Từ vựng về Cosmic Evolution


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adaptation -- the response to a changing environment of an organism's structure or function in a way that improves its chance for survival and reproduction.

alpha process -- the capture of helium nuclei, thus producing a heavier nucleus. (Physicists call helium nuclei "alpha particles.")

agriculturist -- the main job description of our ancestors beginning some 10,000 years ago, namely those who mastered farming.

amino acid -- an organic molecule containing carboxyl and amino groups, of which 20 different types form the building blocks of all proteins comprising life on Earth.

angular momentum -- the tendency of an object to keep spinning or moving in a circle.

artificial intelligence -- the study of problem solving and decision making by machines in a way often done by humans.

assumptions of mediocrity -- the reasoned idea that we are not alone in the Universe; rather, given the enormity of space and the vastness of time, life arises in many cosmic locations.

atom period -- a time interval in the early Universe when some elementary particles began to cluster, thus fashioning the first atoms.

Australopithecus -- the designation given to those prehuman creatures having a mixture of ape-like and human-like qualities, and who live several million years ago.

autotroph -- any organism that survives on inorganic matter and an external energy source, such as photosynthesizing plants the world over.

axon -- the main extrusion of a neuron which acts as a transmitter of information.

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big bang -- a popular term describing the explosive start of the Universe.

biological evolution -- the changes, from generation to generation, experienced by life forms throughout the history of life on Earth.

bipedal -- an adjective meaning "having two feet" and/or "an ability to walk on two legs."

black hole -- a region containing a huge amount of mass compacted into an extremely small volume, thus making its pull of gravity so strong that not even light can escape--hence its name.

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carbonaceous chondrite -- a meteorite having embedded pebble-sized granules which contain significant quantities of organic (carbon-rich) matter.

cell -- the simplest type of clustered matter having the common attributes of life--birth, metabolism, and death.

chemical evolution -- the prebiological changes that transformed simple atoms and molecules into the more complex chemicals needed for the origin of life.

closed Universe -- a model Universe that stops expanding at some time in the future, after which it contracts to a point much like that from which it began.

collision theory -- the idea, now out of favor, that the planets formed from hot streaming debris torn from the Sun during a near-collision or close encounter with another passing star.

condensation theory -- the idea, broadly accepted today, that the planets originated from gravitationally contracting and chemically condensing eddies as a natural by-product of the formation of the Sun.

consciousness -- that property of human nature generally, or of the mind specifically, that grants us self-awareness and a sense of wonder.

cosmic background radiation -- a weak, electromagnetic (mostly radio) signal that permeates all of space, thought to be relic radiation of the big bang.

cosmic evolution -- the sum total of all the many varied changes in the assembly and composition of radiation, matter, and life throughout the history of the Universe.

cosmology -- the study of the Universe on the grandest scale, especially its origin, evolution, and destiny.

critical universal density -- the density of matter above which the Universe is closed and below (or equal to) which the Universe is open.

cultural evolution -- the changes in the ways, means, actions and ideas of societies, including the transmission of same from one generation to another.

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dehydration condensation -- the linking of two or more amino acids by means of removing water.

DNA -- an acronym for deoxyribonucleic acid, a long, helical, self-replicating molecule resident chiefly in biological nuclei, and mainly responsible for transmitting hereditary information and for the building of proteins.

dendrite -- one of a network of extrusions of a neuron which acts as a receiver of information.

Drake equation -- a mathematical formula that attempts to evaluate the prospects for technologically intelligent life in the Milky Way Galaxy.

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electromagnetic force -- the force that binds charges of opposite electric charge and repels charges of identical electric charge.

eukaryote -- a life form whose cells have well-developed biological nuclei.

event horizon -- a region within which no event can ever be seen, heard, or known by anyone outside; also termed the "surface" of a black hole.

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fault -- a zone of weakness where crustal rocks dislodge (as in earthquakes) or mantle rocks upwell (as in volcanos).

fermentation -- the extraction of energy via the capture and chemical breakdown of small molecules.

fossil -- the hardened remains of a dead organism whose outlines or bony features are preserved in ancient rocks.

fragmentation -- developing inhomogeneities in the gas density of a cloud which eventually breaks down into smaller clumps of matter within the cloud.

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galaxy -- a colossal collection of billions of stars and interstellar matter, held together by gravity; the Milky Way is one such galaxy.

galaxy period -- a time interval in the relatively early history of the Universe when the galaxies formed.

gene -- a segment of any DNA molecule containing information for the construction of one protein, hence responsible for directing inheritance from generation to generation.

gene pool -- The spread or distribution of the variations or traits among a given population of a species; all the genes in a given population.

genetic code -- an encyclopedic blueprint of the physical and chemical properties of all of an organism's cells and all of its functions.

genetics -- the study of genes, especially how they operate and change.

geography -- the study of positions, shapes, sizes, and numerous other qualities of Earth's continents.

grand unified theory -- an idea that three forces--the electromagnetic force, the strong nuclear force, and the weak force--are different manifestations of one and the same force.

gravitational force -- the force that holds matter together on large scales, such as stars within galaxies, atoms within stars, and people on Earth.

gravitational instability -- a condition whereby an object's (inward-pulling) gravitational potential energy exceeds its (outward-pushing) thermal energy, thus causing the object to infall.

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habitable zone -- a three-dimensional region of "comfortable" temperatures that surrounds every star.

hadron period -- a very early time interval in the history of the Universe when heavy, strongly interacting, elementary particles, such as protons and neutrons, were the most abundant type of matter.

Hayashi track -- an evolutionary stage of a protostar about to become a main-sequence star, and named after the Japanese astronomer who first studied such changes in detail.

helium flash -- the rapid onset of helium fusion in a red giant star.

heredity -- the transmission of genetic traits from parents to offspring, thus ensuring the preservation of certain characteristics among future generations of a species.

heterotroph -- any organism requiring organic matter for food, such as primitive cells that survived by absorbing acids and bases floating on primordial seas.

Homo erectus -- The species designation given to all human creatures who lived from roughly 0.3 to 1 million years ago; literally, the Latin means "erect man."

Homo sapiens -- The species designation given to all human creatures who lived during approximately the past 300,000 years, including ourselves; literally, the Latin means "wise man."

Hubble's constant -- the proportionality factor between the distance of a galaxy and velocity with which it recedes; currently taken to be about 22 kilometers/second/million light-years.

Hubble's law -- an empirical finding linking the distance of a galaxy and the velocity with which it recedes.

hunter-gatherer --the main job description of our ancestors during most of the past few million years, namely those who survived by hunting and gathering food.

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ice age -- a period of cool, dry climate that intermittently plagues planets, causing, in the case of Earth, a long-term buildup of ice far from the poles.

inflation -- a period of extremely rapid expansion of the Universe shortly after the Universe originated.

invertebrate -- a backbone-less organism.

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Kelvin-Helmholtz contraction phase -- an early evolutionary stage of an interstellar cloud fragment about to become a protostar.

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lepton period -- a very early time interval in the history of the Universe when the lightweight, weakly interacting, elementary particles, such as electrons and neutrinos, were the most abundant type of matter.

linear momentum -- the tendency of an object to keep moving in a straight line.

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Matter Era -- a period in the history of the Universe (including now) when the density of energy contained within matter exceeded the density of energy contained within radiation.

multicell -- a cluster of cells that collaborate with other cells.

mutation -- a random, microscopic change in one or more genes of an organism, transmissible by replication.

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natural selection -- the process whereby those life forms having advantageous traits are able to adapt to a changing environment, thereby surviving, reproducing, and passing on to their descendants those favorable traits which then accumulate in the population over time.

nebular theory -- the idea that the Solar System originated in a contracting, swirling cloud of gas that left behind a concentric series of rings from which the planets formed.

neuron -- a biological, or nerve, cell in a brain.

neutron star -- an extremely compact ball of neutrons having the mass of a star but a size smaller than a planet.

nova -- a star that rapidly brightens while expelling a small fraction of its matter, after which it slowly fades back to normal.

nuclear transformation -- changes in atomic nuclei owing to the reaction of one nucleus with another nucleus.

nuclear force -- the force that binds atomic nuclei.

nucleic acid -- a class of long-chain, organic molecules, made by grouping many nucleotides and often inhabiting the biological nuclei of cells.

nucleotide base -- one of five such molecules that comprise the building blocks of all nucleic acids within genes that transmit hereditary characteristics from one generation of life to the next.

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oceanography -- the study of the ocean's motion, history, and physical and chemical behavior.

open Universe -- a model Universe that expands forever.

oscillating Universe -- a model Universe that continuously cycles between expansion and contraction.

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paleoanthropology -- the study of prehistoric humanity.

paleomagnetism -- the study of ancient magnetism.

paleontology -- the study of the fossilized remains of dead organisms.

panspermia -- a theory that stipulates germs to be everywhere in the Universe, and that primitive life on Earth originated when some of those germs came to our planet from outer space.

photodisintegration -- the breakdown of heavy nuclei by means of intense heat.

photosynthesis -- the extraction of energy from ordinary sunlight when that light stimulates carbon dioxide and water to change into oxygen and carbohydrates.

planet -- a rocky and/or gaseous body, generally much smaller and cooler than a star; the Earth is one such planet.

planetary evolution -- the changes in the physical and chemical properties of planets during the course of their histories.

planetary nebula -- a twofold object comprising an old, yet hot white-dwarf star surrounded by a thin, ionized shell of expanding gas.

planetesimal -- an asteroid-sized blob of matter that gradually collided with others in the formative stages of the Solar System, thus fabricating the planets.

plate tectonics -- the study of plate movements which are thought to be responsible for many of the major geological features on planet Earth; popularly termed "continental drift."

primordial nucleosynthesis -- element building that occurred in the early Universe when the nuclei of primordial matter collided and fused with one another.

prokaryote -- a life form whose single cell lacks a well-developed biological nucleus.

protein -- a class of large, organic molecules, made of many amino acids and inhabiting the cytoplasm of cells.

proteinoid microsphere -- a microscopic protein-like cluster of molecules rich in amino acids.

protogalaxy -- a forerunner of a present-day galaxy, also sometimes termed a "baby galaxy."

protoplanet -- a forerunner, or progenitor, of a genuine planet.

protostar -- an embryonic condensation of interstellar matter perched at the dawn of star birth.

pulsar -- a compact, star-like object that emits rapid and periodic pulses of radiation, and which is thought to be a neutron star.

punctuated equilibrium -- the idea that life's species remain essentially unchanged for long periods of time, after which they change rapidly in response to sudden, drastic changes in the environment.

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quark -- a fractionally charged, basic building block of protons, neutrons, and many other elementary particles.

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Radiation Era -- a period in the early Universe when the density of energy contained within radiation exceeded the density of energy contained within matter.

Ramapithecus -- the designation given to a possible ancestor of both the australopithecines and humans, dating back roughly 10 million years.

r-process --element building that occurs in highly evolved stars when a neutron is "rapidly" captured by a nucleus.

red giant star -- an old, bright star, much larger in size and cooler than the Sun.

respiration -- a chemical process whereby cells use oxygen to release energy; a technical term for "breathing."

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scientific method -- the investigative technique used by all natural scientists throughout the world; in general, some data or ideas are first gathered, then a theory is proposed to explain them, and finally an experiment is devised to test the theory.

s-process -- element building that occurs in highly evolved stars when a neutron is "slowly" captured by a nucleus.

shock wave -- a rapidly rushing shell of gas that tends to push aside and sometimes implode matter in its wake.

secondary atmosphere -- gases that a planet exhales from its interior after having lost its primary, or primordial, atmosphere.

singularity -- a superhot, superdense state of matter, where the known laws of physics are likely to break down.

Solar System -- the collection of planets, moons, and related objects orbiting about the Sun; the Earth is one such member of the Solar System.

speciation -- the change of a single species into two or more new species; also termed "disruptive selection."

species -- a classification of life denoting not only individuals that are structurally similar but also able to mate among themselves and produce fertile offspring.

spontaneous generation -- the theory, now out of favor, that life forms suddenly emerged fully developed from peculiar arrangements of non-living matter.

star -- a gaseous object so hot that its core fuses lighter nuclei into heavier nuclei; the Sun is one such star.

stellar period -- a time interval in the history of the Universe (including now) when the stars form.

stellar evolution -- the changes experienced by stars as they originate, mature, and terminate.

stellar nucleosynthesis -- element building that occurs in stars when nuclei collide and fuse with one another.

supernova -- an explosive death of a massive star whose glowing debris produce for a short time a great brightening.

supernova remnant -- the remains of a supernova, namely glowing debris scattered over a light-year or more.

synapse -- a microscopic gap separating an axon of one neuron from a dendrite of another neuron.

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turbulence -- the disordered, irregular motion of matter, so complex as to defy description except in a statistical manner.

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unicell -- a single cell that does not collaborate with other cells.

Universe -- the totality of all space, matter, and energy.

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vertebrate -- an organism having a backbone, and including fishes, amphibians, reptiles, and mammals.

virus -- the smallest and simplest entity that sometimes appears to be alive.

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water hole -- the radio domain between the 21-centimeter wavelength spectral line of hydrogen (H) and the 18-centimeter wavelength spectral lines of the hydroxyl molecule (OH).

weak force -- the force that governs the change of one kind of elementary particle into another.

white dwarf star -- an old, dim star, much smaller in size and hotter than the Sun.

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