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INTERVIEW

José Goldemberg: From nuclear physics to ethanol

Researcher speaks of his major contributions to science

Léo Ramos Chaves Goldemberg: creating bridges between academia and political officesLéo Ramos Chaves

At 90 years of age, physicist José Goldemberg, FAPESP’s president, is renowned for his long-standing contributions to the interface between science and public policies, especially on issues related to energy production and consumption. Although he’s occupied various positions, both in the state of São Paulo and in public administration at the federal level, Goldemberg began his career in the 1950s as a researcher in nuclear physics—then a burgeoning field of study. For a quarter of a century he was a scholar in that area, focused on his own scientific production. In the 1970s, he began to distance himself from the field and became interested in what is known today as biofuels research. In this interview, Goldemberg discusses his principal scientific contributions, from the time he was a physicist to his days studying ethanol, which led him to build bridges between the academic environment and the formulation of public policies.

What was the beginning of your career as a researcher like?
For the first 25 years I just worked with nuclear physics. I began around 1950, when the University of São Paulo (USP) was installing a particle accelerator called a betatron. At that time photonuclear reactions were being investigated, it was a new area of nuclear physics. The betatron was a machine similar to the synchrotron in Campinas, but smaller. It accelerated electrons up to 22 million volts and those electrons produced the electromagnetic radiation with which we triggered nuclear reactions. I helped in the assembly of the betatron and worked with it as an experimental physicist. A year or two later, in 1952, I went to Canada, where there was an accelerator identical to that in São Paulo, but it functioned 24 hours without interruption, which greatly facilitated the conducting of experiments. Ours couldn’t function that way due to instabilities in the power grid. I made a complete systematic study of the photonuclear reactions, covering virtually all of the elements on the periodic table. We then compared the data with the theory, which already existed but had not yet been confirmed by experimental data. It was a significant scientific work. In a year and a half, I published half a dozen papers in international journals.

After you returned to Brazil, did you continue in the same area of research?
I came back and stayed here for about five or six years, doing research with the betatron, advising students, and continuing my academic career at USP. In the beginning of the 1960s, Stanford University, which had linear electron accelerators of various sizes, invited me to work with one of them. I was known for my previous work in Canada, and stayed there for two years. A colleague from Stanford, the American physicist Robert Hofstadter [1915–1990], had recently received the Nobel Prize, in 1961, for having measured the spatial distribution of electrical charges in the nuclei of atoms. When I arrived at Stanford, all the physicists were working with the large, 300-million-volt accelerator, which Hofstadter had used to win the Nobel Prize. The smaller accelerator, with 40 million volts, was left just to me. I used the equipment to measure the magnetic moment of the nuclei, which demanded complex equipment.

Which elements did you work with?
I worked with all the elements that I could lay my hands on: lithium aluminum, cadmium, neodymium, etc. Once again, I made a complete systematic study across the periodic table and was able to confirm the theory of electron scattering by the magnetism of the atomic nuclei. That research had a tremendous impact.

Why were you interested in this type of measurement?
At the time, it was pure research, on the cutting edge. Since my measurements confirmed the existing theory, this meant that we were understanding nature correctly. When I returned, Stanford University donated the linear accelerator that I had worked with to USP, and it’s still in operation today at the Institute of Physics. Shortly thereafter, I was invited to be a professor at the University of Paris, which had an accelerator of 300 million volts. There I could measure the spatial distribution of the magnetism of the nucleus of atoms the way Hofstadter had done with the electrical charge of the nuclei. I stayed in France for about a year, but then I had a serious personal problem come up and returned to Brazil.

How did you, in the 1970s, have the idea to calculate the energy spent to produce ethanol and compare that with what it could generate?
At that time the interest in renewable energies and energy efficiency was increasing a lot. During that time I stayed six months at Princeton University, in the United States, in a research group that looked at the issue of energy from the point of view of demand, and not only of its supply. The basic question at that time was whether it was possible to use energy in a more efficient way. In 1975, after the first oil crisis, someone remembered correctly that the first automobiles made by Henry Ford were fueled by ethanol. This was a good fuel compared to gasoline, but had been very expensive at the time. The same idea occurred in Brazil in the 1970s. Here, the ethanol produced from sugarcane cost two to three times more per liter than gasoline. But the sugarcane refinery owners were experiencing a crisis, because the price of sugar was too low on the international market. To save the industry, the federal government began to subsidize the production of ethanol, in order to replace gasoline, which was imported. By that time, I had already been working with energy, and I began to research how ethanol was produced. I did all the calculations with my colleagues and we found that four times more energy was generated with one liter of ethanol than was spent to produce it from sugarcane. The additional energy was simply solar energy captured via photosynthesis, which is renewable. My work gave a scientific justification for the use of ethanol. Even being so expensive, ethanol was a renewable energy and could replace oil. With the construction of more than one hundred refineries, the efficiency of the sector increased, the cost of ethanol production fell, and it ended up becoming competitive with gasoline. Economists know very well that there are productivity gains when the production scale of a sector increases. This is what occurred in the ethanol refineries. We learned to do it in a more productive way.