Summary Of Key Ideas Earth Science

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Technological advances and environmental incidents have encouraged scientists to look at Earth as a system. A system is a kind of model that allows scientists to study a process or phenomenon with time as a variable. Because Earth exchanges little matter with its surroundings, it is an essentially closed system.

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The Earth system includes four spheres: the atmosphere, geosphere, hydrosphere, and biosphere. The atmosphere is the gaseous envelope surrounding Earth. The geosphere consists of all the physical features on Earth except water. Earth's water makes up the hydrosphere. Living things, including plants, animals, and peple, make up the biosphere. The spheres interact and change constantly.

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All water on Earth is continually moving through the water cycle, which includes evaporation, transpiration (evapotranspiration), and precipitation. A biogeochemical cycle involves the movement of an element, such as carbon, through the four spheres of the Earth system. The Earth system has three energy sources: solar energy, geothermal energy, and tidal energy.

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Scientists come from many different backgrounds, but in their work they use common tools, techniques, and habits of mind. The qualities of scientific thinking include asking questions, seeking evidence, forming hypotheses, testing hypotheses, being skeptical, and working cooperatively. Technology plasy an important role in applying scientific discoveries to everyday life.

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Doing science is a complex process that does not proceed neatly from one revelation to the next. When scientists investigate questions, they state the question, gather evidence, form a hypothesis, and test the hypothesis. Scientists publish their results in scientific journals, which provides the opportunity for their peers to review their work. Testing ideas is vital to science. When a hypothesis has been thoroughly tested, it may be considered a theory, an explanation for observable for which no exceptions have been noted. Scientific laws are generalizations about the natural world and how it behaves.

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Scientists use a variety of tools, both simple and complex, as they study the earth, ocean, sky, and stars.

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A flat map of a curved surface is distorted. Different map projections are used to minimize distortion of shape, distance, or direction. On a map horizontal lines show latitude, positions north and south of the equator. Vertical lines show longitude, positions east and west of the prime meridian. Map scales compare the size of the map's features with Earth's surface.

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The use of remote-sensing methods allows mapmakers to produce accurate maps of many places on Earth. With the help of computers, cartographers use remote-sensing data to make detailed maps. Images produced useing data from satellites are used in many areas of science and research.

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Topographic maps indicate elevation and average slope by using contour lines. Colors are used to indicate various features on topographic maps, including water and human-made structures.

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Earth formed about 4.6 billion years ago from a whirling cloud of dust and gas. It deceloped layers as it cooled and dense material sank to its center. Meteorite impacts, the weight of overlying material, and the decay of radioactive isotopes caused Earth to heat up soon after its formation. Since then, Earth has been losing heat. Earth has a magnetic field.

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Earth makes one complete turn on its axis about every 24 hours. Its axis of rotation is tilted with respect to Earth's orbital plane. Effects of this rotation include the Coriolis effect, Foulcault pendulum behavior, day and night, and sunrise and sunset. Earth is divided into 24 worldwide standard time zones that begin at the prime meridian.

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Earth revolves around the sun in an elliptical orbit with the sun as one focus. Earth's revolution along with its tilt cause season changes. The summer and winter solsttices are the longest and shortest days of the year, respectively. On the vernal and autumnal equinoxes, day and night are of equal lengths.