P Technology Enabled Active Learning (TEAL) Learning without Barriers / Technology without Borders Symposium December 2, 2006 John Belcher, Peter Dourmashkin Physics Department MIT Creative Commons Attribution-Share Alike 2.5 License

P Learning Objectives of TEAL Create an engaging and technologically enabled active learning environment Move away from passive lecture/recitation format Incorporate hands-on experiments Enhance conceptual understanding Enhance problem-solving ability

P Broader Educational Learning Objectives Develop communication skills in core sciences Develop collaborative learning Create an environment conducive to learning and teaching Develop new teaching/learning resources

P Desktop Experiments Put lecture demos into students hands Groups of three students take data in class using LabView software. Introduction to experimentation Integration of concepts and experience Graphical representation of physics concepts

P Website web.mit.edu/8.01t/www web.mit.edu/8.02t/www

P A Sample 8.02 TEAL Class

P Thanks to the MIT first year students in 8.02 this term who are joining us today: Nicole Bieber Christopher Cosmides Mark Barineau Neeharika Bhartiya

P Class 31: Outline Wednesday Nov 29, 2006 Hour 1: Generating Electromagnetic Waves Plane EM Waves Electric Dipole EM Waves Hour 2: Experiment 8: Microwaves generated by the spark gap antenna

P Clicker Question: Your E&M Background

P My Last Course in E&M Was In 1.High School 2.College 3.Grad School 4.Never had one

P Clicker Question: Baseline E&M Knowledge

P The earth’s magnetic field in this room is: 1.Mostly vertical and pointing down 2.Mostly horizontal and pointing north 3.Mostly vertical and pointing up 4.Mostly horizontal and pointing south

P The earth’s magnetic field in this room is: 1.Mostly vertical and pointing downward 2.Mostly horizontal and pointing north 3.Mostly vertical and pointing upward 4.Mostly horizontal and pointing south

P Answer: 1. The earth’s magnetic field in this room is mostly vertical and pointing downward

P Clicker Question: Sophisticated E&M Knowledge

P As we move our receiving antenna around the spark gap antenna as shown, we see 1.More power at A 2.More power at B 3.Same power at A & B 4.Do not know

P Review: Electromagnetic Radiation

P Recall Electromagnetic Radiation: Plane Waves

P Properties of EM Waves Travel (through vacuum) with speed of light At every point in the wave and any instant of time, E and B are in phase with one another, with E and B fields perpendicular to one another, and to the direction of propagation (they are transverse):

P How Do You Generate Plane Electromagnetic Radiation?

P Shake a Sheet of Charge Link

P ) If sheet position is What is B(x,t)? What is E(x,t)? What Direction? Group Problem: B Field Generation Sheet (blue) has uniform charge density  Starting time T ago pulled down at velocity v 1) What is B field? (HINT: Change drawing perspective) sheet

P Plane waves are simple but not what we usually see How Do You Generate What We Usually See: Electric Dipole Electromagnetic Waves?

P Generating Electric Dipole Radiation Applet

P How Do You Shake a Charge? Spark Gap Antenna

P Spark Gap Antenna

P Clicker Question: Sophisticated E&M Knowledge

P As we move our receiving antenna around the spark gap antenna as shown, we see 1.More power at A 2.More power at B 3.Same power at A & B 4.Do not know

P Answer: 2. Maximum power at A. The electric field pattern from the spark gap antenna is shown. We get maximum power when the line from the transmitter to the receiver is perpendicular to the direction of the antenna (at A). We get (in principle) zero power when the line from the transmitter to the receiver lies along the direction of the antenna (at B).

P Experiment 8 Spark Gap Generator: An LC Oscillator

P Our spark gap antenna 1) Charge gap (RC) 2) Breakdown! (LC) 3) Repeat

P Spark Gap Antenna

P Spark Gap Antenna

P What Lies Ahead Focus on teacher training Continued development of Teaching/Learning resources Introduction of new communication devices into classroom Refine experiments with a shift towards Inquiry- Based experiments Development of tabletop demos Publication of MIT 8.01/8.02 Course Notes