Hypothesis vs Theory in Science
Hypothesis
A specific, testable proposed explanation for an observation — the starting point of an investigation. It must make predictions that an experiment could prove wrong.
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Example: 'If the string is longer, the pendulum's period will be longer' — a hypothesis you can test tomorrow with string and a stopwatch.
Scientific Theory
A broad, well-substantiated framework that explains a wide range of phenomena and has survived repeated testing — germ theory, plate tectonics, general relativity. In science, 'theory' is the highest honor, not a guess.
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Example: The theory of general relativity predicted gravitational lensing and time dilation — both later confirmed by observation to stunning precision.
Key differences
| Aspect | Hypothesis | Scientific Theory |
|---|---|---|
| Scope | Narrow — one question, one experiment | Broad — unifies many phenomena |
| Evidence level | Proposed, awaiting testing | Extensively tested and confirmed |
| Role | Starting point of inquiry | Mature explanatory framework |
| If disproven | Discarded or revised — normal science | Would require overturning mountains of evidence |
| Everyday meaning trap | 'My hypothesis' ≈ educated guess (fine) | 'Just a theory' misuses the word — theories are the opposite of guesses |
Saying 'evolution is just a theory' treats the scientific meaning like the everyday one. In science, a theory is what a hypothesis grows into after surviving every test thrown at it — nothing outranks it.