Timeline and Sources of History | Chapter 4 One Shot | Class 6 Social Science | New NCERT

Summary

What the Chapter Is About

The lesson introduces historical timelines and sources of history. It focuses on three questions:

• How is historical time measured?
• How do different sources help us learn about the past?
• How did early humans live, and how did settled communities develop?

A museum preserves objects from the past—such as coins, ornaments, statues and utensils—that people can study to learn about history.

The Long History of Life on Earth

Earth’s history stretches back far longer than human history. The lesson traces a broad progression from early life to increasingly complex organisms: cells and microorganisms; sponges, corals and fish; insects, amphibians, reptiles, birds and mammals; flowering plants; and primates.

Key dates highlighted in the lesson include:

• Earth formed about 4.54 billion years ago.
• Atmospheric oxygen is marked at about 2.33 billion years ago.
• Primates appeared millions of years ago.
• Humans—Homo sapiens—appeared about 300,000 years ago.
• Writing is placed at roughly 6,500 years ago.

Humans arrived very late in comparison with Earth’s age, so they occupy only a tiny part of Earth’s long history.

People Who Study the Past

Different specialists investigate different aspects of the past:

• Geologists study Earth’s physical features, including rocks, soil, hills, rivers and oceans.
• Paleontologists study fossils: the preserved remains or traces of ancient plants and animals.
• Anthropologists study human societies and cultures.
• Archaeologists excavate and study material remains left behind by people, plants and animals, such as tools, pottery, bones, beads and building remains.

The lesson offers a memory aid: rivers, mountains and hills are associated with geologists; fossils with paleontologists; culture and society with anthropologists; and digging up objects with archaeologists.

Eras, Calendars and Historical Time

An era is a long, distinct period associated with particular events, developments or characteristics. Examples include the Mughal, Mauryan and Victorian eras.

Calendars organize dates and mark events. The Gregorian calendar is the most widely used calendar today. The lesson also mentions the Hindu, Muslim, Jewish and Chinese calendars. The traditional Indian Panchang uses its own month names and astronomical information.

The Gregorian calendar has 12 months and normally 365 days. A leap year generally occurs every four years, with an exception for century years:

• A year that is not a century year is a leap year if it is divisible by 4.
• A century year is a leap year only if it is divisible by 400.
• For example, 2024 is divisible by 4. A century year such as 2000 must meet the stricter divisibility-by-400 rule.

CE, BCE and the Historical Timeline

The lesson explains two common systems for labelling years:

• CE means Common Era and is used in place of AD.
• BCE means Before Common Era and is used in place of BC.

CE years increase as time moves forward, while BCE years count down toward the transition between the two eras. There is no year zero: 1 BCE is followed by 1 CE.

Useful calculation rules:

• For dates on the same side of the BCE/CE divide, subtract the earlier date from the later one.
• To find the number of years between a BCE date and a CE date, add the two year numbers and subtract 1: BCE date + CE date − 1.
• To estimate a date a given number of years before a present CE year, account for the missing year zero. The lesson works through an example using 2025 CE and 12,000 years ago.

A timeline places events in sequence, making it easier to see what happened earlier or later. Long timelines often use gaps or dotted sections to remain manageable.

Centuries and Millennia

A century is a period of 100 years. In CE:

• The 1st century runs from 1 to 100 CE.
• The 20th century runs from 1901 to 2000 CE.
• The 21st century runs from 2001 to 2100 CE.

BCE centuries are counted in reverse chronological direction. For example, the 3rd century BCE covers 300–201 BCE.

A millennium is a period of 1,000 years. The lesson says that we are in the third millennium CE, which began in 2001 CE.

Sources of History

Historians use many kinds of evidence. A source is like one piece of a puzzle: combining sources can help build a fuller picture of past events.

Oral Sources

Oral sources are passed verbally from one generation to another.

• Genealogical information concerns a family’s origins and history.
• Folklore includes a community’s traditional stories, beliefs and customs.

The lesson also suggests investigating family history by asking relatives and checking documents, photographs, diaries and other records.

Literary Sources

Written sources include:

• Indian texts such as the Vedas, epics, historical writing and story collections such as the Panchatantra.
• Poems and plays, which can reveal aspects of the time in which they were written.
• Scientific and technological texts.
• Foreign accounts, including travelogues written by visitors to India.
• Historical chronicles, which record events in detail and in chronological order.

Artistic Sources

Paintings, sculptures and carvings can provide evidence about people, rulers, cultural practices and events. Carved panels are also discussed as parts of larger buildings.

Inscriptions and Written Objects

The lesson discusses manuscripts, copper plates and coins. Manuscripts are handwritten works on materials such as paper, bark, cloth, metal or palm leaves. The lesson emphasizes that historically significant manuscripts have scientific or historical value.

Archaeological Sources

Objects and remains recovered through excavation can include:

• Monuments and mounds
• Tools and weapons
• Figures, ornaments, pottery and toys
• Remains of houses or other habitats
• Human, animal and plant remains
• Burials

A monument is a structure built to commemorate a person or event. A mound can be a raised accumulation of earth, stones and debris, sometimes covering an older settlement.

Recent and Scientific Evidence

Newspapers and electronic media can help researchers study recent history. Scientific methods can also provide new information—for example, by analyzing excavated materials, ancient climates or the genetics of ancient people.

Historians and Other Contributors

Historians use multiple sources to investigate subjects such as rulers, monuments, wars and trade. Archaeologists, epigraphists (who study inscriptions), anthropologists, and specialists in literature and language also contribute. Scientific analysis can help interpret evidence that would otherwise be difficult to understand.

Early Humans and the Beginnings of Settled Life

The lesson dates the appearance of Homo sapiens to about 300,000 years ago and describes early human life as difficult and shaped by the natural environment.

Early humans:

• Lived in groups and helped one another.
• Moved in search of shelter and food.
• Hunted animals and gathered edible plants and fruits, which is why they are called hunters and gatherers.
• Used caves or rock shelters and fire.
• Used animal skins for covering themselves.
• Made tools and weapons from materials such as stone.
• Created rock paintings and simple ornaments from stones, shells and animal teeth.

The lesson also describes an Ice Age that ended about 12,000 years ago. As conditions became more favourable, people in some places began cultivating cereals and grains and domesticating animals such as cattle and goats. Greater food availability helped communities grow and settle, often near rivers, which provided water and fertile soil.

Over time, communities developed leaders and more complex social structures. Small settlements, or hamlets, grew into villages and towns. People exchanged goods, and technologies such as pottery and the use of metals developed. Copper is presented as an earlier metal than iron. These changes helped prepare the way for the emergence of civilizations.

Speakers and Sources Featured

• Speaker: Yogita Dhami, the lesson’s mentor and presenter from Concept Corridor. No other speaking guest is identifiable in the subtitles.
• Historical and educational examples mentioned: The National Museum in New Delhi; the Gregorian calendar and Panchang; the Vedas and Panchatantra; travel accounts associated with Vasco da Gama, Ibn Battuta and Xuanzang; and a coin identified in the lesson as associated with Samudragupta.
• Types of historical sources discussed: Oral accounts and folklore, literary texts and travelogues, paintings and sculptures, manuscripts, copper plates, coins, monuments, mounds, excavated objects and remains, newspapers, electronic media and scientific studies.