Huygens considered light to be a luminous disturbance
of springy corpuscles of ether
propagated by spherical waves from each point in its path
that add up to determine light’s direction.
Huygen’s principle explained
reflection and refraction,
but not defraction.
Fresnel explained defraction
by adding to Huygen’s principle
that observation that light waves
interfere with each other.
Arago spot
The spot that shouldn’t exist
in the center of a circular shadow
helped show that light
behaves like waves.
Geometry of corpuscles
Huygens applied
compass and ruler,
geometric methods,
to mythical corpuscles of ether.
It should perhaps be claimed
that what he made
was not a description of light
but a paper and pencil model of it.
Fresnel, working a hundred and thirty years after Huygens,
expressed the circular disturbances made by each corpuscle of ether mathematically.
The theory may seem archaic; however, it still predicts
the behavior of electromagnetic disturbances in quantum field theory.
Fresnel, working a hundred and thirty years after Huygens, expressed the circular disturbances made by each corpuscle of ether mathematically. The theory may seem archaic; however, it still predicts the behavior of electromagnetic disturbances in quantum field theory.
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