What exactly is science?

Anirban Kundu
&
Partha Ghosh

Photo by Pixabay 

 Science (from the Latin Scientia, meaning “Knowledge”) can be defined as a process that uses evidence, logic, and creativity to discover and explain natural and physical phenomena while avoiding bias. The scientific method is a method of research with defined steps that include experiments and careful observation. Science is thus the study of Nature, or gaining knowledge about Nature. That is why science was also known as Natural Philosophy. The name of Sir Isaac Newton’s famous treatise is ‘Philosophiæ Naturalis Principia Mathematica’, which in English translation reads: Mathematical Principles of Natural Philosophy. People who studied Nature were called natural philosophers; the word “scientist” was coined much later, by the British polymath William Whewell. The doctorate degree is still called a Ph.D.—Doctor of Philosophy—be it in whatever stream.

Nature includes everything – from the atoms and subatomic particles to the stars and galaxies and the whole universe, from the smallest virus and bacteria to the biggest animals. Traditionally, the broadest classification was the science of living things and the science of inanimate objects. Subjects like botany, zoology, physiology, and anthropology fall under the first category; physics, chemistry, astronomy, and geology fall under the second. However, those fields of science related to the physical world and its phenomena and processes are considered natural or physical sciences.

There is no complete agreement when it comes to defining what the natural sciences include, however, all agree that these often rely on the use of quantitative, or numeric, data although some may use qualitative, or non-numeric data to support findings.

The boundaries have become pretty fuzzy nowadays, overlapping streams have come up (like Biophysics, Biochemistry, or Paleo-Botany), and new areas have been or are being developed, like computer science and artificial intelligence. One may expand the ambit further and include subjects like psychology, economics, or social sciences, but semantics won’t serve our purpose. So, let us stick to the definition of science given in the Oxford dictionary: The systematic study of the structure and behavior of the physical and natural world through observation, experimentation, and the testing of theories against the evidence obtained.

There are several important words and phrases in that definition: systematic study, structure and behavior, observation, experimentation, testing of theories, evidence obtained, etc. In the rest of the note, we will try to elaborate on them. As this is part of a physics syllabus, almost all the examples will be chosen from physics.

Fact:

“When you drop a pencil, it falls to the ground”

This one is pretty straightforward, but it's got a big caveat. In science, a fact is an observation that's been confirmed so many times that a scientist can, for all intents and purposes, accept it as true. But everything in science comes with a level of uncertainty, so nothing is ever scientifically "true" beyond a shadow of a doubt. You could say that "all swans are white" is a fact, but there's always the chance you could see a black swan and throw that fact out the window. Likewise, you could say it's a fact that every time you let go of a pencil, it will drop to the floor, but science leaves room for the vanishingly, infinitesimally small chance that it might not.

Hypothesis:

“A pencil drops because there's a force pulling it down.”

A hypothesis is a tentative explanation of an observation that can be tested. It's just a starting point for further investigation. Any observation usually comes with an array of hypotheses. If you observe that a swan is white, your hypothesis could be that it's painted, or it was bleached by the sun, or its feathers just lack pigment. You can then investigate all of those hypotheses and come away with the one that's most supported by the evidence, if any. Throughout history, there have been many hypotheses about why things fall when you drop them. Aristotle believed it was because material objects had a tendency to fall toward the center of the universe, which the ancient Greeks believed was Earth. Newton reasoned that all Earth-bound objects must be attracted to Earth, but also, all planets must be attracted to other planets, and so on with every object in the universe. His hypothesis was that this all happened through a force of attraction that he called gravity.

Law:

“Any particle of matter in the universe attracts any other with a force varying directly as the product of the masses and inversely as the square of the distance between them”

You might expect ‘theory’ to be the next natural step in this path to scientific truth (and to be fair, we did kind of prime you for that with the headline), but you'd be wrong. That's not to say a law is inferior to a theory; it's just a different thing altogether. In science, a law is a detailed description of how some aspect of the natural world behaves, usually involving math. Newton's law of universal gravitation, as quoted above, describes the way matter behaves with impressive precision. It makes it easy to predict how a moon will act if it's very big and close to its planet versus very small and far away. But how is all it describes — it doesn't explain why.

Theory:

“Mass and energy cause space-time to curve, and the force of gravity arises from the curvature of space-time”

A theory is an explanation of some aspect of the natural world that's well-substantiated by facts, tested hypotheses, and laws. Quoted above is a simplified version of Einstein's general theory of relativity. Newton said that two objects attract based on how massive they are and the distance between them; Einstein said this happens because the mass of each object literally distorts the fabric of the universe, and the greater the mass, the greater the distortion. A theory is thus the granddaddy of all scientific statements, which is why it makes no sense to say that it is "just a theory", as it has passed the toughest tests that we can throw at it. But as we said, science never says anything with 100 percent certainty. Einstein's theory breaks down when you apply it to quantum mechanics, which deals with the behavior of tiny subatomic particles. As a result, many scientists are throwing new hypotheses about gravity into the ring. But that doesn't mean Einstein was wrong. General relativity explains the vast majority of our observations, and every time scientists have tried to prove it wrong, they've failed. That's the strength of a scientific theory: It's built on a sturdy enough foundation that even if you find a few cracks in it, you can trust that the structure as a whole will remain standing.

The steps of the scientific method will be examined in detail later, but one of the most important aspects of this method is the testing of hypotheses by means of repeatable experiments. It is relatively easy to apply the scientific method to disciplines such as physics, chemistry & life sciences, but for disciplines like paleontology and geology, the scientific method is adapted to the field of study.

Any hypothesis may be found to be correct or false through continued support or contradictions from other findings. It may become a theory with time and evidence. A theory is a well-tested and confirmed explanation for observations or phenomena. Science may be better defined as fields of study that attempt to comprehend the physical and natural underpinnings of the universe.