What is science?

Science is a shared research activity that uses systematic observation, measurement, reasoning, evidence gathering and critical testing to produce reliable knowledge about nature, society and human beings. It is not merely a collection of memorized facts; it is a dynamic process in which questions are stated clearly, claims are tested against evidence, methods can be scrutinized by others, and conclusions are revised in light of new findings.

The meaning, aims, methods and core concepts of science

1. What is science? Science is the systematic process of producing knowledge in order to explain observable phenomena, understand relationships among them and, under suitable conditions, develop predictions. The strength of scientific knowledge does not rest on an authority saying it is true, but on the quality of the evidence, the transparency of the method and the possibility of independent testing. 2. What are the aims of science? Science aims to describe events, explain causes and mechanisms, produce reliable predictions and organize knowledge so that it can support new questions. Scientific knowledge may become practical applications in medicine, engineering or agriculture, while basic research can lay the foundation for future discoveries even when it does not immediately produce a product. 3. Is the scientific method a single recipe? There is no single method followed in an unchanging order in every investigation. Astronomers may use observational data, geologists field evidence, psychologists experiments and observations, and mathematicians logical proofs. Shared features include clear questions, justified methods, an explicit connection between evidence and conclusions, and openness to criticism and error correction. 4. General stages of research Research often begins with a problem. Earlier publications are reviewed, a testable question is framed and, when appropriate, a hypothesis is proposed. The sample, measurement tools, comparison group and analysis plan are selected, and data are collected according to ethical rules. Results are analyzed and reported with their uncertainties. New evidence may support, modify or reject the explanation. 5. Observation, hypothesis, experiment and evidence An observation is a systematic record of a phenomenon. A hypothesis is a provisional explanation that can be tested with specified evidence. An experiment is a powerful method in which variables are examined under controlled conditions, but not every question can be studied experimentally for ethical or practical reasons. A single observation rarely provides certainty; evidence quality, measurement error and alternative explanations must also be assessed. 6. Variables, controls and causation The independent variable is the factor whose effect is examined, while the dependent variable is the measured outcome. A control group strengthens comparison. Two variables changing together does not by itself show that one causes the other. Establishing causation requires consideration of temporal order, a plausible mechanism, confounding factors and the research design. 7. Measurement, samples and statistics Measurement tools should be valid and reliable. Findings from a small or biased sample cannot automatically be generalized to everyone. Statistics helps assess patterns and uncertainty in data, but does not make a claim true by itself. Effect size, confidence intervals and methodological quality provide broader information than a p-value alone. 8. The difference between a theory and a law A scientific theory is a broad framework that brings together extensive evidence to explain how or why phenomena occur. A scientific law describes a regular relationship under specified conditions, often mathematically. Theories do not turn into laws once enough evidence accumulates: theories explain, laws describe, and they are different kinds of scientific knowledge. 9. Falsifiability and testability It matters whether a scientific claim specifies what finding would weaken its support. A claim that treats every possible result as confirmation cannot be tested effectively. A scientific attitude exposes claims to demanding tests rather than shielding them from criticism, while also considering measurement errors and independent replications.

Scrutiny of scientific knowledge, its branches, limits and place in society

10. Replication and reproducibility Describing a method clearly helps other researchers carry out the same procedures. Similar results under similar conditions increase confidence. For unique historical events, the same explanation can be tested through different data sources and independent measurements. A failure to replicate does not automatically indicate fraud; differences in samples, methods and context are investigated. 11. Peer review and publication Before publication, scientific papers are commonly assessed by experts in the field for their methods, analysis and conclusions. Peer review is an important quality filter, but it does not guarantee freedom from error. Published work may still be criticized, corrected or retracted. Study design, data transparency, conflicts of interest and consistency with other research should all be considered. 12. How does scientific consensus form? Consensus is not an unchangeable truth declared by a vote among researchers. It develops when a large body of evidence from different teams supports one explanation more strongly than its alternatives. A single new study does not immediately overturn the entire body of knowledge. The fact that consensus may change with new evidence does not mean that every view is equally well supported. 13. Error, uncertainty and self-correction No measurement is entirely free from error. Scientists seek to report uncertainty, limitations and possible biases. Mistakes can be corrected and seriously flawed publications may be retracted. Scientific knowledge changing in response to new evidence is not a failure of science but a feature of its capacity for self-correction. Publication bias, conflicts of interest and research incentives also require critical scrutiny. 14. Branches of science Natural sciences include physics, chemistry, biology, astronomy and Earth sciences; social sciences include sociology, psychology, economics, political science and anthropology. Mathematics, logic and statistics are prominent among the formal sciences. Medicine, engineering and agriculture are applied fields. Climate science, neuroscience, bioinformatics and data science are examples of interdisciplinary work. 15. Are science and technology the same? Science focuses on producing reliable explanations and knowledge, while technology focuses on developing tools and systems that meet needs. Technologies such as microscopes and telescopes enable new observations, while scientific knowledge contributes to vaccines, semiconductors and energy technologies. The fact that a technology can be built does not mean that it must be used ethically. 16. Ethics and research integrity In research involving humans or animals, the balance of benefit and harm, informed consent, privacy and independent ethical review are important. Fabrication, falsification and plagiarism are serious violations. Funding sources and conflicts of interest should be disclosed. Ethics is a foundation of trustworthy research that respects human rights. 17. How can pseudoscience be distinguished? Pseudoscientific claims may use scientific language while avoiding testable predictions, selecting only supportive examples or treating contrary evidence as a conspiracy. Personal testimony does not replace controlled research. Sources, methods, samples, independent replication and the assessments of expert organizations should be examined together. Expressions such as “miracle,” “guaranteed cure” or “hidden truth” require careful verification. 18. The limits of science and scientific literacy Science offers powerful answers to questions that can be investigated through observation and evidence; it cannot by itself decide normative questions such as what is morally right or the meaning of life. When reading research news, go beyond the headline: find the original study or a reliable institutional summary, examine the sample and methods, and do not treat one study as final proof. For important health, environmental and safety decisions, systematic reviews and current assessments from authoritative scientific bodies are stronger starting points. Frequently asked questions “Does science know everything with certainty?” No; it seeks to measure uncertainty and rank explanations by the strength of evidence. “Why do scientists disagree?” Different data, methods and interpretations can lead to debate, which is part of the critical process. “Is a theory merely a guess?” No; a scientific theory is an explanatory framework supported by extensive evidence. “If science changes, is it unreliable?” Its ability to improve in response to new evidence is one of its reliability mechanisms. Source basis: UNESCO — Recommendation on Open Science; National Academies — On Being a Scientist; University of California Museum of Paleontology — Understanding Science. Sources checked on 10 October 2026.