Question

Which ideas held by the ancient Greeks have been at least partially supported by scientific experiments, calculations, and observations made throughout history? Check all that apply.

Light is a wave or disturbance that travels through spaces in the air.
Light is a substance carrying particles that flow from a light source.
Light is a stream of rays that comes with great velocity from the eyes of an observer.
Light is the result of rays that leave the eyes, reflect off an object, and interact with sunlight to become visible.
Light is made of a combination of electric and magnetic fields that travel at the speed of light.

Answer 1

Select: 1, 2, and 5.

Brief reasons and caveats:
- 1 (wave/disturbance): Supported — interference, diffraction, and related experiments (Young, Fresnel, etc.) show light has wave behavior. Caveat: light doesn’t need "air" to travel (it travels through vacuum and other media), and the full description is electromagnetic (see 5).
- 2 (particles from a source): Partially supported — Newton’s corpuscular idea was an early particle model; in modern physics light is quantized into photons (photoelectric effect, Compton scattering), so light has particle-like behavior. Caveat: it’s not a classical “substance” flowing like macroscopic matter; quantum theory gives the correct particle picture.
- 5 (electric + magnetic fields at c): Strongly supported — Maxwell’s equations predict electromagnetic waves that travel at the speed of light; this is the correct classical description of light.

Not supported:
- 3 (rays emitted from the eyes): Refuted by experiments and by the correct understanding that light enters the eye from external sources.
- 4 (rays leave the eyes, reflect, then interact with sunlight to become visible): Not supported; vision results from light from sources (or reflected off objects) entering the eye, not rays leaving the eye that must then “interact with sunlight.”