What Is Quantum Physics and Who Invented It?

A quintessential arena of science, quantum physics is a term that’s recognised by most, but understood by few. Also known as quantum mechanics or quantum theory, the name describes a fundamental branch of physics that explains the nature and behaviour of matter and energy, at an atomic and subatomic level. Yet despite the fact that its widely recognised as the theoretical basis of modern physics, it’s not a new concept.

The early days

Its origins can be traced back to 1900, when physicist Max Planck put forward his controversial quantum theory to the German Physical Society. Determined to pinpoint the reason why the colour of radiation emitted from a body changes from red, orange and blue, Planck made an assumption that like matter, energy exists in individual units, as opposed to a constant electromagnetic wave. As a result, this makes it quantifiable, which allowed him to answer his initial question. It was Planck’s recognition of individual units that materialised as the first assumptions of quantum theory.

He then went on to create a complex mathematical equation to explain the phenomenon, which he dubbed quanta. It ruled that at certain discrete temperature levels, body energy radiation occupies different areas of the colour spectrum. He won the Nobel Prize in Physics for his innovative theory in 1918, which paved the way for thirty years of refined contributions from fellow scientists.

The building blocks of quantum physics

Albert Einstein was another major quantum physics influencer, theorising in 1905 that it wasn’t just energy, but radiation itself that was quantised. In 1924, French physicist Louis de Broglie put forward the idea that the makeup and behaviour of energy and matter aren’t separated by any fundamental differences, with both able to behave as though they are made of particles or waves when observed on atomic and subatomic levels. Cue the emergence of the ‘principle of wave-particle duality ’ theory. German theoretical physicist Werner Heisenberg was another pioneer to make ground-breaking contributions, proposing that it’s impossible to make precise, simultaneous measurements of two complementary values. This gained fame as the uncertainty principle, and was the inspiration for Albert Einstein's notorious comment, "God does not play dice."

Complementary expressions

Branching out from quantum theory itself are two major expressions, known as the Copenhagen interpretation and the many-worlds theory. The first was put forward by Niels Bohr, while the latter is favoured by the likes of Stephen Hawking and the late Richard Feynman.

As well as quantum physics, the theory of quantum chemistry is also a keynote part of contemporary science. ‘Molecular Rotational Resonance Spectroscopy - Chiral Analysis without Chromatography’ asserts that in order to make progress, the rotational spectroscopy community needs to validate the use of quantum chemistry as a method of accurately calculating molecular parameters.