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History and philosophy

 

History

article: History of science

Science in a broad sense existed before the modern era, and in many historical civilizations, but modern science is so distinct in its approach and successful in its results that it now defines what science is in the strictest sense of the term. Much earlier than the modern era, another important turning point was the development of the classical natural philosophy in the ancient Greek-speaking world.
 

Pre-philosophical

Science in its original sense is a word for a type of knowledge (Latin scientia, Ancient Greek episteme), rather than a specialized word for the pursuit of such knowledge. In particular it is one of the types of knowledge which people can communicate to each other and share. For example, knowledge about the working of natural things was gathered long before recorded history and led to the development of complex abstract thinking, as shown by the construction of complex calendars, techniques for making poisonous plants edible, and buildings such as the pyramids. However no consistent distinction was made between knowledge of such things which are true in every community, and other types of communal knowledge such as mythologies and legal systems.
 

Earth science

Earth science (also known as geosciences, the geosciences or the Earth sciences) is an all-embracing term for the sciences related to the planet Earth. It is arguably a special case in planetary science, the Earth being the only known life-bearing planet. There are both reductionism and holistic approaches to Earth sciences. The formal discipline of Earth sciences may include the study of the atmosphere, hydrosphere, oceans and biosphere, as well as the solid earth. Typically Earth scientists will use tools from physics, chemistry, biology, chronology and mathematics to build a quantitative understanding of how the Earth system works, and how it evolved to its current state.

 

A volcano eruption is the release of stored energy from below the surface of Earth, originating from radioactive decay and gravitational sorting in the Earth's core and mantle, and residual energy gained during the Earth's formation.

 

Lava flows from the Kilauea volcano into the ocean on the Island of Hawaii

Earth's electromagnetic field

An electromagnet is a magnet that is created by a current that flows around a soft iron core. Earth has a solid iron inner core surrounded by semi-liquid materials of the outer core that move in continuous currents around the inner core; therefore, the Earth is an electromagnet. This is referred to as the dynamo theory of Earth's magnetism
 

Atmosphere

The troposphere, stratosphere, mesosphere, thermosphere, and exosphere are the five layers which make up Earth's atmosphere. In all, the atmosphere is made up of about 78.0% nitrogen, 20.9% oxygen, and 0.92% argon. 75% of the gases in the atmosphere are located within the troposphere, the bottom-most layer. The remaining one percent of the atmosphere (all but the nitrogen, oxygen, and argon) contains small amounts of other gases including CO2 and water vapors. Water vapors and CO2 allow the Earth's atmosphere to catch and hold the Sun's energy through a phenomenon called the greenhouse effect. This allows Earth's surface to be warm enough to have liquid water and support life.

The magnetic field created by the internal motions of the core produces the magnetosphere which protects the Earth's atmosphere from the solar wind. As the earth is 4.5 billion years old, it would have lost its atmosphere by now if there were no protective magnetosphere.

In addition to storing heat, the atmosphere also protects living organisms by shielding the Earth's surface from cosmic rays. Note that the level of protection is high enough to prevent cosmic rays from destroying all life on Earth, yet low enough to aid the mutations that have an important role in pushing forward diversity in the biosphere.

 

  The magnetosphere shields the surface of Earth from the charged particles of the solar wind. It is compressed on the day (Sun) side due to the force of the arriving particles, and extended on the night side.  
     
 

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