This document summarizes the wave and particle properties of light. It describes the anatomy of a wave, including the crest, trough, and rest position. It defines key wave properties like wavelength, amplitude, frequency, period, and velocity. It also discusses wave interference and behavior. The document then summarizes the early "corpuscular theory" that viewed light as particles or corpuscles. It presents an experiment from 1873 by William Crookes using paddles and a glass capsule that was supposed to demonstrate the particle nature of light but instead showed wave-like interference patterns.

1. 
The duality of the light
Tesa Reimat, Anna Solà and Gisela Solé

2. The duality of the light
The light
Wave
Definition
and anatomy
Properties
Waves’
behavior
Particle

3. Definition and anatomy
Anatomy
•Rest position: the centre of the wave.
•Crest: the point on the wave with the maximum positive displacement
from the rest point.
•Trough: the point on the wave with the maximum negative displacement
from the rest point.
Definition:
A wave is a disturbance that travels through a medium from one location to another location.

4. Properties
λ Wavelength: the distance from crest to crest. It is represented by λ (lambda).
A Amplitude: the distance from the rest position to the crest or the trough.
v Frequency: the number of waves per second.
T Period: the amount of time it takes to complete one cycle. It is represented by the letter T.
c Velocity: the speed the wave travels. It is calculated by the equation v = λ / T.

5. Waves’ behavior
The interference is a phenomenon in which two waves superimpose to form a
resultant wave of greater or lower amplitude.
When this process occurs, the waves produce an interference pattern like the one in
the picture.

6. Corpuscular theory
Light is made by a flux of bright
particles which name is Corpuscles.
This particles explain their rectilinear
propagation, their reflection on
opaque surfaces and their refraction
when the environment changes.

7. Experiment
Invented by William Crookes (1873)
4 paddles
1 shaft
Glass capsule

8. Experiment
What was supposed to happen? What happens?

9. Experiments

10. Thanks for
your attention!