Evaluating the Models of Light: Particle Model vs. Wave Model

Comprehensive vocabulary flashcards reviewing Newton's Particle Model and Huygens' Wave Model of light across optical phenomena including rectilinear propagation, reflection, refraction, dispersion, diffraction, partial reflection/refraction, and speed of light.

Particle Model of Light

The model proposed by Newton stating that light is composed of particles that travel at high speeds in straight lines and experience attraction toward denser media.

Wave Model of Light

The model proposed by Huygens describing light as waves that bend and slow down when entering denser media according to Snell's law.

Rectilinear Propagation (Particle Model)

The principle that light particles travel so fast that they move in straight lines; countered by the question of how two light beams can pass through one another without scattering.

Reflection in the Particle Model

The phenomenon where light particles collide elastically with a barrier like a sphere, resulting in an angle of incidence equal to the angle of reflection ($\angle i = \angle r$).

Reflection in the Wave Model

The phenomenon demonstrated by water waves reflecting off a surface where the angle of incidence equals the angle of reflection ($\angle i = \angle r$).

Refraction (Particle Model)

Newton's proposal that light particles are attracted more strongly toward a denser medium, pulling them toward the normal and causing them to go faster.

Refraction (Wave Model)

Huygens' proposal utilizing Snell's law stating that light bends toward the normal when entering a denser medium because its speed decreases.

Dispersion in the Particle Model

The explanation that red light is refracted the least because its particles have greater mass, while violet light is refracted the most because its particles have a lower mass.

Diffraction (Wave Model)

The wave phenomenon where waves pass through an opening and spread out to fill the space beyond the opening.

Wavelength Bending (Wave Model)

The observation in the wave model that light with longer wavelengths (red) bends less, whereas light with shorter wavelengths (violet) bends more.

Partial Reflection and Refraction (Particle Model)

The hypothesis that particles alternately reflect and refract at a boundary between two media, though Newton's theory ultimately could not adequately explain this phenomenon.

Partial Reflection and Refraction (Wave Model)

The principle that at a boundary between media, a wave naturally undergoes both reflection and refraction simultaneously.

Speed of Light in Denser Media

A critical test between the two models: the particle model predicted light speeds up in denser media due to attraction, whereas observation and the wave model confirm light actually slows down in water compared to air.