch these videos:

1.01 Types of Ballots in Elections

1.02 Who Wins a Preferential Ballot Election

1.03 Plurality and Instant Runoff Voting

1.04 The Unit Interval Model

1.05 Instant Runoff Voting is NOT Monotone

Take notes! The quiz on Friday is open notes and can cover anything we've done so far.

For Friday, February 7, watch these videos:

1.06 The Margin of Victory Matrix

1.07 The Borda Count

1.08 The Borda Count is NOT Clone Invariant

1.09 The Borda Count and Nuclear War

1.10 Instant Runoff Borda is Condorcet

1.11 Instant Runoff Borda and the Unit Interval Model

Take notes! The quiz on Friday is open notes and can cover anything we've done so far.

Also, as described in class, survey 15 people on a question with 15 choices, such as "What is your favorite flavor of ice cream?" Print out 16 ballots, with instructions, which people can fill out by putting a 1 by their first choice, a 2 by their second choice, etc., and a 15 by their 15th choice. Fill out a 16th ballot yourself which you will designate the tie breaking ballot. Then go to www.wevotehere.org, click on "Create an Election" and then "Spreadsheet Election" and then follow the instructions. The web page will think for a few minutes and then return a spreadsheet which you can download which tells you which choice won the election, the ranking of all of the choices, as well as many other things about the election.

Turn in THREE things to me by email, by class on Friday: The ballot you created, the spreadsheet produced by the web page, as well as a 1 page summary that you write which includes the question, the 15 choices (in order that they were ranked), and what you found interesting about the results. Put "RFI" in your email subject headline (stands for Research Faculty Interactions) so that I know this is homework you are turning in. Be prepared to discuss your survey in class - I will call on random students.

Also, use this format for the files you turn in by email:

XYZ_Ice Cream Survey_Ballot.docx (or .pdf, or whatever)

XYZ_Ice Cream Survey_Computer Results.xlsx

XYZ_Ice Cream Survey_Summary.docx (or .pdf, or whatever)

where XYZ represent your initials and you put the title of you survey where it says "Ice Cream Survey."

For Friday, February 14, watch these videos:

1.12 The Game Theory of Condorcet Methods

1.13 Worst Defeat

1.14 The Schulze Method

1.15 Ranked Pairs

1.16 Comparison of Vote Counting Methods that use the Margin of Victory Matrix

1.17 What is Democracy?

Take notes! The quiz on Friday is open notes and can cover anything we've done so far.

Friday, February 21: The RFI does not meet because students have a Calculus exam at this time.

For Friday, February 28:

As described in class, survey two different groups of 15 people on a question with 15 chioces. The goal will be to see if the two groups have different opinions on your question and, if so, what those differences are. Discuss whatever you found interesting about the two surveys in one joint summary document. Did you find a Condorcet choice in each survey? Were there cycles in people's preferences? What surprised you or did not surprise you?

Turn in FOUR things to me by email, by class on Friday: The ballot you created, the 2 spreadsheets produced by the web page for each of the 2 surveys, as well as a 1 page summary that you write which includes the question, the 15 choices (in order that they were ranked), and what you found interesting about the results. Put "RFI" in your email subject headline (stands for Research Faculty Interactions) so that I know this is homework you are turning in. Be prepared to discuss your surveys in class - I will call on random students.

Also, use this format for the files you turn in by email:

XYZ_Ice Cream Survey_Ballot.docx (or .pdf, or whatever)

XYZ_Ice Cream Survey_Computer Results for Group 1.xlsx

XYZ_Ice Cream Survey_Computer Results for Group 2.xlsx

XYZ_Ice Cream Survey_Summary.docx (or .pdf, or whatever)

where XYZ represent your initials and you put the title of you survey where it says "Ice Cream Survey."

For Friday, March 6:

Here is a PRACTICE QUIZ. Be sure to work these problems to help prepare for the quiz after watching these videos:

3.01 The Rule of Pythagoras

3.04 Special Relativity is a Minus Sign in the Rule of Pythagoras

3.05 The Light Cone

3.06 The Universality of the Speed of Light

3.07 World Lines and the Twin "Paradox"

3.08 Boosts are Rotations in Space and Time

Take notes! The quiz on Friday is open notes and can cover anything we've done so far.

Friday, March 13: No class - Spring Break

For Friday, March 20: No class - Spring Break (extended because of the coronavirus)

Friday, March 27: The RFI does not meet because students have a Calculus exam at this time.

For Friday, April 3, watch these videos:

3.09 How Velocities Add

3.10 How Velocities Add, Part 2

3.11 How Lengths Contract

After watching the videos, take this QUIZ. The quiz is open notes, open video, and unlimited time. You may discuss the videos with whomever you like up to the point when you look at the quiz, at which time you may not discuss the quiz with anyone else until after you turn the quiz in. When you are done with the quiz, scan and email the quiz to me at bray@math.duke.edu with "RFI" in your email subject headline (stands for Research Faculty Interactions) so that I know this is your quiz that you are turning in.

Watching these videos and taking this quiz will replace our usual class meeting. We will not meet in person or online. Your quiz is due by Friday at 5 p.m. Feel free to turn in the quiz much earlier if you like.

For Friday, April 10:

3.12 The Train in the Tunnel Paradox

3.13 De Sitter Space: The Spacetime Unit Sphere of Special Relativity

3.14 Hyperbolic Space The Spacelike Unit Sphere of Special Relativity

After watching the videos, take this QUIZ. The quiz is open notes, open video, and unlimited time. You may discuss the videos with whomever you like up to the point when you look at the quiz, at which time you may not discuss the quiz with anyone else until after you turn the quiz in. When you are done with the quiz, scan and email the quiz to me at bray@math.duke.edu with "RFI" in your email subject headline (stands for Research Faculty Interactions) so that I know this is your quiz that you are turning in.

Watching these videos and taking this quiz will replace our usual class meeting. We will not meet in person or online. Your quiz is due by Friday at 5 p.m. Feel free to turn in the quiz much earlier if you like.

Friday, April 17: The RFI does not meet because students have a Calculus exam at this time.

Here are some more videos that you might enjoy:

3.02 Rotations and the Dot Product

3.03 Gauss's Geometry and Special Relativity