THE SCIENTIFIC METHOD

What is science? How is it different from other ways of thinking? and what are scientists like? How do they think and what do they mean when they talk about doing science? Science isn't just test tubes or strange apparatus. And it's not just frog dissections or names of plant species. Sciences is way of thinking, a vital, ever-growing way of looking at the world. It is a way of discovering how the world works a very particular way that uses a set of rules devised by scientists to help them also discover their own mistakes.

Everyone knows how easy it is to make a mistake about the things you see or hear or perceive in any way. If you don't believe it, look at the two horizontal lines on the previous page. One looks like a two way arrow; the other has the arrow heads inverted. Which one do you think is longer (not including the arrow heads)? Now measure them both. Right: They are exactly the same length. Because it's so easy to go wrong in making observations and drawing conclusions, people developed a system, a scientist method,  for asking How can i be sure? If you actually took the time to measure the two lines in our example, instead of just taking our word that both lines are the same length, then you were thinking like a scientist. You were testing your own observation. You were testing the information that we had given you that both lines are exactly the same length. And you were employing one of the strongest tools of science to do your test: You were quantifying, or measuring, the lines.

Some 2.400 years ago, the Geek philosher Aristotle told the world that when two objects of different weights were dropped from a height the heaviest would hit the ground first. It was a common sense argument. After all, anyone who wanted to try test could make an "observation" and see that if you dropped a leaf and stone together the stone would land first. Try it yourself with a sheet of notebook paper and a paperweight in your living room. Not many Greeks tried such a test, though. Why bother when the answer was already known? And, being philosophers who believed in the power of the human mind to simply reason such thing out without having to resort to tests, they considered such an activity to be intellectually and socially unacceptable.

Centuries later, Galileo Galilei, a brilliant Italian who liked to figure things out for himself, did run some tests. Galileo, like today's scientists, wasn't content merely to observe the objects falling. Using two balls of different weights, a time keeping divice, and an inclined plane, or ramp, he allowed the balls to roll down the ramp and carefully measured the time it took. And he did this not once, but many times, inclining planes at many different angles. His results, which still offend the common sense of many people today, demonstrated that, if you discount air resistance, all objects would hit the ground at the same time. In a perfect vacuum (which couldn't be created in Galileo's time), all objects released at the same time from the same height would fall at the same rate. You can run a rough test of this yourself (although it is by no means a really accurate experiment), by crumpling the notebook paper into a ball and then dropping it at the same time as the paperweight.

Written By Ray Spangenburg and Diane K. Moser (The History Of Science From 1946 to The 1990s)