Albert Einstein: The Emergence Of Quantum Mechanics

Every moment, our lives, our world and even our universe are governed by laws of physics-the explanations to all natural phenomena. One of the most brilliant physicists in the history of mankind, Albert Einstein, made great contributions to the development of theory of relativity and quantum physics. Despite of his profound excellence, Einstein was proven wrong of so-called “quantum entanglement”. He strongly denied its possibility as he once described it as “spooky action at a distance .” Even in nowadays, it is indeed difficult to believe that measurement of one particle would affect the other paired particle no matter how far they are apart from one another. However, regardless of how strange the nature is to us, that is how the universe

The laws of classical mechanics which are used to describe motion and energy of an object cannot fully explain the behavior of a quantum particle. This need led to the emergence of quantum mechanics. Classical mechanics and quantum mechanics are like dogs and cats; they are very different. The fundamental difference between the two is the property of uncertainty in quantum mechanics. Recall the fact that classical mechanics allows precise prediction of position and momentum of an object as a function of time. However, in quantum mechanics, Heisenberg uncertainty principle states that there is a limit in precision of measuring two paired measurements simultaneously. For instance, more precise measurement of position influence and thereby limits the degree of precision of momentum measurement. The uncertainty principle applies to the macroscopic world as well, but its effect is neglected due to the extremely small value of Planck’s constant (h). Plank’s constant is the represents the “quantum of action ” in which quantum is the smallest unit of energy (thus energy is discrete) and electron can only reside to lower discrete energy level and cannot fall in between two energy levels. The uncertainty principle applies to particles with wave-like characteristics which Louis de-Broglie showed that all objects in motion have de-broglie wavelength related to its mass and

The particle-wave duality of atomic and subatomic particles is one of the most fundamental properties in the quantum world. Essentially, this indicates that small particles such as electrons exhibit both particle and wave-like characteristics. An electron has physical properties like mass, volume, and momentum, but it travels in oscillation like a wave and exists in multiple states- not localized in one location. Young’s double-slit experiment was the key to identify particle-wave duality of electrons. Normally, when particles are passed through the double-slit, only two bands are present in the screen (one from each slit). Unexpectedly, when a beam of electrons were passed, multiple bands of maxima and minima, the interference pattern was observed. The interference pattern represents superposition which is a wave characteristic. The double-slit experiment successfully showed the wave characteristic of