We live in a scientific age. Millions of young people study science, thousands of universities teach it, and hundreds of publications chronicle it. We even have a cable channel devoted exclusively to its wonders. We are immersed in technology rooted in its discoveries. But what is science, and who was its first practitioner?
Science is the study of the physical world, but it is not just a topic, a subject, a field of interest. It is a discipline–a system of inquiry that adheres to a specific methodology–the scientific method. In its basic form, the scientific method consists of seven steps:
2) statement of a problem or question;
3) formulation of a hypothesis, or a possible answer to the problem or question;
4) testing of the hypothesis with an experiment;
5) analysis of the experiment’s results;
6) interpretation of the data and formulation of a conclusion;
7) publication of the findings.
One can study phenomena without adhering to the scientific method, of course. The result, however, is not science. It is pseudoscience or junk science.
Throughout history, many people in many parts of the world have studied nature without using the scientific method. Some of the earliest people to do so were the ancient Greeks. Scholars such as Aristotle made many observations about natural phenomena, but they did not test their ideas with experiments. Instead they relied on logic to support their findings. As a result, they often arrived at erroneous conclusions. Centuries later the errors of the Greeks were exposed by scholars using the scientific method.
Perhaps the most famous debunking of Greek beliefs occurred in 1589 when Galileo Galilei challenged Aristotle’s notions about falling bodies. Aristotle had asserted that heavy bodies fall at a faster rate than light bodies do. His contention was logical but unproven. Galileo decided to test Aristotle’s hypothesis, legend says, by dropping cannon balls of different weights from a balcony of the Leaning Tower of Pisa. He released the balls simultaneously and found that neither ball raced ahead of the other. Rather, they sped earthward together and hit the ground at the same time. Galileo also conducted experiments in which he rolled balls of different weights down inclines in an attempt to discover the truth about falling bodies. For these and other experiments, Galileo is considered by many to be the first scientist.
Galileo was not the first person to conduct experiments or to follow the scientific method, however. European scholars had been conducting experiments for three hundred years, ever since a British-born Franciscan monk named Roger Bacon advocated experimentation in the thirteenth century. In Part Five of his Opus Magus Bacon challenges ancient Greek ideas about vision and includes several experiments with light that include all seven steps of the scientific method.
Part Five of Opus Magus is not an original work, however. It is a summary of a much longer work entitled De aspectibus (The Optics). Bacon follows the organization of De aspectibus and repeats its experiments step by step, sometimes even word for word. But De aspectibus is not an original work, either. It is the translation of a book written in Arabic entitled Kitab al-Manazir (Book of Optics). Written around 1021, Kitab al-Manazir predates Roger Bacon’s summary of it by 250 years. The author of this groundbreaking book was a Muslim scholar named Abu Ali al-Hasan ibn al-Hasan ibn al-Haytham.
Born in Basra (located in what is now Iraq) in 965, Ibn al-Haytham–known in the West as Alhazen or Alhacen–wrote more than 200 books and treatises on a wide range of subjects. He was the first person to apply algebra to geometry, founding the branch mathematics known as analytic geometry.
Ibn al-Haytham’s use of experimentation was an outgrowth of his skeptical nature and his Muslim faith. He believed that human beings are flawed and only God is perfect. To discover the truth about nature, he reasoned, one had to allow the universe to speak for itself. “The seeker after truth is not one who studies the writings of the ancients and, following his natural disposition, puts his trust in them,” Ibn al-Haytham wrote in Doubts Concerning Ptolemy, “but rather the one who suspects his faith in them and questions what he gathers from them, the one who submits to argument and demonstration.”
To test his hypothesis that “lights and colors do not blend in the air,” for example, Ibn al-Haytham devised the world’s first camera obscura, observed what happened when light rays intersected at its aperture, and recorded the results. This is just one of dozens of “true demonstrations,” or experiments, contained in Kitab al-Manazir.
By insisting on the use of verifiable experiments to test hypotheses, Ibn al-Haytham established a new system of inquiry–the scientific method–and earned a place in history as the first scientist.