Maximum Age of the Earth

The maximum age of the Earth is about 4.5 billion years.

Key Points

1. Dating Techniques

• Description: Scientists determine the age using methods like radiometric dating of rocks and minerals.
• Illustration: Analyzing uranium in zircon crystals helps estimate how old they are.

2. Oldest Rocks

• Description: The oldest known rocks on Earth, found in Canada, are around 4.0 billion years old.
• Illustration: These ancient rocks provide clues about the early Earth.

3. Cosmic Context

• Description: Earth formed from the same material as the Sun and other planets about 4.5 billion years ago.
• Illustration: Understanding Earth’s age helps scientists study the history of the solar system.

This immense age shows how long our planet has been evolving.

Environmental Ethics

Environmental ethics is a branch of philosophy that studies the moral relationship between humans and the natural world.

Key Principles

1. Respect for Nature

• Description: It emphasizes that all living beings and ecosystems have value and should be treated with respect.
• Illustration: Protecting forests not only benefits humans but also preserves habitats for countless species.

2. Human Responsibility

• Description: Humans have a duty to care for the environment, ensuring resources are used sustainably.
• Illustration: Reducing plastic waste helps keep oceans clean for future generations.

3. Balance Between Development and Conservation

• Description: Environmental ethics promotes sustainable development, balancing human needs with ecological protection.
• Illustration: Solar energy is encouraged as a cleaner alternative to fossil fuels.

Environmental ethics guides us to act in ways that protect and respect the Earth for all life forms.

Start of Remote Sensing in India

India began its remote sensing efforts in the early 1980s with the launch of its first experimental remote sensing satellite.

Key Milestones

1. First Satellite

• Launch: India’s first remote sensing satellite, IRS-1A, was launched in 1988.
• Illustration: This satellite marked India’s entry into Earth observation and resource management.

2. Purpose

• Description: The program aimed to monitor agriculture, forestry, water resources, and disaster management.
• Illustration: Using satellite images, India could better manage natural resources and support development.

Today, India’s remote sensing program is one of the most advanced, providing valuable data for national and global use.

World Health Organization (WHO)

The World Health Organization (WHO) is a special agency of the United Nations focused on global health. Here are its main features:

1. Purpose

• Description: WHO aims to promote health, keep the world safe, and serve vulnerable populations.

2. Global Coordination

• Description: It coordinates responses to health emergencies, like disease outbreaks.
• Illustration: WHO played a key role in the COVID-19 response.

3. Guidelines and Research

• Description: WHO sets health standards and provides guidelines for improving health worldwide.
• Illustration: It issues recommendations on vaccination and disease prevention.

Main Functions of Root Hairs in Plants

Root hairs are tiny, hair-like structures that play an important role in a plant’s growth and survival. Here are their main functions:

1. Water Absorption

• Description: Root hairs increase the surface area for absorbing water from the soil.
• Illustration: Think of them as tiny straws that soak up water.

2. Nutrient Uptake

• Description: They help absorb essential nutrients like nitrogen and potassium.
• Illustration: Like tiny filters, they grab nutrients needed for growth.

3. Anchoring the Plant

• Description: Root hairs help stabilize the plant in the soil.
• Illustration: They act like small anchors, holding the plant in place.