Albert Einstein was a German-born theoretical physicist who is most famous for his theory of relativity, despite it not being what he received his Nobel Prize for. Quantum mechanics is the fundamental model in physics that describes the nature of the smallest scales of energy levels of atoms and subatomic particles. It differs from classical physics in that energy, momentum and other quantities are restricted to discrete values and objects have characteristics of both particles and waves.
The model quickly developed in the 1900s from scientist Max Planck’s original solution around black-body radiation.
Dr Einstein added to this idea when he proposed the photoelectric effect – the emission of electrons or other free carriers when light falls on a material.
In turn, the physicist received the Nobel Prize for this observation, but it was not the end of his involvement in quantum mechanics.
In 1925, Niels Bohr and Werner Heisenberg soon came up with the Copenhagen Interpretation of the quantum mechanics model.
Their idea, which is still widely used today, theorised that physical systems generally do not have definite properties prior to being measured and quantum mechanics can only give the probability to a certain level.
Einstein strongly rejected this idea, as he believed there must be an answer for everything, famously saying: “God does not play with the dice.”
Amazon Prime’s “Secrets of Quantum Physics” revealed how a war waged on between Dr Bohr and Dr Einstein in the 1900s.
Professor Jim Al-Khalili, from the University of Surrey, detailed in 2015: “The battle raged for decades, it was fought across the world in universities, bars and cafes – reducing grown men to tears.
“Einstein was convinced he had found a fatal flaw in the Copenhagen Interpretation.
“At the heart of his argument was an aspect called entanglement – the incredibly close relationship between a pair of quantum particles who’s fate are intertwined.
“Imagine the two particles as two spinning coins – the Copenhagen Interpretation says that, until you measure them, neither are heads or tails.
“When we stop the first coin, because the first coin was heads, the second coin should be tails – but you can’t predict what they will be – only that they will be opposite.”
However, while Einstein refused to believe the idea, his theory of relativity could not strongly back up his claims and so the majority of the scientific community was happy to accept Dr Bohr’s idea.
Mr Al-Khalili added: “In the mid-1930s, as the world plunged into war, there was no way to answer this question.
“The battle to understand the nature of reality was deadlocked.
“War rolled across Europe and many scientists fled to the United States.
“Then as World War 2 led to the Cold War, American science, backed by dollar bills, and a new vision boomed.
“The idea led to the creation of semiconductors, produced lasers, made breathtaking medical advances and breakthroughs in nuclear power.
“Quantum mechanics was so successful that most physicists chose to deliberately ignore Einstein’s objections.”