What distinguishes Science from Non-Science

The scientific Method

What distinguishes science from non-science?

This may seem like a silly question at first, but it is one that has been debated for many centuries. Science has made an immense contribution to our world. The science tag commands authority and respect and can attract financial gains. There is an incentive for some people to pose as scientists and claim that their ideas or products are ‘scientifically proven’ without merit. Here we explore what is science or non-science, it may seem obvious but close to the boundary the lines may be a little more blurred.

Merriam-Webster defines science as “knowledge or a system of knowledge covering general truths or the operation of general laws especially as obtained and tested through scientific method”. This is a pretty wordy definition, but the key part of it is the term “scientific method”.

The scientific method as we know it today is a series set of steps. You observe something you can’t explain, form a hypothesis, which means coming up with a plausible explanation, and then conducting experiments to support the hypothesis. The data gathered from these experiments helps to form a conclusion. 

Yet this definition is still not specific enough, as was demonstrated by the phrenologists of the 18th century. Phrenology was a “science” that measured the mental traits of individuals using the shape of their skulls. The principle was that the brain could be separated into anywhere between 27 and 40 parts, each with their own distinct functions. The relative sizes of those sectors represented how competent an individual was in the functions they were associated with.

Since the shape of the skull is determined by the shape of the brain, phrenologists predicted the characteristics of a person’s mind simply by feeling their head. Some traits they searched for were wit, self-esteem, aggression, and generosity. According to phrenology, a person with a large forehead was bound to be intelligent, as the sector responsible for reasoning was located at the front of the brain.

However, a major blow was struck to Phrenology by a researcher named William Hamilton. Phrenologists predicted that a part of the brain known as the Cerebellum is responsible for sexual activity. They concluded that men experience sexual arousal more often and more easily than women because men have a larger cerebellum.

Yet, Hamilton discovered that women were the ones with a larger cerebellum. Today, we know that Hamilton’s measurements were wrong, and women do have a smaller cerebellum, but the phrenologists at the time did not respond by conducting their own experiments. Instead they defended phrenology claiming the best they could do was make estimates, and that the true science was based on the “bumps” felt by the phrenologist’s hands. 

This revealed a fundamental flaw in phrenology as a science. When its truth and authority were threatened, the phrenologists resorted to offering excuses for phrenology’s shortcomings. Their theories were not based on facts and could not be verified through experiments as the response to a contrary observation was to move the goal posts. While phrenology was dismissed as non-science, there was still no clear thinking at that time as to what constitutes science.

Perhaps the best attempt to tackle this issue was made by a famous philosopher of the 20th century named Karl Popper. Popper was familiar with the theories of Marxism, and believed it to be a scientific theory. Marx had made observations and predicted that eventually the working class would revolt against the existing capitalist systems and establish communist nations.

Decades after the death of Marx, the workers had not yet revolted. The global wealth gap had seemingly worsened, but communism was nowhere in sight. Regimes were not controlled by the working class. Marxists offered explanations, stating that the workers lacked class consciousness, and that Marx’s predictions were still valid.

Popper was bothered by this sort of reasoning. According to the Marxists, Marxism was true regardless of whether the revolution occurred or not. There was no way to disprove the initial theory. Karl Popper believed that any good scientist must at least let themselves be disproven, and in his opinion, Albert Einstein was the embodiment of this idea.

Karl Popper’s introduction to Einstein was one of the great physicist’s lectures on special relativity conducted in Vienna. Popper was amazed by the distinction between Einstein and the Marxists of his time. Einstein was making bold predictions that contradicted Newtonian physics. If Einstein’s predictions failed, his entire theory of relativity would fall apart. This “risky” nature of Einstein’s approach to science appealed to Karl Popper.

Thus, the risk of being wrong became the metric that Popper would use to separate science from Pseudoscience. He stated that a theory is scientific if it risks being disproved by an experiment that contradicts its predictions. This principle is called “falsification”, so if a prediction can be falsified, it is scientific.

In Einstein’s case, his theory of relativity predicted that gravity could deflect rays of light. This was proven in 1919 by a British physicist named Arthur Eddington, who was not directly associated with Einstein. Yet, if Eddington had observed that the light from far-away stars was not deflected by the sun, Einstein would have been proven wrong. 

While falsification now serves as an effective filter to separate science from pseudoscience, it is also a driver of scientific innovation. This is because science consists of forming explanations for natural phenomena. Thus, new theories are required when old theories are falsified. Certain scientific experiments can be defined as tools for falsification. 

One of the best examples of the use of falsification to develop new theories is something we all learned in high school: The structure of the atom. In the 1800s, scientists had believed for many years that matter was made up of atoms, but they did not know what an atom looked like. The first person to put forward a theory backed by science was J. J. Thomson.

Thomson had discovered the electron in 1897 through his experiments with cathode rays. He suggested a structure for the atom which some referred to as the “plum pudding model”. The “pudding” was a cloud of positive charge, with electrons embedded in it like little plums. 

Thomson had a student named Ernest Rutherford, who aimed to test his professor’s predictions. Rutherford’s gold foil experiment involved researchers firing positively charged “Alpha particles” at a thin sheet of Gold. If Thomson was correct, the Alpha particles would pass through the “pudding” undeflected. But the Gold foil experiment showed a small fraction of the particles being deflected by over 90 degrees. Some of them bounced off the foil right back in the direction of the source.

Thus, Thomson's model was falsified and Rutherford predicted a new atomic model. The mass of an atom had to be concentrated at the centre in a “nucleus”. The nucleus would account for only a tiny portion of the volume of an atom, but it would contain nearly all of the atom’s mass. Rutherford predicted that an atom would be mostly empty space, with the electrons surrounding the nucleus being held in place by electrostatic forces.

Many improvements, such as predicting the specific positions where an atom’s electrons reside, have been made to Rutherford’s model. Currently, the prevailing theory that predicts the behaviour of subatomic particle is quantum mechanics; the electron is both a wave and a particle, whose domain around an atom is probabilistic and could be described as dumbbell shaped. Quantum mechanics is one of the most testable scientific theories ever created and has passed many scientific inquiries. However, physics has been in a quandary in that its two main theories quantum mechanics the theory of tiny particles and general relativity the theory of gravity and large particles are philosophically incompatible; each theory does not provide useful predictions for each other’s domains and there has been a drive towards a theory of everything, one theory that can explain everything. Physicists are understandably uncomfortable with having two main universal but incompatible theories; in some way this might seem like moving goal posts for each other theories as they both purport to be theories of everything, but another question is does quantum mechanics make predictions that contradicts general relativity and vice versa; general relativity fails on a small scale where the uncertainty of position of small particles is predictive and as for quantum mechanics on a large scale, we know from the Schrodinger’s cat thought experiment that we do not get superposition of large objects.

Physics may distinguish itself from other sciences, in that it has a universal outlook in its scope; it sets itself in the most perilous position of creating theories of the widest scope and testability with the most opportunities for contradiction. Much of this stems from Newton’s thinking. Before he postulated his laws, he started with the notion that the laws would govern every object in the universe no matter how big or small, without exception and this is something that we largely still believe today. Such is the scope of physics that it interacts with or underpins almost every other science. Relativity superseded Newton’s laws as it could explain everything that was experimentally observed in support of Newton’s laws and the observation’s that contradicted Newton’s laws at the time; the absoluteness of the speed of light in a vacuum regardless of the motion of the observer. It also created many other postulates that could be tested in favour of Relativity rather than Newton’s laws.

It is remarkable that so many scientific theories seem quite elegant, this is an unwritten law of science, that a theory makes many testable predictions but the theory itself should have limited degrees of freedom otherwise it could be compatible with all observations, so the more elegant and simpler the theory the more remarkable the theory is. You might think that physics would be immune from this as it provides huge scope for observations and testability, but one of the leading theories of everything, string theory, has more recently come under scrutiny as currently it does not produce any new testable observations, though this may change in the future. One of the problems with string theory, that has been pointed out, is that it postulates 10 dimensions but 6 of these dimensions have to be removed to bring about our observable world¹. However, the number of ways of removing these dimensions is practically infinite, leading to some to regard string theory as more of a philosophy, appealing though it may be, rather than a scientific theory and even for some proponents to argue that its elegance rather than the empirical support for its postulates, should be sufficient to elevate it to a scientific theory, which is contrary to the scientific process.

The scientific process means being open to the evidence, that any theory is held tentatively as new evidence may arise that contradicts the theory. We are making observations now that we couldn’t have made in the past due to technological progress. The science which underpinned these technologies may succumb to contrary observations yielded by the technology that it produced. In this way no theories are true, they will always be usurped at some time in the future. This does not mean that they weren’t useful. If contrary observations are accrued then a scientific theory is not discarded instantly as it needs to be replaced by a superior theory, but if one does not exist then we still need the prevailing theory as we still benefit form the observations that it predicts and its framework of thinking and philosophy. Such a theory is better than no theory all, though we know it is not perfect, but we try and find some better explanation, elusive that it may be. If we simply ignore the evidence to the contrary, redefine the language or move the goal posts (increasing the degrees of freedom), then we are departing from science.

References

 1) Why String Theory Is Not A Scientific Theory (forbes.com)