Unit 7 — Philosophy of Science: How Humanity Learns About Nature

Welcome to Philosophy of Science!

Throughout your education you have studied scientific discoveries from many disciplines.

You have learned mathematics, physics, chemistry, biology, engineering, and computing.

Now it is time to examine a deeper question:

How does scientific knowledge develop?

Philosophy of Science investigates the methods, assumptions, strengths, and limitations of scientific inquiry itself.

Rather than asking only what scientists know, we ask how reliable knowledge is established and continually improved.

Observation

Scientific investigation begins with careful observation.

Students should distinguish between:

• direct observation
• measurement
• interpretation
• inference

Observations provide the foundation upon which scientific explanations are constructed.

Questions

Scientific progress begins with meaningful questions.

Examples include:

• Why do objects fall?
• What causes disease?
• How do species change?
• What is light?
• How did the universe begin?
• How is information stored in DNA?

Questions drive discovery.

Without thoughtful questions, investigation cannot begin.

Hypotheses

A hypothesis is a proposed explanation that can be examined using evidence.

Good hypotheses should be:

• logically consistent
• testable
• evidence-based
• open to revision

Scientific inquiry advances by comparing hypotheses with observations.

Experiments

Experiments allow scientists to test ideas systematically.

Students investigate:

• controlled variables
• independent variables
• dependent variables
• reproducibility
• measurement uncertainty

Well-designed experiments strengthen confidence in scientific conclusions.

Scientific Theories

Scientific theories are comprehensive explanations supported by substantial evidence.

Students should understand that scientific theories differ from ordinary speculation.

Examples include:

• atomic theory
• evolutionary theory
• germ theory
• plate tectonic theory
• relativity
• quantum theory

Theories remain open to refinement when new evidence becomes available.

Scientific Revolutions

Scientific understanding occasionally changes dramatically.

Students investigate historical examples including:

• the Copernican Revolution
• Newtonian mechanics
• Darwinian evolution
• germ theory
• relativity
• quantum mechanics
• plate tectonics

Scientific revolutions demonstrate that knowledge grows through continual investigation rather than permanent certainty.

Evidence and Skepticism

Healthy skepticism is an essential scientific virtue.

Scientists should continually ask:

• What evidence supports this conclusion?
• Could another explanation fit the evidence?
• Have independent investigators confirmed the results?
• What assumptions are being made?
• What remains uncertain?

Skepticism strengthens science when combined with openness to evidence.

The Limits of Science

Science is extraordinarily powerful, but every method has limits.

Scientific investigation is especially effective when studying questions that can be examined through:

• observation
• measurement
• experimentation
• mathematical modeling
• reproducibility

Students should recognize both the strengths and the boundaries of scientific inquiry.

Activity

Choose one major scientific discovery.

Examples include:

• gravity
• evolution
• DNA
• vaccination
• plate tectonics
• electromagnetism

Investigate:

• original observations
• competing explanations
• experiments
• evidence
• scientific acceptance
• continuing research

Explain how scientific understanding developed over time.

Practice

Answer these questions.

Why does science begin with observation?

What makes a hypothesis scientifically useful?

Why are experiments important?

How do scientific theories differ from speculation?

Why do scientific revolutions occur?

Why are skepticism and evidence both essential?

Review

Today you learned:

• scientific knowledge develops through investigation
• questions guide discovery
• hypotheses must be testable
• experiments evaluate explanations
• theories organize large bodies of evidence
• scientific understanding continually evolves
• skepticism strengthens scientific inquiry

Science is one of humanity's greatest intellectual achievements because it continually improves its understanding by following evidence wherever it leads.

Looking Ahead

Next we begin Engineering Design Studio, where students apply mathematics, science, computing, creativity, and systems engineering to design solutions for authentic real-world problems.