Measuring the Speed of Light with a Coaxial Cable

By Cabell Fisher and Seth Carpenter

January 11-23, 1999

Mission Statement:

           Over the period of two weeks, we were laden with the task of measuring the speed of light with the following equipment:

1. Knowledge of Maxwell's Equations on Electromagnetic Theory
2. A 1000ft (304.8m) RG-58U coaxial cable
3. A Tektronix TDS 320 Digital Oscilloscope with 10x probe
4. A Breadboard supporting a differentiator circuit with a 100 Ohm resistor in parallel with a 100pF capacitor
5. Tektronix Digital a.k.a. "TEKDIG" or DOS program allowing one to capture data points from the TDS 320 Oscilloscope

     The scope of this project entailed deriving a method for calculating the speed of light with a coaxial cable.  We soon found ourselves ensconced, however, in determining the characteristic impedance of our coaxial cable as well as studying the attenuation that occurred with the observed reflected pulses.  Both were integral to the achievement of our overall goal.

Table of Contents:

1. Learn all about coaxial cables and their applications

2. Observe our experimental setup and check out our data

3. View the conclusions that we drew from performing the experiment

Check out Seth Carpenter's Home Page  

Check Out Cabell Fisher's Home Page