2014

Welcome to Advanced Physics Lab 2014!

Instructors

Professor: Tobias Marriage (marriage@pha.jhu.edu), Office: Bloomberg 215

TAs: Ian Anderson (ianderso@pha.jhu.edu), Office: Bloomberg 429

Lab Guru: Steve Wonnell (wonnell@pha.jhu.edu), Office: Bloomberg 478

Wiki

This page (https://wiki.pha.jhu.edu/advlab_wiki/index.php/2014) is your source of much course-related knowledge. Useful materials will be distributed here.

Also check out general descriptions of labs and pages for previous years at

https://wiki.pha.jhu.edu/advlab_wiki/index.php

General Description

In this class, you you'll learn

• how to conduct an experiment, collecting data with special attention to estimating systematic and statistical measurement errors,
• how to model the data,
• and how to present your work through scientific writing.

These three aspects essentially define the course. Each lab will be evaluated based on how well the three aspects are realized.

Classes

Times: Monday 10:00-12:50 and 1:30-4:30

Classes will run in a seminar format. They will begin with a lecture, sometimes involving computing/laptop participation, followed by discussion and short updates on experimental work from students. A shared online directory (Google drive) will be used to upload update material.

At the beginning of a new experiment, an introduction to the new experiment will also be given in the class.

Experiments

While much effort will be spent with data analysis and scientific writing, the exciting centerpiece of the course is executing four advanced experiments. You'll have a generous three weeks to work on each experiment. The first experiment will start in the second week of the course. The planned experiments we will work through are the following.

1. Brownian Motion: The goal of this experiment is to estimate the Boltzmann constant using a measurement of the brownian motion of microscopic spheres.
2. Speed of Light: In this experiment you use the classic Foucault spinning mirror measurement to estimate the speed of light.
3. Single Photon Interference: This experiment explores the interference of quantum wave functions.
4. Radio Astronomy: In this experiment you'll use a 1.4 GHz (21 cm) radio telescope to look out into the galaxy and (possibly) beyond.

The first two experiments are intended to be a good match to the beginning data analysis being taught in lectures and readings during the first half of the course. These should help you ramp up in terms of your familiarity with data and errors. They are also very cool measurements of two of the most important numbers in physics!

The second two experiments, to be completed in the second half of the semester, are intended to be matched to the more advanced material presented in lectures and readings during the second half of the course. These are new experiments that we've developed over the last two years and think are particularly exciting.

Location and Access

The all experiments associated with the lab are located in room 478 of Bloomberg Hall: the Physics Undergraduate Computer (PUC) lab. Access to the lab is managed by Steve Wonnell (wonnell@pha.jhu.edu). A PUCLab login for the computers will also be useful. Steve Wonnell is also the person to contact for this.

Safety

Use your common sense in all situations. In these labs you'll encounter lasers (where appropriate goggles) and other manageable hazards. Follow the safety instructions at all times. Food and drink are not allowed near the labs. Safety also follows from orderliness: please keep the lab in a tidy state. When in doubt: ask the professor, Steve Wonnell or the TA.

Readings

I will lecture weekly from the classic Bevington text, which is mainly on data analysis. In principle you can work from lecture notes, but you will get more out of the class if you read the text and take your own notes as well.

Bevington & Robinson, Data Reduction and Error Analysis for the Physical Sciences, 3rd Edition, McGraw-Hill, ISBN 0-07-247227-8, 2003

I will have a couple class copies that you can read in the lab. (Please keep these in the PUCLab!)

Schedule

Below is the nominal schedule for the course.

Date	Lecture	Weekly Reading	Other Notes
Jan 27	Class Overview, Measurement & Errors	Bev. Ch1	Work on basic LaTeX and Python examples
Class material to go here.
Feb 03	Probability Distributions, Exp. 1 Introduction	Bev. Ch 2	Start Exp. 1
Feb 10	Propagation of Errors	Bev. Ch 3	Updates on Exp. 1
Feb 17	Estimates of Mean and Errors	Bev. Ch 4	Updates on Exp. 1; Exp. 1 Report Draft Due
Feb 24	Monte Carlo Techniques	Bev. Ch 5	Exp. 1 Report Due, Start Exp. 2
Mar 3	Linear Least Squares 1	Bev. Ch 6	Updates on Exp. 2
Mar 10	Linear Least Squares 2	Bev. Ch 7	Updates on Exp. 2
Mar 17-21 Spring Break
Mar 24	Nonlinear Fitting 1	Bev. Ch 8	Exp. 2 Due, Start Exp. 3
Mar 31	Nonlinear Fitting 2	Bev. Ch 9	Updates on Exp. 3
Apr 7	Maximum Likelihood	Bev. Ch 10	Updates on Exp. 3
Apr 14	Testing the Fit	Bev. Ch 11	Exp. 3 Due, Start Exp. 4
Apr 21	TBD	-	Updates on Exp. 4
Apr 28	TBD	-	Updates on Exp. 4

Groups and Scheduling

You should team up into lab groups of two or three for executing the experiments. It's probably best to have one group through all labs, so you become used to working with one another and fall into a schedule. It would be good to form these in the first week.

While the first lab has multiple stations, the following labs have one apparatus. Therefore groups will need to schedule times throughout week when they will be using the instrument. We will set up a scheduling system (likely Google calendar or spreadsheet). Groups may "team up" if necessary to collect data together, but preferably it can be done group by group. In any case, just make sure everyone gets to take some data! And also be friendly and considerate when sharing the equipment.

Other Useful Texts

Data Analysis

• Press, Teukolsky, Vetterling, Flannery, Numerical Recipes in C (Available online)
• Lupton, "Statistics in Theory and Practice"

LaTeX

• Lamport, LaTeX: A Document Preparation System
• A Not Too Short Introduction to LaTeX: media:not_too_short.pdf

You might also find useful websites from previous years.