Nature of Light

Question 1

Tactile theory

Answer 1

Light consists of filaments (tentacles) emitted by the eye. When they came into contact with an object, it was possible to see the object.

Question 2

Emission theory

Answer 2

Pythagoreans believed that light traveled as a stream of fast-moving particles. Objects sent out beams of light that would ricochet off objects and enter the eye.

Question 3

Particle/corpuscular theory

Answer 3

Newton’s theory that stated light consisted of particles that traveled in straight lines.

Question 4

Wave theory

Answer 4

Christiaan Huygen’s theory that stated light consisted of waves and exhibits wave-like properties

Question 5

Electromagnetic theory

Answer 5

James Clerk Maxwell’s theory that stated light was an electromagnetic wave with the same properties as the other electromagnetic waves.

Question 6

Quantum hypothesis

Answer 6

Max Planck’s theory that suggested light was transmitted and absorbed in small bundles of energy called quanta.

Question 7

Rectilinear propagation

Answer 7

light travels in straight lines. (Newton)

Question 8

Visible spectrum

Answer 8

Red = high frequency, low diffraction
Violet = low frequency, high diffraction

Question 9

Galileo Galilei

Answer 9

measured speed of light from the distance between two hilltops (speed was extremely fast)

Question 10

Olaus Roemer

Answer 10

measured speed of light using Jupiter and its moon, Io. (2x10^8m/s)

Question 11

Christiaan Huygens

Answer 11

measured speed of light using the size of Earth’s orbit (16 2/3 Earth diameters/s)

Question 12

Jean Foucault

Answer 12

measured speed of light using rotating mirror and stationary mirror (2.99796 m/s)

Question 12

Armand Fizeau

Answer 12

measured speed of light using rapidly rotating toothed wheel and a mirror (3.13300x10^8m/s)

Question 13

Albert A. Michelson

Answer 13

measured speed of light using a rotating, eight-sided mirror. (2.99729x10^8m/s)

Question 14

Thomas Young

Answer 14

discovered that light has wave-like properties through the interference of light. (created the equation x=lambdaL/d)

Question 15

Photoelectric effect

Answer 15

the ejection of electrons from the surface of a metal by light. Behaviour is that of a particle and is determined by frequency.

Question 16

Wave Particle Duality

Answer 16

When light passes through space or through a medium, it’s a wave. When light interacts with matter, it’s a particle.