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CORNELL LABORATORY FOR ACCELERATOR-BASED SCIENCES AND EDUCATION — CLASSE

CLASSE NEWS | 10 May 2019

Calculating the Speed of Light

As you know, the speed of light is very, very fast and nothing can go faster than light traveling in a vacuum. People have been measuring the speed of light, or at least trying to, since Galileo’s time in the early 1600’s. Until very recently, the methods have involved ‘time-of-flight’. These are methods that use the distance traveled divided by the time it takes to travel that distance.

CMS participants at Cornell are able to calculate the speed of light for experiments in particle physics, but how do we calculate the speed of light in a high school lab setting? Since light travels so fast, one must either use extremely large measurable distances or find a way to measure extremely short time intervals (or both!).

The CLASSE outreach team has developed a lab experiment in which high schoolers can determine the speed of light by measuring manageable distances right in the lab room, and measuring extremely short time intervals using an oscilloscope. With the help of some of the world's leading researchers here at Cornell, this experiment has been created, explained, and available for schools around the country!