Unfolding the mysteries of the world, or the universe, in general, has been the prime objective of Physics. Physicists and their contributions proved to be detrimental to this. It was their discoveries that shaped the world of tomorrow. However, there was a time when the relevance of Physics itself was questionable. This was due to the applicability of two different approaches within Physics.
Classical Physics versus Quantum Physics
While Classical physics was solving many problems, its applications were limited. To be specific, Classical physics was only applicable to large particles. Understanding its limitations, a group of scientists worked towards developing a new wave of science. This innovative mindset was disregarded by renowned scientists, including Albert Einstein. The year 1927 was the peak of this debate. A debate that would change the scope of Physics! Before we get to that, it is important to get a gist as to what either side proposes.
Classical Physics
Classical Physics is the physics of macro entities. Some of its key characteristics include Determinism, Continuity, Completeness, and Relativity. This field of physics was architected by Sir Isaac Newton. His laws of motion became a cornerstone in many scientific breakthroughs. Despite its significance, it became a point of debate in the early 20th century.
Shortly after J.J Thomson discovered Electron, physicists reaffirmed the particle nature of matter. It paved the way to many technological inventions including but not limited to, Vacuum Pump, Transistor and Amplifier. However, it wasn’t until De Broglie’s dissertation when scientists began to understand the true nature of the particle. He supported the dual nature of the particle. He believed that “Nature loves symmetry” hence matter should exist in particle nature as well as in waveform.
Quantum Physics
Even before De Broglie’s dissertation, Max Planck believed that energy, hence matters, is composed of discrete packets. He called it a “quanta”. This was the birth of Quantum Physics. This unconventional field is the science for microscopic entities. Its relevance is widespread. Starting from the atomic structure to the big bang, Quantum physics was able to realise its mystery.
As opposed to Classical physics, Quantum Physics was more probabilistic than deterministic. It had different levels of reality. Discontinuous in nature, it went against Newton’s classical theory. This dissimilarity bothered many Physicists. They started disregarding the theory so as to reinforce the classical theory.
Why was Quantum Physics disregarded?
Though Quantum physics promised answers for many uncovered phenomena, it was against Newtonian physics. It was a science of “Maybe” or “Maybe not”. It went against the very fundamentals of Classical physics. While Newton had pointed out the deterministic property of matter, Quantum Physics was encouraging probabilistic property. This was enough to start a huge debate among scientists. To top it all off, was this bizarre concept of not being able to determine the position of a particle. Going into the early 1920s, Scientists had had enough and decided to reboot against it.
Solvay Conference
Solvay Conference, held in Brussels once in every three years or so, has a rich history for making some of the biggest scientific breakthroughs. Founded in 1911, the International Solvay Institutes for Physics and Chemistry invites scientists across the world to solve preeminent open problems. The fifth conference in the year 1927, was no different. Determined to settle the conflict between Classical and Quantum physics, the conference saw renowned scientists such as Marie Curie, Albert Einstein, Paul Dirac, Louis de Broglie, Niels Bohr, Erwin Schrödinger, Wolfgang Pauli, Werner Heisenberg and many others.
Key Players in Solvay Conference
The 1927 Solvay Conference was titled “Electrons and Photons”. Many experts in either of these fields attended the conference. Among the 29 attendees, 17 of them were or became, Nobel Prize winners. The key players of this conference were the ones who questioned the relevance of either theory. They were those who put forward some puzzling thought experiments. In short, they were the ones who made this conference a revolution!
Niels Bohr
Shortly after his graduation, Bohr’s slight modification of the Rutherford model fetched him a Nobel. Bohr revealed that atoms could only equip certain orbits. That was the beginning of his stint at Quantum Physics. Going into the 1927 conference, Bohr took on Einstein and his thought experiments to support the relevance of Quantum physics. As a desperate measure, he used Einstein’s theory of relativity to prove him wrong. His lines: “Einstein, stop telling God what to do” tells how unsettled he was with Einstein’s statements.
Werner Heisenberg
Werner Heisenberg’s uncertainty principle laid the foundation for Quantum Physics. It hinted at the probabilistic nature of the physical world. He went to the conference with a solid proof for his principle. The young scientist merged his theory with Schrödinger’s to develop an analogy between these two branches of Physics. His argument was that, on an attempt to realise the electron’s position, the light disturbs it. This disturbance accounts for the probabilistic position rather than a deterministic one.
Albert Einstein
Albert Einstein religiously believed that the universe must obey laws of physics that are fundamentally deterministic. Einstein had long debates with Bohr. In an attempt to defunct Bohr’s quantum world, he realised a puzzle called Quantum Entanglement. It is still at the heart of the disparity between classical and quantum physics. Bohr had no reply to his question.
After 6 long days, Einstein concluded that “probably all agree that the so-called quantum theory is, indeed, a helpful tool but that it is not a theory in the usual sense of the word, at any rate, not a theory that could be developed in a coherent form at the present time”. He further added, “God does not play dice.”
Erwin Schrödinger
Erwin Schrödinger who developed the equations to prove the wave nature was pro-Classical. Just before the conference, Bohr had invited him to Copenhagen to discuss Quantum physics. He was not satisfied with Bohr’s ideologies, hence decided to attend the Solvay conference to settle the differences, once and for all. Together with Einstein, Schrödinger would question the relevance of the uncertainty principle to defunct Quantum physics.
His 1935 thought experiment, “Schrödinger’s Cat” illustrates what he saw as the problem in the quantum world. Moreover, this thought experiment was conceived from Einstein’s quantum entanglement. This shows his disregard for quantum physics even after the conference.
The “Quantum Revolution”
The 1927 Solvay Conference was the beginning of the Quantum Revolution. Towards the end of the conference, Einstein’s Entanglement remained a puzzle. But it encouraged many scientists to look into the quantum world.
Quantum computing became the face of computing, promising to solve complex algorithms within a fraction of a second. Quantum cryptography promised secure information sharing without the interference of a third party. While quantum sensing uses quantum coherence to measure physical quantity. Upon closer inspection, all of these technologies leveraged the entanglement puzzle in one way or another. So it is safe to assume that the conference had a huge effect on today’s world.
