Social Sciences: Class 6 — Chapter 1: Locating Places on the Earth

• Theme A – India and the World: Land and the People: Explores geographical features, maps, and how natural settings shape civilisations.
• Theme B – Tapestry of the Past: Explores history to understand the present, our identities, and learn from past mistakes.
• Theme C – Our Cultural Heritage and Knowledge Traditions: Explores India's rich cultural foundations and guiding principles.
• Theme D – Governance and Democracy: Explores political systems, citizenship, rights, and duties (dharma).
• Theme E – Economic Life Around Us: Explores economic activities, resources, and how economies function.

A map is a representation or drawing of an area on a flat surface, viewed from the top. An atlas is a collection of maps.

Types of Maps:

• Physical maps: Show natural features like mountains, rivers, and oceans.
• Political maps: Show boundaries of countries, states, cities, and capitals.
• Thematic maps: Focus on specific information (e.g., rainfall, vegetation, industries).

Three Key Components of Maps:

• Scale (Distance): The ratio between the actual distance on the ground and the distance shown on the map (e.g., $1\text{ cm} = 500\text{ m}$).
• Direction: Includes cardinal directions (North, East, South, West) and intermediate directions (Northeast, Southeast, Southwest, Northwest).
• Symbols: Drawings, letters, or colors used to represent real-world features in limited space.

The Earth is nearly a sphere (slightly flattened at the poles). Representing a sphere accurately on a flat sheet of paper is impossible without distortion. A globe is a spherical model of the Earth that represents its geography accurately.

A system of coordinates uses two values to precisely determine any location on Earth.

Latitudes:

• The Equator is the imaginary line halfway between the North Pole and South Pole, representing $0^\circ$ latitude.
• Parallels of latitude are imaginary circles running parallel to the Equator, getting smaller towards the poles ($90^\circ\text{N}$ and $90^\circ\text{S}$).
• Latitude and Climate: Near Equator is hot (torrid), mid-latitudes are moderate (temperate), and near poles are cold (frigid).

Longitudes:

• Meridians of longitude are imaginary half-circles running from the North Pole to the South Pole.
• The Prime Meridian (Greenwich Meridian) is the reference line ($0^\circ$ longitude) passing through Greenwich, London.
• Longitudes increase from $0^\circ$ to $180^\circ$ East (E) or West (W).
• Historical Note: Long before Europe, India used its own prime meridian called madhya rekhā passing through Ujjayinī (modern Ujjain), associated with astronomer Varāhamihira.

The Grid:

The intersection of parallels of latitude and meridians of longitude forms a grid, allowing precise location tracking (e.g., Delhi lies at approximately $29^\circ\text{N}, 77^\circ\text{E}$).

The Earth rotates from west to east, completing a full turn of $360^\circ$ in 24 hours ($15^\circ$ per hour or $1^\circ$ every 4 minutes).

• Local Time: Calculated based on the sun's position at a specific meridian. Moving $15^\circ$ eastward adds 1 hour; moving $15^\circ$ westward subtracts 1 hour.
• Standard Time: A single meridian chosen to represent the entire country's time. Indian Standard Time (IST) is based on the $82.5^\circ\text{E}$ meridian, which is $5.5$ hours ahead of Greenwich Mean Time (GMT).
• Time Zones: The world is divided into time zones that generally follow international borders. Large countries have multiple time zones (e.g., USA has 6, Russia has 11).
• International Date Line: Located approximately at $180^\circ$ longitude. Crossing it traveling eastward subtracts a day; traveling westward adds a day.