Stars have an average lifetime of 5 billion years, so we obviously cannot study one from birth to death.
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There is a universe in a grain of sand. Three of the four known forces of nature combine to hold together the nuclei of atoms and their electron clouds. Contained within the atomic and crystal structure of the sand and all atoms are all of the forces that exist in the universe.
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Some say they have seen it, but most never have. Others say it does not exist, and yet others think they have seen it but really have not.
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Clouds have a dual personality. On one hand, they form beautiful piles of fluffy white cumulus, flat sheets of stratus and feathers of icy cirrus, all of which entertain with spectacular yellow, orange and red sunrises and sunsets.
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Carbon is undoubtedly the most important chemical element on Earth. It is the element of life, the source of most of the world’s energy, the basis of plastics and the major industrial pollutant in the atmosphere.
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Over the past 30 years, research has clearly identified the adverse health effects of trans fatty acids, most notably on coronary heart disease.
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The chance that any one of us will consume some fermented food or beverage today is 100%. That is to say, it is certain. Bread, cheese, yogurt, beer and wine, cured salami, cocoa and pickled foods such as sauerkraut and kimchi are some examples of fermented products.
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On June 8 people around the globe celebrated World Oceans Day. National Geographic magazine had a special reason for celebration: The frigid waters that flow around Antarctica have long been known as the Southern Ocean because its properties are relatively uniform throughout.
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When we hear the word “isotope,” most of us would think of radioactivity. Radioactive analysis is the most commonly known form of isotopic analysis, but it is only a part.
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Using nothing but a compass as a navigational tool, ancient mariners from China to Sumer navigated the world’s oceans. Even in the modern age of GPS, the magnetic compass is an unfaltering navigational tool for seagoing vessels, airplanes and hikers on the ground.
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Rock salt is a mineral, halite. It occurs in massive underground deposits on all continents. In its pure form it is sodium chloride, a crystalline substance composed of equal numbers of sodium and chlorine atoms.
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Thermonuclear reactions deep in the sun’s interior consistently generate the same amount of energy as 2.5 billion 500-megawatt generators, the largest on Earth. In one short second the sun produces enough energy to power New York City for 100 years.
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The association of eggs and rabbits with Easter is not immediately apparent. Easter is a Christian holiday, and it is a celebration of fertility and rebirth, the modern continuation of ageless rites of spring that we have borrowed and adapted from ancient pagan rituals.
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The sun is the source of all life and almost all energy on Earth, and we live within its extended atmosphere, protected only somewhat against its variable and harmful output of streams of high-energy particles and radiation by a weak magnetic field and our own thin atmosphere.
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The hydroxyl radical is the dominant oxidizing chemical in Earth’s atmosphere. It is also the most common and most active free radical present in human and other animal tissue, yet it is contained in chemically pure water.
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The polar vortex is a permanent low-pressure system that surrounds the geographical north and south poles. “Vortex” refers to the circulation around the poles. The term also describes smaller vortices that occur within lobes of the primary vortex.
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The connection between electricity and magnetism was discovered by accident.
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Luigi Galvani discovered bioelectricity in the late 1770s when he began to experiment with the muscular contraction of frog legs by electrical stimulation.
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