Measuring the velocity of light

Principle

The intensity of the light is modulated and the phase relationship of the transmitter and receiver signal compared. The velocity of light is calculated from the relationship between the changes in the phase and the light path.

Benefits

• Determine yourself what the "speed of light" actually is
• Find out how the velocity of light differs in material
• The size of a table top suffice

Tasks

1. To determine the velocity of light in air.
2. To determine the velocity of light in water and synthetic resin and to calculate the refractive indices.

Learning objectives

• Refractive index
• Wavelength
• Frequency
• Phase
• Modulation
• Electric field constant
• Magnetic field constant