He Once upon a time From quantum it usually starts in 1900 with Max Planck, or with Werner Heisenberg in 1925. But the physicist and academic of the SAR José Manuel Sánchez Ron warns that establishing a beginning is never easy. His new work, History of quantum physicswhich publishes planet and will consist of three volumes, adds the international year of quantum science and technology, declared by the UN. Sánchez Ron chooses as an starting point of the 18th century, with Isaac Newton. “Newton’s shadow is elongated,” says the academic in this interview.
Why Newton?
José Manuel Sánchez Ron: The connection between Newton and quantum physics is in The opticshis great book of 1704. Instead of starting by Planck and the discovery of the Luz How many in 1900, I decided to do it along the path that leads to Planck. It was Newton who discovered that the light breaks down in colors when passing through a glass prism, generating a spectrum. Newton did not believe in the wave-particle duality that was claimed later, but his experiments with prisms were revolutionaries. It was also Newton who invented the concept of black body (strictly a fiction, an unattainable object).
Could the black body also be a good beginning for the history of quantum physics?
It is at the beginning of the 1860s when the Berlin chemist Robert Bunsen and Prussian physicist Gustav Kirchhoff study spectroscopy and introduce the concept of black body, without which quantum physics would not have developed. After them, Max Plank arrived, who wanted to find a formula for the radiation of the black body. Plank used classical physics and, in a somewhat bungling way, found a law that worked, but could only explain by introducing discontinuity into radiation, that is, understanding that it is not emitted or absorbed continuously, but in “packages”. How many were born from the study of the radiation of a black body, which remains key in the 21st century.
Quantum physics flourished in the 1920s and 1930s. All the participants of the quantum gold age were European?
Until the 1930s, quantum physics was European. In Gontinga, in the state of Baja Saxony, Germany, Max Born worked. Many young American physicists, for example Oppenheimer, did their thesis in Gontinga. In the Cavendish Laboratory of the University of Cambridge, JJ Thompson identified the electron. Manchester arrived the Danish Niels Bohr who, newly doctorate, managed to fit Planck how many of Rutherford’s atomic model. Europe was the honeycomb to which all bees went.
Is it a moment with a great intergenerational connection?
Certainly. Together with the already established Einstein, Planck, Sommerfeld, Born, Schrödinger, there are young Heisenberg, Pauli, Dirac, Oppenheimer and Bethe.
Why especially Germany?
England was also very powerful. Newton’s shadow was very elongated. But Germany obtained hegemony. It is something I developed in one of my books, THE POWER OF SCIENCE. The European impulse began before quantum, with Justus von Liebig and organic chemistry, which allowed dyes, the pharmaceutical industry, the agricultural, etc. The authorities realized that science generates industry and, with it, attracts students from all over the world. From there companies like Basf were born. Another example is Siemens with the development of electromagnetism. The beginning of the application of science to the industry is, above all, German.
In addition to generating money, was quantum physics the great intellectual discussion of the twentieth century?
Yes, and for this the central place was Copenhagen, which became Mecca of quantum physics. In 1925 Heisenberg produced the first more or less coherent formulation of quantum phenomena, quantum mechanics. Then Schrödinger, an Austrian, formulated another equivalent version, the undulating mechanics. And Paul Dirac. Max Born, with his optical studies, introduced probability.
From all this the famous interpretation of Copenhagen was built, which is a huge intellectual challenge. It was formulated at the famous 1927 Solvay Congress.
The Fifth Solvay Conference of Physics of 1927 is known as the most intelligent photography ever taken, for its representation of the world’s main physicists gathered in a single shot. With the presence of a woman, Maria Salomea Skłodowska-Curie- Wikimedia Commons, CC By
What is the basis of Copenhagen’s interpretation?
The basis of Copenhagen’s interpretation says that a system is in all its possible states until it is observed. It is what is known as the collapse of the wave function. The system is specified with some probability in one of its states.
This is difficult to swallow, that’s why it was called – and is still known as – interpretation. It generated a scientific and intellectual discussion that has not yet ended.
As important as Darwin’s theory of evolution was in his day?
The theory of evolution is a great historical moment for life as we know it on earth. It is the biggest in science, it allows you to see everything in a different way. But you can understand the evolution theory, there is nothing in it that violates our way of knowing.
However, quantum mechanics do, violate what we understand by reality. He says that when I observe, what I observe is specified in a possibility with a certain probability. Here the famous Schrödinger cat metaphor is expressed, which is or not if we look or not. How is this possible? This violates everything we can understand.
From quantum physics it is often said that we will never be able to understand the world of all.
You can never know what will happen tomorrow, but today quantum physics faces us with our cognitive limitations. At the same time, and it is a paradox, we are able to find theories that go against our way of understanding and yet work. One thing is consistent with another. Quantum physics allows us to understand, for example, the periodic table of the elements that were obtained in an empirical way.
But the quantum describes another property that leaves you patidifuso: quantum entanglement. The important thing is not Dead-grate catbut a property that says that two particles, if they move away, are still intertwined. What happens to one, affects the other. This violates special relativity. Entreasidation is already being used in quantum computing to transmit safe information.
Did the unseatting of physicists in World War II ended the hegemony of Europe?
It is not fair to talk only about physics. They were physical, but also mathematicians, biologists, artists, psychiatrists, etc. Those who abandoned Europe. In the United States there was already an advanced scientific development, but it is true that the landing of great European scientists enriched it.
And then, the United States took off. Did the discovery of transistors mean a before and after?
In the United States something crucial happened. In Europe, universities had created institutes and industries appeared based on research, but in the US it is the industry itself that bets to do toe research.
In Bell Laboratories Arno Penzias and Robert Wilson worked, in charge of studying communication antennas, and discovered the cosmic microwave cosmic radiation (CMB), that of the Big Bang. Decades before, also in Bell, John Bardeen, Walter Houser Brattain and William Shockley laboratories invented the transistor in 1947.
With the transistor came the chips, an application of quantum physics that has transformed the world. The chips have changed how we drive, have led to microwave ovens, teleworking … Shockley, one of the three inventors of the transistor, decided that he wanted to make money. He founded a company in a place near Stanford. It was the germ of Silicon Valley.
Does Europe have something to say today in quantum physics?
Europeans realized after the war that could not compete in experimental physics of high energies. In the United States, large particle accelerators had already been created. Then, in the 1950s, several European countries joined to found the CERN. Now, the LHC (Large Hadron Collider) is the most powerful particle accelerator in the world. It has been in Europe where the Higgs boson has been discovered.
With the crisis that Donald Trump is generating in the US, does Europe have any possibility of recovering hegemony?
Science is the most important source of the wealth of the United States. That is why it is now said so much that Donald Trump is shooting at his feet when he imposes cuts and restrictions on large universities. But look, at the Free University of Berlin there is a photograph of all the Nobel Awards that they taught there. There are more than 20, few compared to Harvard 161.
The European splendor time passed, but it doesn’t have to return. Of course, it could only happen based on the European Union. After all, the United States is a union of states. We have a possibility, but we must know how to use it, and it is complicated because nationalisms in Europe are powerful.
No one said it was easy, right?
Nor do it not be possible.
This article was originally published in The Conversation.