towards an analysis of errors made by university students ... - DSpace

property as well as a wave property, and this is one of the
paradoxes of physics. Newton's conception of light was a stream
of particles, which he endowed with something
in the nature of
pulsating properties in an attempt to account for certain
phenomena which we can now easily explain on the wave
theory.
He felt the need for the double aspect, the particle and
the
periodic, and provided for it in his
theory.
T9P - Text number 9 - Physics
PARTICLES OR
WAVES?
(From THE MYSTERIOUS UNIVERSE by James
Jeans)
(Part one)
The most obvious fact about a ray of light, at any
rate to superficial observation, is its tendency to travel in
a straight line; everyone is familiar with the straight edges
of a sunbeam in a dusty room. As a rapidly-moving particle of
matter also tends to travel in a straight line, the early
scientists, rather naturally, thought of light as a stream
of
particles thrown out from a 'luminous source, like
shot from a
gun. Newton adopted this view, and added precision to it in his
'corpuscular theory of light'.
Yet it is a matter of common observation that a
ray of light does not always travel in a straight line. It can
be abruptly turned by reflection,
such as occurs when it falls
on the surface of a mirror. Or its path may be bent by
refraction
suchas occurs when it enters water or any liquid medium; it is
refraction that makes our oar look broken at the point where
it