**Quantum Mechanics**

I consider the methods of quantum mechanics fundamentally unsatisfactory. ~ Albert Einstein

Nobody understands quantum mechanics. ~ Richard Feynman

Quantum theory cannot be extrapolated to complex systems. ~ Swiss theoretical physicists Daniela Frauchiger & Renato Renner

There is no quantum world. There is only an abstract description. ~ Niels Bohr

The subatomic particle Matryoshka became a babushka when French physicist Louis de Broglie speculated in 1924 that all particles in motion might exhibit wavelike behavior. A fascinated Austrian physicist Erwin Schrödinger took the idea and ran with it, unknowingly injecting uncertainty into quantum mechanics with his 1926 publication that described an electron as a wave function rather than a particle at a particular point in time. This became known as Schrödinger’s equation.

Schrödinger formed his fundamental equation during an erotic tryst with a lover, on holiday in Arosa Switzerland. In an equal and opposite reaction, Schrödinger’s wife proved that what goes around comes around, by having an amorous relationship with German mathematician and theoretical physicist Hermann Weyl. Or, as Weyl might have said, “it all adds up.”

Schrödinger’s equation had mathematical elegance and accounted for many spectral phenomena that Bohr’s particulate atomic model failed to explain. But Schrödinger’s wave function was difficult to visualize and so faced opposition.

The wave did not waver. Instead, the idea of wavy particles matured into quantum field theory, also known as quantum theory and quantum mechanics.

I do not like it, and I am sorry I ever had anything to do with it. ~ Erwin Schrödinger

In 1925, German physicist and mathematician Max Born formulated a matrix representation of quantum mechanics, based upon interpreting Schrödinger’s equation as a probability function for an electron’s location. Born’s theory formally introduced wave/particle duality: an electron had properties of both a particle and a wave, thus reconciling opposite views.

Einstein had essentially come to the same conclusion in 1905, when he argued that radiant energy consisted of quanta. But Einstein did not appreciate the implications of his discovery. It would not be the last time that Einstein failed to fathom the import his own conclusions.

At the heart of quantum field theory (QFT) is wave/particle duality. QFT stuffs the basic bits of Nature into quanta while acknowledging their wavy properties as paramount.

QFT proposes an umbrella for understanding the fundamental nature of existence with a quantum that defies precise characterization as to position, path, and speed. That makes a quantum amenable to being mathematically sketched simultaneously as both a particle and a wave function.

Subatomic particles are far from solid. They are nothing like matter as we know it. Much of the time they seem more like waves than particles. Whatever matter is, it has little, if any substance. ~ English physicist Peter Russell

A quantum is not a particle, like some itty-bitty billiard ball, but instead a little localized chunk of ripple in a field that deceptively looks like a particle. Understanding a particle is more about wave interactions than about particulate properties. It is a story of field behavior, not characterizing fantastically fleeting fragments.

Particles are epiphenomena arising from fields. Unbounded fields, not bounded particles, are fundamental. ~ American theoretical physicist Art Hobson

A photon, or particle of light, is more essentially a vibratory wave matching the intensity of the fields that surround an electrically-charged object: electromagnetic radiation. This radiation comprises electric and magnetic field components oscillating in phase perpendicular to each other and perpendicular to the direction of energy propagation.

The oscillation is a wave which yields a quantum. Photons, and everything else, are interconnected energetic vibrations that appear particulate.

Quantum mechanics at its heart is a statistical theory. It predicts probabilities of outcomes. This probabilistic nature of quantum theory is at odds with the determinism inherent in Newtonian physics and relativity, where outcomes can be exactly predicted given sufficient knowledge of a system. Perhaps quantum systems are controlled by hidden variables that determine the outcomes of measurements. ~ American physicist Lynden Shalm et al