The Embarrassing Menagerie – Part One
As we have seen, the classical view expressed by scientists at the end of the nineteenth century was that the universe was an objective reality that operated in accordance with fixed laws that could be expressed in mathematical terms. In short, the commonly accepted view of science was then, as it still is today, that the world of objects that we see around us conforms exactly to the world that is revealed to us by our senses.
As our senses confirm, the majestic oak tree standing tall in its meadow leaves us in no doubt that the tree exists as a solid, physical object that has an existence entirely separate from ourselves. We not only see the tree, but we can touch, taste and smell it, and listen to the rustle of its leaves. Its objective reality is self-evident. The idea that this gigantic tree could be an illusion, a subjective projection in consciousness, seems patently ridiculous.
Yet within a few decades of the onset of the twentieth century, this classical concept of the world as a Giant Machine had been demolished. This monolith of science, so carefully crafted over the centuries by such intellectual giants as Copernicus, Galileo, Kepler, Newton and others has been found to be illusory. Upon closer investigation, our so-called “real” world has been found to be unreal, and our apparent “objective” world as revealed to us by our senses has been found to be subjective. At best it can only be described as a projection of the mind.
The path leading to this extraordinary conclusion began with the quest to find the ultimate building blocks of matter. Some five centuries before the birth of Christ, Greek philosophers had attempted to discover the fundamental nature of matter. The Athenian Democritus considered that all substances could be broken down into an enormous number of very small particles that were all alike. These microscopic particles were thought to be indivisible, and were referred to as “atoms”.
Almost twenty-two centuries were to pass before the idea that matter was composed of basic units or atoms was again advanced by science. While Robert Boyle theorized that all substances were comprised of tiny, irreducible units, it was John Dalton who suggested that every element was composed of identical atoms that were unique to that element. He further theorized that chemical reactions could be explained by different atoms combining in different ways, and that all chemical compounds were simply combinations of different kinds of atoms.
Up until that time it was generally believed that atoms were units of matter that could not be broken down any further. It was not until the end of the nineteenth century that suspicion began to grow that the atom may not be indivisible after all, and that it might be capable of being broken down into even smaller particles. The investigation into these smaller particles had to wait until the twentieth century, when the technology of science was sufficiently advanced to enable scientists to explore the internal structure of the atom.
It was the British physicist J.J. Thomson who established in 1897 that atoms of elements contained positive as well as negatively charged particles, and that these charged particles were held together by the force of electricity. Thomson was the first to recognize that because the atoms that existed freely in nature were electrically neutral, each atom must contain an equal number of negatively and positively charged particles.
Thomson called the negatively charged particles “electrons”, and the positively charged particles “protons”. It was not exactly clear to him how these two types of particles co-existed together inside the atom, but he thought that they would probably be spaced together at random intervals, much like seeds inside a watermelon. So at the dawn of the twentieth century, the atom was considered to be a sort of solid pudding with smaller protons and electrons embedded within it.
It was during this period that a French physicist Henri Becquerel noticed an odd phenomenon. He found that certain chemical substances gave off spontaneous rays of energy, in a process which became known as radioactivity. For this discovery he was to become one of the earliest recipients of the Nobel prize. Because certain unstable elements like radium and uranium gave off rays of tiny, high-speed particles called alpha particles, Becquerel deduced that these particles must be part of the contents of these bulky atoms.
It was at this time that a New Zealand born physicist named Ernest Rutherford had been trying to find a way to investigate the inner nature of the atom. On learning of the existence of these alpha particles, it occurred to him that they might be a tool to enable him to prise open the secrets of the atom. He realised that these alpha particles could be fired at other atoms, like bullets from a gun, and that the resulting scattering of particles would help him understand more about the inner workings of the atom.
Rutherford was thus the pioneer of an entirely new way of investigating matter, for he began a process of scattering experiments that has continued to this day, with greater and greater degrees of sophistication. Rutherford devised an experiment in which he fired positively charged alpha particles at a thin plate of gold foil. The results of this experiment demonstrated beyond doubt that the previous concept of the atom was incorrect.
Rutherford proved via his experiment that the positive electrical charges (protons) were concentrated in the very center of the atom, while the negatively charged particles (electrons) circled around the outside of the atom. The former model proposed by Thomson, in which protons and electrons were randomly mixed inside the atom, now gave way to a new planetary model.
In Rutherford’s new concept of the atom, the nucleus was thought of as a tiny sun, with the electrons orbiting around it, much like the planets orbit around the sun. This planetary model had great esthetic charm, for it suggested that nature’s plan in the heavens was duplicated in its tiniest constituents of matter. Although this planetary concept of the atom has long since found to be incorrect, it remains to this day the way in which physicists visualise the inner structure of the atom.
Yet within a few short years this elegant model of the atom was shattered, to be replaced by something that was not only impossible to visualize, but also impossible to understand. In short, the investigation of matter had begun to lead physicists into the marshy ground of mysticism, as we shall see from the following instalments.
