In this era of big science, basic physics is usually tested in huge laboratories such as CERN and LIGO, and mavericks who have a major impact through their intuition are becoming rarer. Therefore, those who did this in the past have almost mythical qualities. Due to the complexity of many research fields, their excellent guesses have changed history in a way that is harder today, often requiring large-scale collaboration.
Twenty years have passed since the death of the controversial British astrophysicist Fred Hoyle on August 20, 2001. Fred Hoyle was an anti A traditional man, he is known for his stubborn adherence to marginal beliefs and his major contributions to science. Both the good and the bad in his career stem from the same source-he likes to make comprehensive predictions based on intuitive calculations, as well as the intuitive sense of correct interpretation based on the laws of nature.
Hoyle’s main debate partner—at least from the media’s point of view—is the Russian-Ukrainian-American physicist George Gamov. Gamow died in 1968, more than three centuries before Hoyle, but their time in the public spotlight was approximately from the early 1950s to the mid-1960s, long enough to make their battle of ideas legendary. Their dispute involves the origin of the universe and the matter in it. Although both parties agree that the space is expanding, Hoyle argued loudly that it is infinitely old, and that new matter slowly flows into the empty space left by the expansion, creating new stars and galaxies, and filling in billions of years of void. . Therefore, in what he and co-creators Hermann Bondi and Thomas Gold call a “steady-state universe”, the universe looks basically the same as a whole over time.
On the other hand, Gamow believed that all matter was created in a hot, dense state billions of years ago, when the observable universe was much smaller. He believed that in the first few minutes, all the chemical elements were forged. Together with his colleagues Ralph Alpher and Robert Herman, he tried to show how this accumulation can take place in the cauldron of the primitive universe. Hoyle refuted the idea of large-scale destruction of the conservation of matter and energy at the time and mocked this model (including the predecessor of the Belgian mathematician and priest Georges Lemaître). In the BBC radio program in March 1949, he called such a sudden origin the “Big Bang”-the name has survived to this day.
Like Hoyle, Gamow often relied on his intuition to make scientific predictions. For projects that require page by page calculations and years of hard work, he has almost no patience. Therefore, although their views of the universe are quite different, the way they conduct research has a lot in common.
For example, when Gamov visited the University of Göttingen in 1928, he learned about the dilemma faced by physicists in explaining the alpha decay process, that is, uranium and other heavy atomic nuclei suddenly emit an alpha particle (consisting of two protons and two Clusters of protons). neutron). Obviously, alpha particles have passed through an energy barrier that is normally forbidden to pass, but how do they pass? Intuitively, this problem reminded him of a situation in quantum mechanics, in which electrons have a limited opportunity to pass through the classical forbidden zone.
Gamow used quantum rules to perform fast calculations and solved the alpha decay problem overnight. The next day he shared his results with Hungarian physicist Eugene Wigner. Later, Gamow learned that Princeton physicists Ronald Gurney and Edward Condon had independently developed similar solutions. After that breakthrough, nuclear physics has made tremendous progress. Gamow’s formula also predicts collisions between individual nuclei (protons and neutrons), which is essential for understanding how the fusion cycle converts hydrogen in the core of a vibrant star into helium, and generates heat and light in the process.
However, there is a bottleneck in the accumulation of chemical elements, and Hoyle’s insights helped to solve this bottleneck. Nature did not provide an easy way to create the isotope carbon 12 and the elements above it. The big bang nucleosynthesis-the scheme developed by Gamow, Alpher and Herman to explain how elements are forged-did not maintain a high enough temperature for a long enough time to overcome the instability of beryllium 8, which is One of the steps on the ladder reaches carbon-12. Beryllium 8 decays extremely fast, and unless the conditions are much better than those provided by the Big Bang, the chance of combining with helium 4 to form carbon 12 is very small (mathematically, this is the easiest way to produce this isotope).
Because he does not support the Big Bang, Hoyle does not believe that these chemical elements (except possibly helium) were forged in the early universe. Instead, he brilliantly concocted another method in 1946. As stars deplete their main source of fuel—converting hydrogen to helium through a process of fusion—their cores shrink and become hotter and hotter. Such a huge temperature provides a perfect environment for element creation. In addition, the sudden contraction at the end of the star’s life-if it is large enough-is accompanied by a supernova explosion, spraying forged elements into space. In short, Hoyle’s scheme cleverly explains the mixture and distribution of elements we see on Earth.
Another extraordinary insight from Hoyle explains how to overcome the beryllium 8 bottleneck. He speculated that the quantum energy level of carbon 12 matches well with the combination of beryllium 8 and helium 4, and the possibility of transformation at extremely high temperatures is sufficient to cause them to occur in the shrinking core. When a group of experimenters at the Kellogg Radiation Laboratory at the California Institute of Technology confirmed the existence of this carbon-12 excited state in nature, Hoyle’s hunch was extremely confirmed.
The disadvantage of the intuitive approach adopted by Hoyle and Gamow is that pure guesswork may deviate from the goal. In Hoyle’s case, he likes intellectual fencing and doesn’t mind if others strongly oppose his conjecture, as long as they maintain an open debate. Therefore, long after obtaining a lot of evidence, he still insisted on the changes in the steady-state model. First, in the mid-1960s, a weak radiation afterglow was discovered, which permeated the entire universe and pointed to a hot big bang.
In addition, in the last few decades of his life, he published many books and articles, and published some marginal views in areas outside his major. For example, he proposed that many diseases on the earth originated from extraterrestrials, and that a well-known and well-known fossil in the London Museum is fake-without providing credible evidence for any kind of view. Gamow did not go out in the same way. However, he often bombarded his colleagues with a series of speculative ideas, such as Edward Teller when they worked together at George Washington University in the late 1930s, most of which never landed.
In short, the intuitive method that allowed Hoyle and Gamow to propose proposals to promote scientific understanding also led them to many premonitions of nowhere to go. Hoyle, let alone Gamow, as everyone knows, he insisted on this idea for too long. Gamow will simply turn to other topics and plans. Today, as many scientific companies have become larger and more cautious, the role of these anti-traditionalists has greatly diminished. Nonetheless, we may toast the courage of past mavericks (such as Hoyle and Gamow) for the leap forward that follows.
This is an opinion and analysis article, the views expressed Author or author Not necessarily those Scientific american.