Understanding Map Projections

Introduction

• Converting a globe into a flat map involves cutting and distorting the surface.
• Represents the dilemma of map makers: spherical surfaces cannot be represented without distortion.

Historical Context

• Since the 1500s, mathematicians have worked on algorithms to convert the globe into flat representations.
• The process used for this is known as projection.

Types of Projections

• Cylindrical Projection:

  • The globe is covered with a theoretical cylinder.
  • Points on the sphere are projected onto the cylinder's surface.
  • When unrolled, it creates a flat map.

• Trade-offs of Projections:

  • Every projection affects shape, distance, direction, and land area.
  • Can be misleading or helpful based on usage.

Mercator Projection

• Characteristics:
  • Preserves country shapes (e.g., Brazil retains its shape).
  • Designed for navigation; preserves direction crucial for ocean navigation.
• Drawbacks:
  • Distorts size; Greenland appears similar in size to Africa, but Africa is actually 14 times larger.
  • Prolongs imperialist attitudes by misrepresenting southern hemisphere countries.

Gall-Peters Projection

• Equal-Area Projection:
  • Accurate size representation (e.g., Greenland vs. Africa).
  • Shapes are stretched, leading to distortion.

Impact of Technology on Mapping

• Introduction of GPS:
  • Satellites changed navigation needs, reducing reliance on paper maps.
  • Shifted focus from navigational accuracy to aesthetics and presentation in mapping.
• Current Use of Mercator:
  • Still prevalent in web mapping tools (e.g., Google Maps) for close-up accuracy.

Modern Cartography

• Cartographers often prefer non-rectangular projections to balance size and shape accuracy.
• Winkel Tripel Projection:
  • Adopted by National Geographic in 1998 for its balanced representation.

Conclusion

• No single "right" projection exists; each offers a different perspective of the planet.
• The globe presents the most accurate representation of Earth.
• The trade-offs of flat maps remain a challenge.