by Jonathan Lau and Dr. James Li
When we were young, we often asked why? or how? to understand the things around us. Why is the sky blue? Why do birds fly? How do rainbows form? Why? Why? Why? Sometimes, our stream of endless questions may irritate our parents, and the more impatient may finally capitulate to because that’s the way it is , or worse, because I said so . However, the keen parent, may instead recognize a teachable moment, and respond with why do you think this is happening, let’s explore…. From this initial inquiry, we may begin to form a hypothesis , which is a word derived from Greek hypo- meaning under and -thesis meaning placing, and together gives the meaning of foundation. This is a common human experience, to want to understand the foundation of our observable universe, the place we live in.
For example, playing by the ocean, you notice that a stone thrown in the ocean will sink, yet a beach-ball floats.You ask: why does the stone sink, and the beach-ball float? Well, what else floats? Curious, you attempt throwing a bunch of things into the water: various toys, a football, pieces of paper and plastic, your mom’s phone (wait stop!).
Could it be the shape? To explore this, you hypothesize that round objects float, while non-round objects sink. Yet, you immediately remember your observation that the beach ball and the stone were both round, but gave different outcomes. And, your toy tugboat floats, and it isn’t round! Hypothesis incorrect. Could it be the material? You then form the hypothesis that rubber objects float, and metallic and “hard” objects sank. You observe that most metallic objects and rocks sank, but those rubber balls did not. But you did notice that a deflated beach ball sank as well. Hrrmm… this hypothesis is also incorrect.
Could it be the weight? Hypothesis: heavy things sink, and light things float. You decide this must be it! You happily boast to your friends, who’ve been throwing things right alongside you all this while, and run gleefully to your parents to announce your breakthrough. But wait, your dad’s boat, surely is heavier than all these items you’ve been throwing in the ocean, and it floats. Hypothesis is yet again disproven.
Congratulations, you have been thinking like a scientist!
This cycle of hypothesis and experiment will continue, until you’ve come up with a hypothesis that stands the scrutiny of yourself and your friends’. Most likely, you’ll run out of things to toss, and/or your parent decides that the teachable moment has passed, and may begin guiding you towards the concept of density along with a tale of Archimedes’ Eureka moment.
In the scenario above, you:
1. observed something, became curious about it, and started asking questions;
2. formed a hypothesis to provide an explanation;
3. carried out experiments to prove or disprove your hypothesis based on evidence;
4. modified your hypothesis and experimented repeatedly, until you arrived at the correct prediction.
5. in the process, presumably, you also consulted credible sources (your parents) and that one really smart neighbour, and engaged your playmates in discussions about the accuracy and precision of your methods, all the while recording your observations in your handy notebook (you have learned your alphabet haven’t you?).
While science does have a lot of facts to memorize, especially from textbooks, the true nature of science is not memorization. Rather, the scientific method is used to fulfill that curiosity inside all of us. We take for granted the facts we memorize, but understand that it was another person, or teams of scientists just like us, that worked very hard to prove them. However, scientific facts only stay facts if other people can repeatedly confirm they get the same results, no matter if they live in Guyana, Jamaica, Haiti, Canada, China, or Antarctica! Most importantly, scientific findings must stand the test of time – does the evidence discovered centuries ago still remain true today? If I looked through a telescope pointed at Jupiter, would I still see its four moons that the father of Physics, Galileo Galilei, discovered 400 years ago? Yes, I would, except I would expect to see 63 more known smaller moons orbiting Jupiter discovered by others since then, meaning there could be more moons left to discover! This is the progress of science – discovering truth by building on previous discoveries.
The scientific method is by no means perfect. Existing tools and technologies may be insufficient to prove or disprove a hypothesis, some people lie about their evidence, some experiments are poorly designed or executed, or maybe even politics gets involved. However, at present, the scientific method is the best way for us to systematically understand the observable universe and reliably produce facts to expand on our knowledge. If scientists ever make a mistake, the great thing is that there will always be another group of scientists to challenge them. This keeps the pursuit of knowledge pure and transparent. A flaw will eventually be detected by someone curious enough to ask a question – perhaps this person will be you!