Recreate the historical experiment that demonstrated the fundamental concept that led to transmitting light through optical fiber. In 1870, before the skeptical British Royal Society, Irish researcher John Tyndall successfully demonstrated how light could be guided in a stream of falling water. It was the first recorded observation of light being guided by "total internal reflection," and it still is a visually fascinating experiment today. Using modern components, demonstrate this basic principle of light's behavior when it enters a constricting optical channel.

Set-up for each experiment requires less than five minutes and costs only a few pennies. ("Just add water!")

A visible-light laser with optical power of .5 mW or greater is required for use, but not included.