Science is a systematic and logical approach to discovering how things in the universe work. It is derived from the Latin word “scientia,” which translates to knowledge. Unlike the arts, science aims for measurable results through testing and analysis. Science is based on fact, not opinion or preferences. The process of science is designed to challenge ideas through research. It is not meant to prove theories, but rule out alternative explanations until a likely conclusion is reached.
The scientific method
When conducting research, scientists observe the scientific method to collect measurable, empirical evidence in an experiment related to a hypothesis (often in the form of an if/then statement), the results aiming to support or contradict a theory.
The steps of the scientific method go something like this:
- Make an observation or observations.
- Ask questions about the observations and gather information.
- Form a hypothesis — a tentative description of what’s been observed, and make predictions based on that hypothesis.
- Test the hypothesis and predictions in an experiment that can be reproduced.
- Analyze the data and draw conclusions; accept or reject the hypothesis or modify the hypothesis if necessary.
- Reproduce the experiment until there are no discrepancies between observations and theory.
Some key underpinnings to the scientific method:
- The hypothesis must be testable and falsifiable.
- Research must involve deductive reasoning, not inductive reasoning. Deductive reasoning is the process of using true premises to reach a logical true conclusion.
- An experiment should include a dependent variable (which does not change) and an independent variable (which does change).
- An experiment should include an experimental group and a control group. The control group is what the experimental group is compared against.
Scientific theories and laws
The scientific method and science in general can be frustrating. A theory is almost never proven. A few theories do become scientific laws (such as the law of gravity) and laws are generally considered to be without exception — though in fact even some laws have been modified over time after further testing found discrepancies.
This does not mean theories are not meaningful. For a hypothesis to become a theory, rigorous testing must occur, typically across multiple disciplines by separate groups of scientists. Saying something is “just a theory” is a lay person’s term that has no relationship to science, because in science, a theory is something that is very well supported by observation and experimentation.
A brief history of science
The earliest evidence of science can be found in prehistoric times, from the discovery of fire, invention of the wheel and development of writing. Early tablets contain numerals and information about the solar system. Science became decidedly more scientific over time, however.
1200s: Robert Grosseteste develops the framework for the proper methods of modern scientific experimentation, including the principle that an inquiry must be based on measurable evidence that is confirmed through testing.
1400s: Leonardo da Vinci begins his notebooks in pursuit of evidence that the human body is microcosmic. The artist, scientist and mathematician also gathers information about optics and hydrodynamics, but none of his scientific works are ever published.
1500s: Nicolaus Copernicus advances the understanding of the solar system with his discovery of heliocentrism, the model in which the Earth and planets revolve around the sun, which is the center of the solar system.
1600s: Johannes Kepler builds upon these observations with his laws of planetary motion. Galileo improves on a new invention, the telescope, and uses it to study the sun and planets. The 1600s also saw advancements in the study of physics as Isaac Newton developed his laws of motion.
1700s: Benjamin Franklin discovers that lightning is electrical. He also contributes to the study of oceanography and meteorology. The understanding of chemistry also evolves during this century as Antoine Lavoisier, dubbed the father of modern chemistry, develops the law of conservation of mass.
1800s: Milestones include Alessandro Volta’s discoveries regarding electrochemical series, which leads to the invention of the battery. John Dalton also introduces atomic theory, which states that all matter is composed of atoms that combine to form molecules. The basis of modern study of genetics advances as Gregor Mendel unveils his Mendel's laws of inheritance. Later in the century, Wilhelm Conrad Röntgen discovers X-rays. George Ohm’s Ohm’s law provides the basis for understanding how to harness electrical charges.
1900s: The discoveries of Albert Einstein, who is best known for his theory of relativity, dominate the beginning of the 20th century. Einstein's theory of relativity is actually two separate theories. His special theory of relativity, which he outlined in a 1905 paper, "The Electrodynamics of Moving Bodies," concludes that time must change according to the speed of a moving object relative to the frame of reference of an observer. His second theory of general relativity, which he published as "The Foundation of the General Theory of Relativity" in 1916, advances the idea that matter causes space to curve.
2000s: The 21st century sees the first draft of the human genome completed, leading to a greater understanding of DNA and advancing the study of genetics and its role in human biology and as a predictor of diseases and other disorders.