Lecture 2

Question 1

How did classical physics define matter

Answer 1

• Particular(Chunk-Like)
• Can be held
• Weighted
• Can change quantity one by one
• Cannot refract or diffract
• Moves in definite paths

Question 2

How did classical physics define energy

Answer 2

• continuous( Wave-like)
• Massless
• Quantity can change continuously
• Can refract and bend when it propagates through different media
• Can experience properties of constructive and destructive interference
• Move in all directions

Question 3

What two fields does Light propagate through

Answer 3

Electric and magnetic

Question 4

What three experiments changed our understanding of light

Answer 4

Blackbody radiation, Photoelectric effect, Atomic spectra

Question 5

What is blackbody radiation?

Answer 5

The light emitted off an object after it is heated to various temperatures.

Question 6

Can the classical definition of light as wave explain black body radiation

Answer 6

CP definition would have meant that at extremely short wavelengths the intensity of the light emitted to be infinite, which is impossible.
CP said that more amplitude = more energy however this concept contradicts the idea of the peak in the graph.

Question 7

blackbody radiation: How do atoms change their energy

Answer 7

Atoms change their energy discontinuously(steps or chunks) by emitting or absorbing light in discrete packets called quanta

Question 8

What did the blackbody radiation experiment prove.

Answer 8

Energy must be quantized

Question 9

photoelectric effect: which misconception did this theory deface

Answer 9

That energy travels in waves

Question 10

Photoelectric effect: what are the two things wave theory could not account for

Answer 10

Presence of threshold frequency
absence of time lab