physical science, light and mechanisms

1. PHYSCIE-LESSON 4

2. EMERGENCE OF
LIGHT
01

3. The Emergence of Light: Newton and
Descartes
Many scientists studied
the behavior of light.
They conducted
experiments using a
prism to explain the
emergence of the colors
of light upon passing it.
Rene Descartes
Isaac Newton

4. Light was a mechanical
property of a luminous object
and a transmitting medium.
(refraction)
Rene Descartes
Transmitting medium could be air/water
Luminous objects – produce or generate
light

5. PARTICLE THEORY OF LIGHT
Light is composed of particles of
matter called CORPUSCLES
which are emitted in all direction
from a source.
Isaac Newton
travel at a straight
line

6. WAVE THEORY OF LIGHT
He proposed the wave theory of
light in 1678 in which the light is
made up of waves.
Christian
Huygens

7. WAVE THEORY OF LIGHT
▪ Light is a form of energy
and has a wave
characteristics.
▪ Light wave has short
wavelengths.
▪ Light coming from a
source sends out waves in
a medium called ether.

8. DUAL PROPERTY
OF LIGHT

9. DUAL PROPERTY OF
LIGHT
As particles
light travel in
straight lines,
producing a
shadow when
they hit an
obstruction.

10. DUAL PROPERTY OF
LIGHT
As a wave,
light can
diffract or
bend around
an object.

11. How Light Behave as a Wave
Light reflects
REFLECTIO
N
REFRACTIO
N
DIFFRACTI
ON
Wave Properties
Light refracts Light diffracts

12. How Light Behave as a Particle
Particle Properties
Photons of light act like
particles
M1 M2
▪ stationary
▪ Kinetic energy
▪ momentum
Particle transfer

13. PROPERTIES OF
LIGHT
02

14. Effect of Materials on Light
Materials can be classified based on how it
responds to light incident on them:

15. transparent
translucent
opaque

16. REFLECTION
Light can bounce off materials in 2 ways:
The angle of incidence is
equal to the angle of
reflection.

17. Difference:
Regular/Specular
reflection Diffuse reflection

18. REFRACTIO
N
Measure of how much light
refracts in a medium
Bending of light as it passes through
materials of different optical density.
Index of Refraction

19. INTERFEREN
CE
When 2 light waves meet, it can create either
constructive or destructive interference based on
how the crest and troughs of the waves meet.

20. Young’s Double Slit
Experiment
Conducted by Thomas Young in early
1800’s.
constructiv
e
destructive

21. Light spreads out after passing through/by an
opening or edge.
DIFFRACTIO
N
Clouds silver
lining Slightly
open door

22. Thanks for listening!