TED-Ed: Is light a particle or a wave? - Colm Kelleher

The video explores the evolution of our understanding of light and vision, starting with ancient Greek theories that light originated from the eyes. Alhazen corrected this by showing that light is collected by the eyes. Newton proposed that light is made of particles, but later experiments revealed light's wave properties, such as interference patterns. The 20th century introduced quantum mechanics, showing light's dual nature as both wave and particle, leading to a deeper understanding of phenomena like color and energy transfer.

What was the main flaw in the ancient Greek theory of light?

• It proposed that light is made of waves.

• It couldn't explain why it gets dark sometimes.

• It suggested that light originated from the sun.

• It couldn't explain why objects emit light.

What did Isaac Newton believe about the nature of light?

• Light is a wave.

• Light is a reflection of the sun.

• Light is made of tiny particles called corpuscles.

• Light is a form of energy.

Which phenomenon demonstrates that light behaves like a wave?

• Reflection

• Refraction

• Interference patterns

• Absorption

What did 20th-century experiments reveal about light?

• Light behaves like both a particle and a wave.

• Light is only a particle.

• Light is only a wave.

• Light is neither a particle nor a wave.

What is the significance of quantum mechanics in understanding light?

• It shows that light is a form of energy.

• It proves that light is made of atoms.

• It explains why light is only a wave.

• It describes how light can behave as both a particle and a wave.