Science definition: finding out how the world works, and checking

Science definition: four common senses

1. A way of knowing. The process of asking questions about nature, making predictions and testing them with careful observation or experiments.
2. A body of knowledge. What we have learned this way: "Science tells us the Earth orbits the Sun."
3. A subject or field. Biology, chemistry and physics are sciences; so, in a wider sense, are economics and psychology.
4. A precise skill. In casual speech: "Making the perfect cup of tea is a science."

Asked to define science in one breath? Try this: learning about the world by testing ideas against evidence.

How science works in practice

Here is the science meaning put into action. Researchers use many methods, but most follow a loop often called the scientific method:

1. Observe something and ask a question.
2. Suggest a possible explanation, a hypothesis.
3. Make a prediction that could prove the idea wrong.
4. Test it with an experiment or careful observation.
5. Analyse the results and share them so others can check and repeat the work.

A key feature is that conclusions stay open to change when better evidence appears.

Branches of science

People debate whether formal and social sciences belong under the same label, since maths does not rely on experiments and human behaviour is hard to test in a lab.

Where the word came from

Fourteenth century English took science from an Old French word rooted in Latin scientia, knowledge, from scire, to know. At first it meant knowledge of any kind, including book learning and even a craft or trade. Through the 1600s and 1700s, what we now call natural science was often called natural philosophy. By the mid 1800s the main modern sense, the study of the natural and physical world, had taken over, and the word scientist was coined in the 1830s to name people who do it. The older link with philosophy still shows in the title Doctor of Philosophy for research degrees.

Science, pseudoscience and belief

What separates science from other ideas is testing. A scientific claim must make predictions that evidence could show to be false. Claims that cannot be tested this way, or that ignore evidence against them, are often called pseudoscience. Science also differs from religious faith: it answers questions about how the natural world works, while many people turn to faith for questions of meaning and value. Plenty of scientists are religious, and many see the two as answering different kinds of question.

Using science and scientific

Science is usually uncountable for the general idea ("a love of science") and countable for fields ("the life sciences", "a new science"). Common phrases: science fiction, rocket science (used jokingly for anything hard: "it is not rocket science"), blinding with science (confusing people with jargon) and down to a science. The adjective is scientific and the person is a scientist. The science and ideas section collects many related terms you will meet in class.