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27 Cards in this Set
- Front
- Back
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1.Why did I write that theres one world ocean? What about the pacific and Atlantic oceans, the "seven seas"?
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There are few dependable natural oceanic divisions, only one great mass of water. The pacific and Atlantic Oceans, the Mediterranean and other seas, so named for our convenience, are in reality only temporary features of a single world ocean.
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2.Which is greater: the average depth of the ocean or the average height of the continents about sea level?
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The average land elevation is only 840 meters, but the average ocean depth is 4 1/2 times greater.
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3.Is most of Earths water in the ocean?
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There is much more water trapped within Earth's hot interior than there is in its ocean and atmosphere.
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4.Can the scientific method be applied to speculations about the natural world that are not subject to test or observation?
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The process of science cannot be applied to speculations that are not subject to test or observation. Science requires a logical approach to problem solving and a critical attitude about being shown rather than being told.
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5. What is the nature of "truth" in science? Can anything be proven absolutely true?
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As our observations become more accurate, so do our conclusions about the natural world. Theories may change as our knowledge and powers of observation change, so all scientific understanding is tentative. Because observations (and interpretation of observation) is never perfect, truth can never be absolute.
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6. What if, at the moment you shake the keys, the wires under the hood are jostled by a breeze and fall back into place? what if the car starts when you try it again. ? can you see how superstition might rise?
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Superstitions arise by happenstance. Correlation does not assure causation-that is, just because one event coincidentally occurs with another event, one did not necessarily cause the other.
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7. Can scientific inquiry probe further back in time than the "big bang"?
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Time itself began with the big bang, so the concept of "before" is meaningless in discussing imagined events that preceded the big bang.
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8.What element makes up most of the detectable mass in the universe?
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Hydrogen appears to be the most abundant form of detectable matter in the universe.
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9. Outline the main points in the condensation theory of star and planet formation.
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The condensation theory suggest that stars and planets accumulated from contracting, accreting clouds of galactic gas, dust, and debris. Matterial concentrated near its center became the protosun. Much of the outer material eventually became planets, the smaller bodies that orbit a star and do not shine by their own light.
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10. Trace the life of a typical star
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The life history and death of a star depend on its initial mass. After forming by accretion and spending a long life generating energy from hydrogen fusion, a sunlike star will swell to red giant stage and then slowly pulsate, incinerating its planets and throwing off concentric shells of light gas enriched with these heavy elements.
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11. How are the heaviest elements thought to be formed?
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Stars much more massive than the sun have shower but more interesting lives, which sometimes end in a cataclysmic expansion called a supernova. The explosion lasts only about 30 seconds, but in that short time the nuclear forces holding apart individual atomic nuclei are overcome and atoms heavier than iron are formed. The gold of your rings, the mercury in a thermometer, and the uranium in nuclear power plants were all created during such a brief and stupendous flash.
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12. What is density stratification?
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Density stratification is layering by density- the heaviest material forms deeper layers, and the lighter material forms layers near the surface.
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13. How old is Earth?
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Earth's first surface is thought to have formed about 4.6 billion years ago, so we say Earth is 4.6 billion years old.
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14. How was the moon formed?
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A planetary body somewhat larger than Mars smashed into the young Earth and broke apart. the metallic core fell into Earth's core and joined with it, while the rocky mantle was ejected to form a ring of debris around Earth. The debris began condensing soon after to become our moon.
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15. Is the world ocean a comparatively new feature of Earth, or has it been around for most of Earth's history?
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Most of the ocean was in place about 4 billion years ago. The ocean is an ancient feature of Earth.
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Is Earth's present atmosphere similar to or different from its first atmosphere?
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Free oxygen was missing from Earth's first atmosphere. It was added much later by plantlike organisms.
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Is Earth's present atmosphere similar to or different from its first atmosphere?
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Free oxygen was missing from Earth's first atmosphere. It was added much later by plantlike organisms.
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17. Are the atoms and basic molecules that compose living things different from the molecules that make up nonliving things? where were the atoms in living things formed?
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The atoms and basic molecules that compose life are no different from the molecules in nonliving materials. As youll read in chapter 13, a living thing is defined not by its composition but by its abilitity to manipulate energy. With the exception of hydrogen, all the atoms in living things were formed in stars.
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17. Are the atoms and basic molecules that compose living things different from the molecules that make up nonliving things? where were the atoms in living things formed?
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The atoms and basic molecules that compose life are no different from the molecules in nonliving materials. As youll read in chapter 13, a living thing is defined not by its composition but by its abilitity to manipulate energy. With the exception of hydrogen, all the atoms in living things were formed in stars.
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18. How old is the oldest evidence for life on Earth? on what are those estimates based?
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The oldest fossils yet found are between 3.4 billion and 3.5 billion years old. They are remnants of fairly complex bacteria-like organisms, indicating that life must have originated even earlier, probably only a few hundred million years after a stable ocean formed.
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18. How old is the oldest evidence for life on Earth? on what are those estimates based?
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The oldest fossils yet found are between 3.4 billion and 3.5 billion years old. They are remnants of fairly complex bacteria-like organisms, indicating that life must have originated even earlier, probably only a few hundred million years after a stable ocean formed.
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19. Was Earth's atmosphere rich in oxygen when life originated here?
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No.. Indeed, free oxygen would have broken the complex organic molecules of even simple life-forms. Much of the metabolism of modern organisms is dedicated to protecting those molecules from premature oxidation.
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19. Was Earth's atmosphere rich in oxygen when life originated here?
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No.. Indeed, free oxygen would have broken the complex organic molecules of even simple life-forms. Much of the metabolism of modern organisms is dedicated to protecting those molecules from premature oxidation.
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20. The particles that make up the atoms of your body have existed for nearly all of the age of the universe.
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The ultimate in recycling awaits. Some of the long-lived atoms that have temporarily assembled to comprise your body will be thrown into space as the sun dies, perhaps to be re-accumulated into other structures in the distant reaches of time.
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20. The particles that make up the atoms of your body have existed for nearly all of the age of the universe.
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The ultimate in recycling awaits. Some of the long-lived atoms that have temporarily assembled to comprise your body will be thrown into space as the sun dies, perhaps to be re-accumulated into other structures in the distant reaches of time.
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22. Where would you look for water in our solar system?
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Water is present in our solar system mainly in the form of ice. Comets are comprised of ice and bits of protoplanetary debris (they've been called "dirty snowballs"). There appears to be ice deep in shaded craters near the poles of Earth's moon. Liquid water may (rarely) be present on Mars, but liquid water in significant quantity seems limited to our own clement planet.
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If we encounter life elsewhere, would we expect its chemistry and appearance to resemble life on earth?
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No. We may have recognizing variant forms of life when we see them. Ten-foot tall blue humanoids will almost certainly be exceptions! Haha.
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