The Nature of Science

What Do You Think? True of False All scientists do experiments to get data. A theory is unproven and lacks sufficient evidence to become a law. Science and its methods can answer all questions. Perception is always reality.

Myth: All scientists do experiments to get data. Only Experiments?? Experiments are important in science but experiments are not the only way to get data. Observational Data Diane Fossey – Gorillas Astronomy Meteorology

Only One Way of Doing Science? There are multiple methods for doing science. Rather than rely on a flow chart and a strict set of steps, follow what makes sense for the type of research you are doing.

Myth A theory is unproven and lacks sufficient evidence to become a law. Definitions: Idea – Something one thinks, knows or imagines. Does not need an explanation Does not require evidence Examples: His legs are too weak. Humans crave power.

Scientific Hypothesis Hypothesis – a proposed explanation for an observable phenomenon. Must be testable through experiments or observations. Examples: If you give a plant more fertilizer, it will grow more. A new drug is more effective than an old drug.

Fact – separate, small bits of information based on observations. Scientific Fact Fact – separate, small bits of information based on observations. Examples: Humans have 46 chromosomes Prokaryote cells have a nucleus

Scientific Law Law- Describes how nature acts under certain conditions, without describing why. Supported with scientific evidence. Examples: Law of Segregation- Pairs of chromosomes separate during meiosis. Law of Gravity – What goes up, must come down. Law of Evolution- Living things change over time.

Scientific Theory THEORIES DO NOT BECOME LAWS. They are different things. Theory- Explains how nature works. General set of principles that has explanatory power. Supported with scientific evidence. Examples: Theory of Plate Tectonics – How the continents shifted over time. Theory of Natural Selection- How genetics change due to the environment.

Myth Science and its methods can answer all questions. Science is limited to questions related to the physical world. Scientific explanations require evidence. Scientific explanations have to fit all of the evidence. Scientific knowledge is tentative, subject to revision in light of new evidence. It can be disproven. Scientific knowledge is cumulative. It builds on prior knowledge.

Consider the following statements: The sun moves around the earth. Myth: Perception is reality. Consider the following statements: The sun moves around the earth. The earth is flat and not moving. Species are fixed and unchanging. Eyes are perfect little cameras.

How many legs does this elephant have?

Are there black dots?

Are the images moving?

How many faces do you see?

All scientists do experiments to get data. Now – What do you think? All scientists do experiments to get data. A theory is unproven and lacks sufficient evidence to become a law. Science and its methods can answer all questions. Perception is always reality.