Chapter 1 Notes – About Science

What Science Is

  • Science is a body of knowledge.

  • Science is an ongoing human activity.

  • Its beginnings precede recorded history.

  • It is a quest to understand the laws of nature.

Scientific Measurements

  • Measurements are a hallmark of good science.

  • Lord Kelvin: when you can measure something and express it in numbers, you know something about it; when you cannot measure, knowledge is meager and unsatisfactory.

  • Measurements relate to how much you know about something.

  • Examples: pinhole images of the Sun lead to a calculation of the Sun's diameter; crescent shapes occur in partial solar eclipses.

Early Measurements

  • Eratosthenes — Diameter of Earth (235 B.C.)

    • Distance between Alexandria and Syene: 500\ \text{stadia}\ (\approx 8{,}000\ \text{km})

    • Circumference: C \approx 2.5\times 10^4\ \text{stadia}

  • Aristarchus — Distance and Size of the Moon (240 B.C.)

Mathematics—The Language of Science

  • Mathematics is the natural language of science.

  • Scientific ideas are unambiguous when expressed mathematically.

  • Equations express relationships between concepts and serve as guides to thinking.

Scientific Methods

  • There is no single scientific method.

  • General procedures involve:

    • recognizing a question or puzzle,

    • formulating a hypothesis,

    • predicting consequences,

    • performing experiments or calculations to test predictions,

    • formulating the simplest general rule that organizes these steps.

The Scientific Attitude

  • The scientific attitude emphasizes:

    • inquiry,

    • experimentation,

    • willingness to admit error.

  • Scientists are experts at changing their minds.

  • They must accept experimental findings, test erroneous beliefs, and understand objections.

Facts, Hypotheses, Law, Theory

  • Fact: close agreement by competent observers who make a series of observations.

  • Hypothesis: an educated guess, presumed factual until supported by experiment.

  • Law (Principle): a hypothesis that has been repeatedly tested and not contradicted.

  • Theory: a synthesis of a large body of information that encompasses well-tested and verified hypotheses about aspects of the natural world.

Science, Art, and Religion

  • Science deals with the natural order: discovery and recording of natural phenomena.

  • Art involves interpretation and expression of human experience.

  • Religion involves faith and worship of a supreme being.

Similarities and Connections

  • Art and science both involve knowledge of what is possible and influence our worldview.

  • Religion and science both address unanswered questions.

Science and Technology

  • Science: gathering and organizing knowledge.

  • Technology: use of scientific knowledge for practical purposes and as tools for further exploration.

Physics—The Basic Science

  • Physical sciences: geology, astronomy, chemistry, and physics.

  • Life sciences: biology, zoology, and botany.

  • Physics underlies all the sciences.

Notes

  • Copyright statements and boilerplate are not part of the conceptual content.