Photoelectric Effect Video Lecture - Civil Engineering (CE)

everybody knows Albert Einstein for his
theory of relativity and the Nobel Prize
he won for it he also thought I didn't
have in the Nobel Prize for a relativity
I run it for explaining the
photoelectric effect right right of
course sorry
Einstein won the Nobel Prize for his
work on the photoelectric effect which
helped settle the age-old debate of what
light is made of so what is it
okay let's rewind a little Newton had
thought light was made of particles and
his rival Hooke had thought it was a
wave and when technology advanced enough
some experiments proved Hooke was right
that proof and Maxwell's equations
describing Lights behaviour away made
the debate die down until the
photoelectric effect was discovered when
light hits a cable next to another cable
electrons jump from one to the other it
was thought it happened because waves of
light made atoms vibrate until they
ejected an electron but when it was
measured carefully a big contradiction
was found it's only happened for light
of some wavelengths for others no
electrons jumped at all
Einstein was bewildered the
photoelectric effect should work
regardless of the type of light if light
wasn't made of particles and now it
turned out that it couldn't be made of
waves what was it made of after much
reflection he formulated a new
hypothesis combining the two previous
ones
what if light were made not of waves or
particles but of both that is what if
light were made of wave packets that
concept which we now call photons an out
Einstein to write out equations that
explain the photoelectric effect in 1905
this consolidated the idea that light
can sometimes be described as a wave
sometimes as a particle and sometimes as
either
it was a revolutionary view and it
opened the field for quantum physics
Robert a Millikan an American
experimental physicist was unconvinced
by Einstein's conclusions so he set out
to prove him wrong by carefully
measuring the photoelectric effect
however years later Milliken ended up
proving Einstein right and they were
both awarded the Nobel Prize in Physics
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