What is science? It’s the methodical investigation of the natural world. Here, a geologist obtains a sample of molten lava. Image via Bob Tilling/ USGS (PDM 1.0).
Science is a way to learn about the world with objective, methodical, repeatable investigations of nature (animals, rocks, stars, viruses, weather), or anything in the natural world.
Scientific discoveries beget more science. Scientists update their previous conclusions as more data become available.
The word scientist usually means someone who has a job doing science. But anybody can carry out scientific investigations. You can, too.
What is science?
Science is a way of learning about the natural world through objective, methodical, repeatable investigations of things that can be studied and measured.
And science constantly evolves. That’s because recent discoveries raise new questions. And then, scientists revise their previous conclusions as new data emerge.
So a scientist is usually someone whose job involves doing science, as in, investigating the natural world using the scientific method.
Science covers many topics
Some kinds of scientists include:
Astronomers
Biologists
Chemists
Geologists
Physicists
But anyone can do science. If you make careful observations, write down your results, and test your ideas against evidence, you’re doing science.
So science boils down to people observing, questioning, testing and refining ideas over time.
What does science do for us?
Some knowledge gained through science has brought us:
Medical breakthroughs, such as antibiotics and vaccines
Phones, satellites, GPS and worldwide communication
A deeper knowledge of our planet and the splendors of the universe
Read more at UC Berkeley’s What has science done for you lately?
Then there’s the scientific method
Curious people have been studying nature for thousands of years. But the modern concept of science as we know it began about 300 years ago. Its foundation is the scientific method. Here are the scientific method steps:
1. Ask a question
Science often begins with a question or an observation that leads to a question:
“What is the speed of light?”
“Some stars dim and brighten regularly. Why?”
2. Research
Check what others have already discovered. Do existing theories match the evidence? Do some factors not fit the theories?
3. Form a hypothesis
If no existing theories match the evidence, your next step is to develop a hypothesis. A hypothesis is an idea that could explain the evidence. It must be objective and falsifiable.
Objective: based on evidence rather than personal opinions.
Falsifiable: can be proved wrong.
4. Test the hypothesis
Do experiments (generating new data with careful measurements) or observations (studying existing data) bear out your hypothesis?
Scientists keep detailed records, as this graph of the light output of the variable star Delta Cephei shows. Image via Wikipedia (CC BY-SA 3.0).
The scientific method continued
5. Report your results
Next, publish your results in a scientific journal. Before publication, the paper goes through peer review. Others in your field check to make sure you understand existing basic knowledge and whether your methods are sound, your results complete and your references pertinent.
6. Replication by others
Science has to be reproducible. If other scientists testing your hypothesis get the same outcomes, it’s accepted. A hypothesis that can’t be tested by others isn’t science.
7. Hypothesis becomes theory
If a hypothesis consistently holds up and explains observations well, it can become a theory. In science, the word “theory” is stronger than in ordinary use. For instance, the theory of relativity and the theory of continental drift are both universally accepted.
Why scientific conclusions change
Scientific understanding improves over time. Even universally accepted theories may eventually be revised or replaced if new evidence comes along, as in the case of Newtonian and Einsteinian physics.
Sometimes revised theories fit the data better than the old ones. Or the new theory might expand on an old one that still holds in limited areas. Newton’s laws explain gravity and inertia very well, but aren’t quite complete. Einstein’s theory of relativity filled in the blanks.
Science is always evolving. Some people are confused when scientists update their conclusions. But that’s how science works. It’s a process of homing in on – or expanding – knowledge.
So, after many years with no contrary evidence, a theory can become “settled science.” At that point, scientists consider it a solid base for a field of study, as evolution is to biology and plate tectonics to geology.
Can there be problems with science?
Sometimes scientists make mistakes. An early researcher counted human chromosomes wrong and said there were 48. People believed this for decades until somebody else counted them again, finding there are 46. This is an example of a mistake that better science corrects later.
Occasionally, people misuse science. For instance, Andrew Wakefield intentionally used falsified data to claim that a vaccine caused autism. If true, this would have been a major breakthrough, so it generated a lot of interest and many more studies. None of them found a correlation. The journal in which he published retracted his paper.
As you can see from these examples, the remedy for bad science is more and better science. Science is self-correcting.
Misconceptions about science
Here are some common misconceptions about science.
“Scientists get paid to support specific theories.” No. Science follows evidence, even if some group (or you) would like a different outcome.
“Science has all the answers.” No. Scientific conclusions are the best explanations we have for things in nature. But science doesn’t explain everything.
“Scientific fraud is common.” No. Hypotheses are checked over and over by people from different organizations and different countries.
“Science has suppressed my theory.” No. Science isn’t a secret society. Real science is public and peer-reviewed. Most “suppressed” theories were never submitted or tested scientifically.
You can do science
You don’t need a degree or a lab coat. If you:
Ask questions about the world
Collect evidence systematically
Test your ideas
And share your results
… you’re doing science. Plus, one way to participate is get involved in some citizen science project. You can find citizen science projects here:
Bottom line: Science means engaging in objective, methodical, repeatable investigations to learn about the natural world.