Understanding the Speed of Light

What was the primary belief about the speed of light before the 17th century?

• It was slower than sound.

• It was faster than sound.

• It was finite.

• It was infinite.

What did Olaf Rømer's observations of Io's eclipses demonstrate?

• Io moves faster than light.

• Light travels instantaneously.

• Light has a finite speed.

• The Earth's orbit is circular.

How did James Bradley contribute to the understanding of light's speed?

• By calculating the Earth's orbit.

• By using a cogwheel experiment.

• By observing stellar parallax.

• By measuring stellar aberration.

What was the key feature of Fizeau's experiment to measure the speed of light?

• A rotating mirror.

• A telescope.

• A prism.

• A cogwheel with 720 teeth.

What improvement did Foucault make to Fizeau's experiment?

• He used a faster cogwheel.

• He used a larger telescope.

• He used a rotating mirror.

• He used a longer path length.

What was the approximate speed of light determined by Fizeau's experiment?

• 313,000 km/s

• 299,792 km/s

• 300,000 km/s

• 212,000 km/s

What was Albert Michelson's contribution to measuring the speed of light?

• He used a cogwheel.

• He improved the optics and baseline.

• He used a rotating mirror.

• He calculated the Earth's orbit.

How is the meter currently defined in relation to the speed of light?

• As the distance light travels in one second.

• As the distance light travels in a vacuum in one hour.

• As the distance light travels in a vacuum in 1/299,792,458 of a second.

• As the distance light travels in a vacuum in one minute.

What did James Maxwell's theory of electromagnetic waves suggest about light?

• Light is a gravitational wave.

• Light is an electromagnetic wave.

• Light is a sound wave.

• Light is a particle.

What was the significance of the experiments conducted in the last 100 years regarding the speed of light?

• They showed light travels slower in a vacuum.

• They improved the precision of the speed of light measurement.

• They proved light is instantaneous.

• They demonstrated light is a particle.