9.4 Light as a Wave or a Particle?
Time Frame for Newton/Huygen
• Newton (1643-1727)
• Born in England
• Huygen (1629 –1695)
• Born in Holland
What is the basis of each
model/theory:
Newton: _____________________
Huygens:______________________
Comparison
Rectilinear
Propagation
Rectilinear
Propagation
Diffraction
Diffraction
Reflection
Reflection
Refraction
Refraction
Partial ReflectionPartial
Partial Refraction
ReflectionDispersion
Partial
Refraction
Dispersion
Explanation/Description
Explained
Well by the
Explanation/
Explained Well
Explained
well
Theory?by Huygens’
Description
by the Newton’s
Theory?
Theory?
Comparison…
Rectilinear
Propagation
Reflection
Diffraction
Reflection
Refraction
Partial ReflectionPartial Refraction
Explanation/Description
Explained
Well by the
Explanation/
Explained Well
Explained
well
Theory?by Huygens’
Description
by the Newton’s
Theory?
Theory?
- Light is
absorbed fully on
black surfaces
yet particles
reflect off any
surface
In summary,
Huygens’wave theory explained many of the properties of
light, including reflection, refraction, partial reflection–
partial refraction, diffraction, dispersion, and rectilinear
propagation.
The wave theory was more valid at that time than
Newton’s corpuscular theory, but because of Newton’s
reputation in other areas of physics, the corpuscular
theory would dominate for 100 years,
…until Thomas Young provided new and definitive
evidence in 1807.
Read Section 9.5
1. What evidence did Thomas Young give
to support the theory that light is a
wave?