The day in which the man contradicted himself
We live in a world based on the principle of non-contradiction according to which everything is identical to itself. On this principle Aristotle based his philosophy, Galileo laid the principles for modern science and some philosophers like Leibniz believed that even God was subordinated to this same principle. However, it would be enough to ask a simple question to a physician that this principle, the basement of humanity, would be proven wrong: “What is light?”
The corpuscular theory
The first scientist to explain the nature of light was Isaac Newton in 1600. His theory saw the light as a set of particles, called photons, that behaved like the common matter. The corpuscular theory explained the majority of the phenomena then known, like the propagation of light in a straight line, the formation of shadows and the refraction.
The wave model
In 1637 the Dutch scientist Christiaan Huygens proposed a model completely different from the previous one, affirming the undulatory nature of light. It compared light to a wave (what is transported, then, is energy and not matter, the same way as a sound wave).
Up to 1801, for the sake of simplicity, the corpuscular model was considered correct, as long as Thomas Young didn’t discover other properties of light like the diffraction and the interference. Being this last one an exclusive characteristic of waves, people started to suppose the truthfulness of the wave model.
Along the years, however, it remained unsolved the problem of the non-ability of light, unlike waves, to circumvent the obstacles, even though some theory explained this problem supposing that light would have a microscopic wavelength.
The turning point: the dualism particle-wave
Who undermined the wave model was Albert Einstein that, with the experiments on the photoelectric effect, demonstrated the groundlessness of Huygens’ theory. This effect consists of a phenomenon that takes place in the conductors that, exposing them to light, emit electrons from the surface. The only possible explanation was considering the light as corpuscular again. This discovery made Einstein won the Nobel Prize in Physics in 1921.
In order to avoid paradoxes, it was then necessary to admit that it was possible to explain some light phenomena with the corpuscular theory and other ones with the wave model. So is the light made of particles or is it a wave? In 1924 the scientist De Broglie affirmed that all the matter would manifest itself with this dualism particle-wave, developing this way the theory of the quantum mechanics. In the end, it was Bohr (colleague and friend of Einstein) to definitively elaborate the principle of complementarity, according to which the wave and particle aspects of a phenomenon can’t be observed at the same time.
This was the day the profession stereotypically more rational, the scientist, declared the failure of the principle of non-contradiction. The discovery of the light dualism has taken the humanity to a even greater level of open-mindedness. And who knows if in the future the researchers won’t discover that we human beings are composed both of particles and of waves and that maybe this wave can exactly be what we have always called “soul”.
“If you have nothing in quantum mechanics, you will always have something”