In physics class last week, as our teacher was lecturing, she presented a very complex, sophisticated equation to us. One student asked her: “So how was this equation derived?” Our teacher, perhaps didn’t want to waste time, or just simply didn’t know the answer herself, responded: “You don’t need to know how to derive this equation, it’s not in our syllabus. You just need to memorise it and apply it to problem-solving.” And in that moment, I thought, “Don’t we need to understand how concepts were proved to actually internalise knowledge that we are learning?” Or, where is the evidence that can corroborate these equations and concepts?

This event led me to a knowledge question—to what extent is knowledge in natural sciences absolute? When we open our science textbooks or listen to teachers’ lectures in class, we tend to believe all the equations and concepts that are fed to us. Do you ever question the validity of the concepts and ideas that we learn? Or, in other words, is knowledge in sciences completely reliable?

Scientific knowledge is created through a continuous process, one which we call the hypothetico-deductive method. The process in which knowledge is created begins with a question and evolves into a specific hypothesis. Scientists then design an experiment; and through observation and rigorous analysis, a conclusion that either corroborates or refutes the original hypothesis is reached. Not only does the proposed idea have to undergo such testing, others will also try to replicate the experiment and prove it wrong. If others’ replications turn out to have different results, the idea will be called into question. So if you wonder why people believe in the validity and authority of scientific knowledge, as you can see, the scientific method allows very little room for errors. And if misjudgements are made, under rigorous testing and peer reviews, scientific knowledge will self-correct itself.

But does this mean that scientific knowledge is always entirely correct? The scientific method certainty seems so, but history would prove otherwise. For instance, paradigm shifts in the natural sciences happen quite often throughout history. In the 16th century, the transition in cosmology from the Ptolemaic view to the Copernican view is one example of a paradigm shift, and the development of quantum mechanics that replaced classical mechanics in the early 20th century illustrates another. A paradigm is a “system of concepts, language, assumptions, methods, values, and interests that define scientific research,” or, it is simply a model that people perceives as ‘right’. However, Thomas Kuhn, an American historian of science, claims that paradigms are often challenged by new ideas. Under paradigms, normal science operates. But when anomalies arise, they challenge the theoretical framework and the current paradigm is no longer sustainable. Then, a period of revolutionary (abnormal) science emerges as new theories seek to replace the old paradigm. Eventually, one of these theories becomes the new orthodoxy and a new cycle begins. This cycle proves that scientific knowledge is indeed not absolute; it has a dynamic nature and advances through a series of perpetual revolutions. 

Natural sciences progress through new observations, and new ideas can sometimes prove earlier theories wrong. But why are we so taken aback when a scientific theory is proved wrong? It is because we rely on conventions. Conventions, such as electric currents flow from the positive end of a cell to the negative end, establish standards ways that allow people to communicate and share scientific knowledge; and when they are challenged, or even overthrown, confusions and chaos may arise. As people get so used to the conventions in natural sciences, they have a hard time accepting uncertainty and change. It is hard anyone to discover and accept what he or she fervently believed in is actually false.

When scientists try to prove new theories, the rely heavily on reason, both empirical—relying on observation—and rational—relying on logic and reasoning. We tend of think of science as a form of authority that is always logical and always true. But other than reasoning, what other ways of knowing do scientists use to prove new ideas? Well, all the other ones as well. Imagination, because we need to come up with hypotheses; emotion, because what leads to scientific breakthroughs is inquiry. And what drives inquiry? Interest and curiosity.

Another major factor that drives the creation of new scientific theories is faith; and because of faith, science may not be absolute. Just because evidence can be gathered to prove a hypothesis, it doesn’t necessarily mean that the evidence can apply to all situations. Faith gaps the bridge between evidence and conclusion that we draw. And that is what takes away the perceived absolutism in scientific generalisations—people can devise new experiments that refute the existing theories. Karl Popper, a leading political philosopher, claims that: “energies of science should be devoted to disproving universal statements rather than proving them.” This idea gave birth to falsificationism, which aims to prove prevailing paradigms invalid. Scientific knowledge is dynamic, it certainly evolves over time as new ideas emerge. 

So next time when someone tries to feed you an idea, ask yourself, where is the evidence to prove it true? Or, better yet, how can you prove it wrong?