Introduction to Metric System and Science

Feb 18, 2025

Lecture Notes: Introduction to Metric System and Scientific Method

Introduction

  • Welcome to the introductory chapter of the course.
  • Topics covered in this lecture:
    • Metric System
    • Scientific Method

Metric System

Overview

  • Also known as SI units.
  • Used globally by scientists and in trade (Trade Act of 1988).
  • Only the US, Liberia, and Myanmar do not use the metric system extensively.

Advantages

  • Easy math: all units are multiples of 10.
  • Common prefixes: kilo, centi, milli, micro, nano, pico.

Examples and Conversions

  • 1 kilometer = 1,000 meters = 100,000 centimeters.
  • 1 meter = 100 centimeters = 1,000 millimeters.
  • Important to understand scientific notation (e.g., 10^3 = 1,000).

Temperature Scale

  • Celsius scale: 0°C is freezing, 100°C is boiling.
  • Conversion: °C = (°F - 32) / 1.8.

Length and Distance

  • SI unit of length: meter.
  • 1 meter originally defined by the distance from the North Pole to the equator.
  • Modern definition: the distance light travels in a vacuum in 1/299,792,458 seconds.

Practical Examples

  • Average ocean depth ~3.8 kilometers or ~4,000 meters.
  • Conversions: 1 meter ~ 1.1 yards, 1 kilometer ~ 0.7 miles.

Scientific Method

Purpose

  • Discover underlying patterns and make predictions in the natural world.
  • Assumes consistent operation of physical laws across time and space.

Process

  1. Observation: Collection of scientific facts.
  2. Hypothesis: Testable statement about the natural world.
  3. Testing: Observations, experiments, and models to test the hypothesis.
  4. Theory: Well-substantiated explanation after extensive testing.

Characteristics

  • Science evolves with new observations.
  • Theories are based on testable and observable data.
  • Example: Evolution, heliocentric theory.

Example of the Scientific Method in Action

  • Observation: Pond water is green.
  • Hypothesis: Excess algae (e.g., chlorella) cause greenness.
  • Testing: Measure and compare algae in different ponds.
  • Results: Accept/reject hypothesis. Generate new hypotheses if necessary.

Conclusion

  • Next lecture will cover latitude and longitude as part of the introductory topics.

Note

  • Familiarity with metric units and scientific methods is essential as they will be frequently referenced in the course.
  • Suggested tools for unit conversion: apps like UnitPlus.
  • Importance of curiosity in scientific inquiry.