On
the wave-particle duality of light.
or
It’s
a matter of time, space, and relativity.
Understanding light is the key to understanding the universe. Not just because emitted or reflected electromagnetic radiation –light – allows us to see the cosmos, but because the rules found to govern the genesis and behavior of light may lead to deciphering the actual nature of all subatomic particles and the structure of the universe.
The
Paradigm
Figure
1 Absorption and emission of photons.
Photons of light are produced when an atom’s electrons drop from higher to lower energy states. Introductory physics teaches that the photons of light behave both as waves and particles. Its wave like nature can be demonstrated by the interference pattern produced during a double slit experiment. Its particle nature, the photon, can best be shown by photoelectric effect. Its dual nature, by the way light reflects and refracts. Quantum physics theorizes the wave-particle duality for all matter, but is most noticeable in small, subatomic, particles.
A paradox arose when investigating lights duality. In
a double slit experiment set up with one photon being produced at a time, an
interference pattern was still seen; it was as if the photon was interfering
with itself. But if a particle detector was placed in one of the slits the
interference pattern disappeared – the photons ceased to act as waves and
behaved as particles.
Beyond
the Paradigm
How light can behave both as a wave and a particle is
easier to explain if you approach the problem from the photon of light’s
perspective. An important principle of relativity states that as speeds increase,
time slows. At the speed of light, time ceases to have meaning; it stops. Therefore
light itself does not experience time. Everything that happens to a photon in
our universe, from the time it is generated till it is absorbed - as far as the
photon is concerned - happens simultaneously. Distances are meaningless to
light. If distance equals rate times time and time goes to zero, all distances
go to 0. For light there is no difference between traveling to an abutting atom
or clear across the universe. The distance is the same; there is none. When a
photon is produced, it fills the space it exists in. From the light’s
perspective, it instantaneously fills its universe. But in the universe as we
perceive it, the photon would be described as a wave of energy moving away from
its source at the speed of light (C). And if unabsorbed, the light would
continue to spread out to fill the universe. But if at any point in our
perceived universe the photon is absorbed, the apparent wave disappears. Thus
light is a particle and appears as a wave. In the double slit experiment, the
photon does interfere with itself because the photon is entering both slits at
the same time. If the photon is absorbed, it disappears everywhere at the same
instant.
Questions
that need answers:
How does an electron dropping
energy levels actually produce a photon?
How does an electron absorb a photon?
When electrons drop energy levels they release
energy in the form of photons. The more
levels dropped the more energetic the photon and the greater the time
difference between levels. What happens to time as electrons are transitioning
between energy levels?
Are the discreet energy levels of atoms related to
the time differential between levels?
What effect does speed of a charged particle have on
the particle’s charge?
If the faster a charged object is moving the slower
its time flows (even if the difference is minuscule), what effect does the
difference in time flow have on the particle’s charge?
If energy equals mass times the speed of light
squared, and at the speed of light time stops; how important is time to the
structure of what we call mass or matter?
What is the role of time, if there is one, in the
wave-particle duality of all matter?
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