Newton VS Huygen Flashcards
(9 cards)
What is Newton’s corpuscular theory of light?
Newton theorised that light is made up of tiny particles called corpuscles. He used this theory to explain properties like reflection and refraction, although it could not explain diffraction.
How does Newton’s corpuscular theory explain reflection?
When corpuscles strike a surface, a repulsive force acts on them, changing their perpendicular component of velocity (to reverse direction), while the parallel component remains unchanged. This explains how light reflects off surfaces.
How does Newton’s theory explain refraction?
As corpuscles approach a denser medium, attractive forces increase their perpendicular velocity component, while the parallel component remains the same. This causes the light to bend towards the normal. Newton concluded from this that light travels faster in denser media.
Why couldn’t Newton’s theory explain diffraction?
Diffraction involves light bending around obstacles or through small slits, which could not be explained by the particle model of light (corpuscles). This limitation led to the consideration of alternative theories.
What is Huygens’ wave theory of light?
Huygens proposed that light is a wave. According to Huygens’ principle, every point on a wavefront acts as a source of secondary wavelets, which spread out in the forward direction. These wavelets combine to form the next wavefront.
How does Huygens’ principle explain reflection?
Since the wavefront doesn’t reach the surface all at once, wavelets form when parts of it reach the surface. These wavelets then spread out and combine to form the reflected wavefront, consistent with the law of reflection.
How does Huygens’ principle explain refraction?
In a denser medium, it’s assumed that light travels more slowly. So, when a wavefront enters a denser medium, the part that enters first slows down, causing the wavefront to bend towards the normal.
Why was Newton’s theory initially more accepted than Huygens’?
Newton’s theory was favoured because of his high reputation, the lack of experimental evidence for diffraction, and because the speed of light had not yet been measured, making his assumptions harder to challenge at the time.
What is meant by Wave-Particle Duality?
Wave-particle duality is the concept that light and matter (like photons and electrons) can behave both as particles and waves, depending on the situation or experiment.
