Module 7 (Light wave model) Flashcards
Isaac Newton proposed a wave model, what was the bases of it.
Isaac Newton’s model of light, known as the corpuscular theory, proposed that light is made of tiny particles called “corpuscles.”
What experiments supported Newtons theory?
Reflection: Newton proposed that light particles, or corpuscles, bounce off surfaces the same angle it hit.
Refraction: He suggested that when light corpuscles pass from one medium to another (e.g air to water), their speed changes, causing a change in direction. This explained the bending of light when it enters a different medium.
Why couldn’t Newton’s corpuscular theory explain the diffraction of light?
Newton’s corpuscular theory, which treated light as particles, couldn’t explain diffraction because it couldn’t account for light bending around obstacles and creating interference patterns.
Why did the double-slit experiment challenge Newton’s corpuscular theory of light?
Conducted by Thomas Young, showed that light creates an interference pattern of bright and dark fringes. This wave interference could not be explained by Newton’s corpuscular theory, which treated light as particles that would not produce such a pattern. The experiment provided strong evidence for the wave nature of light.
What is Huygens’ theory of light?
Huygens’ theory of light, also known as the wave theory, proposes that light behaves as a wave. According to this theory, each point on a light wavefront acts as a source of secondary spherical wavelets. The new wavefront is formed by the envelope of these wavelets.
Describe Reflection
Reflection was explained by analogising a light particle with a particle such as a ball bearing
undergoing an elastic, frictionless collision against a smooth surface, which would preserve the angle of
incidence towards the normal of the surface when being bounced off with an angle of reflection.
Describe Newton’s Corpuscular Theory of Light
Sir Isaac Newton, in the late 17th century, proposed the Corpuscular Theory of Light. He suggested that light consists of tiny particles called corpuscles, which travel in straight lines and are emitted by light sources. This model explained reflection and refraction, but it could not account for phenomena like diffraction and interference.
Describe Huygens’ Wave Theory of Light
Christiaan Huygens, a contemporary of Newton, proposed an alternative model known as the Wave Theory of Light. According to this theory, light behaves as a series of waves that propagate through a medium called the ether. Huygens’ Wave Theory could explain not only reflection and refraction but also diffraction and interference. However, this model struggled to explain the photoelectric effect and other phenomena that would later be discovered.
Define and describe Polarisation
Polarisation is the process of restricting the oscillation of the electric field of light to a single direction. Light is a transverse wave, with electric and magnetic fields oscillating perpendicular to its direction of travel. In unpolarised light, these fields can oscillate in any direction perpendicular to the propagation. Polarisation limits this oscillation to one plane.
