Analyse the experimental evidence that supported the models of light that were proposed by Newton and Huygens
Experimental evidence for Newton’s particle model of light :
- In Newton’s model light is composed of particles which travel in a straight line until it hits an obstruction.
- Experimental evidence through reflection of light
- As light particles approach a surface, they rebound after collision by a force at the surface that reverses the normal component of the particle’s velocity, but does not change its tangential component. The particle is then reflected from the surface at an angle equal to its angle of approach.
Experimental evidence for Huygens’ particle model of light :
- Huygens proposed that light is composed of waves. According to his model , every point on the wavefront can be considered to be another source of wave expanding from that point.
- Experimental evidence through refraction of light:
- Huygens was able to predict that refraction happens as light reduces speed in water. This was confirmed by later by Foucault and Fizeau who measured the speed of light in water.
- Experimental evidence through diffraction :
- According to Huygens model, light would have displayed the phenomena of diffraction. This phenomena was experimentally shown by Thomas Young later and confirmed the wave status of light.
Extract from Physics Stage 6 Syllabus © 2017 NSW Education Standards Authority (NESA)