Overview
This lecture explains how science defines and uses terms like fact, hypothesis, theory, and law, and emphasizes the importance of understanding these to trust scientific knowledge.
Scientific Terms: Everyday vs. Scientific Use
- In science, words like "fact," "theory," "hypothesis," and "law" have specific meanings different from everyday language.
- Scientific understanding relies on a shared, precise vocabulary.
The Scientific Method
- Facts are observations about the world (e.g., it's bright outside).
- A hypothesis is a tentative explanation for observations that can be tested.
- Hypotheses are tested through experiments and may be confirmed or refuted.
- Eliminating incorrect hypotheses refines our understanding but does not provide ultimate truth.
- A theory is a well-substantiated explanation formed from multiple tested hypotheses and evidence.
- Theories enable scientists to make predictions about future events or phenomena.
Examples of Scientific Terms in Use
- "Germ Theory of Disease" explains why people get sick through many tested hypotheses.
- "Evolution" is a fact (it happens), while "evolution by natural selection" is a theory explaining how it happens.
- Theories are not guesses; they have passed rigorous testing and are predictive frameworks.
Facts, Laws, and Theories: Gravity Example
- Facts: Dropping an object makes it fall.
- Law: Newton’s Law of Universal Gravitation mathematically describes how objects attract based on mass and distance.
- Theory: Einstein’s General Relativity explains why gravitational effects occur.
- Laws describe how, but not why; theories explain underlying reasons.
Science as a Dynamic Process
- Scientific theories can be updated when new evidence arises (e.g., quantum mechanics challenging General Relativity).
- Science is incomplete and always evolving; this is a strength, not a weakness.
- Scientific knowledge is robust but adaptable as new discoveries are made.
Key Terms & Definitions
- Fact — an observation about the world.
- Hypothesis — a testable explanation for an observation.
- Theory — a comprehensive explanation based on evidence and multiple tested hypotheses.
- Law — a detailed, often mathematical, description of how phenomena occur.
Action Items / Next Steps
- Review definitions of fact, hypothesis, theory, and law.
- Apply scientific vocabulary accurately in class discussions and assignments.