Newtons Corpuscular Theory of Light

Question 1

what was Newton’s Theory?

Answer 1

• proposed light was made from tiny particles called corpuscles that travel in straight lines

Question 2

how did Newton explain reflection?

Answer 2

• corpuscles travelled in straight lines towards reflective surface
• they experience a repulsive force that pushes them away
• force causes corpuscles to bounce off at same angle they arrived

Question 3

how did Newton explain refraction?

Answer 3

• corpuscles experienced an attractive force from the denser medium
• force pulls corpuscles towards the normal, making angle steeper
• attraction causes corpuscles to speed up in denser medium

Question 4

what did Huygen propose

Answer 4

• light was a wave
• universe was filled with a massless medium

Question 5

explain how Huygen thought light travelled?

Answer 5

• every point on a wavefront acts as a secondary wave source
• these secondary wavelets spread out in all directions at same speed as original wave
• new wavefront is formed by the tangent of these secondary wavelets
• explains how waves propagate forward

Question 6

why did youngs double slit oppose newtons theory but support huygen?

Answer 6

• if light were made of particles, they would pass through and create two bright spots, no interference pattern
• interference pattern supported the idea that waves spread out and overlap

Question 7

what was maxwells wave equation?

Answer 7

c = 1/ sqr(uoeo)

Uo - permeability of free space

Eo - permittivity of free space

Question 8

how do transverse waves work?

Answer 8

• electric field and magnetic field oscillate perpendicular to each other and to direction of wave propagation
• a changing electric field induces a magnetic field and vice versa

Question 10

what does f represent in c = 4fdn

Answer 10

f is the lowest frequency at which no reflected light can be seen

Question 11

how are eo and mo related?

Answer 11

eo is related to electric field stregth due to a charged object in free space

mo is related to magnetic flux drnsity due to current carrying wire in free space

Question 12

what is a perfect black body

Answer 12

• an object that absorbs all of the radiation on it and does not reflect or transmit any radiation

Question 13

what was plancks interpretation?

Answer 13

em radiation emitted in quanta

energy of quantum is relates to a single frequency

only exist in intergers