Comet
My Thoughts :
Details :
- Author : Carl Sagan
- Release Date : 1980
- Publisher : Random House
Favourite Quotes :
Our universe is a sorry little affair unless it has in it something for every age to investigate … Nature does not reveal her mysteries once and for all. —Seneca, Natural Questions,Book 7, first century (1) Lost somewhere between immensity and eternity is our tiny planetary home.(23) Occasionally someone remarks on what a lucky coincidence it is that the Earth is perfectly suitable for life—moderate temperatures, liquid water, oxygen atmosphere, and so on. But this is, at least in part, a confusion of cause and effect. We earthlings are supremely well adapted to the environment of the Earth because we grew up here. (41) If artificial selection can make such major changes in so short a period of time, what must natural selection, working over billions of years, be capable of? The answer is all the beauty and diversity of the biological world. Evolution is a fact, not a theory. (45) The secrets of evolution are death and time—the deaths of enormous numbers of lifeforms that were imperfectly adapted to the environment; and time for a long succession of small mutations that were by accident adaptive, time for the slow accumulation of patterns of favorable mutations. (49) What a marvelous cooperative arrangement—plants and animals each inhaling the other’s exhalations, a kind of planet-wide mutual mouth-to-stoma resuscitation, the entire elegant cycle powered by a star 150 million kilometers away. (56) The evolution of life requires a more or less precise balance between mutation and selection. (59) A change in a single DNA nucleotide causes a change in a single amino acid in the protein for which that DNA codes. (59) There is still much to be understood about the origin of life, including the origin of the genetic code. But we have been performing such experiments for only some thirty years. Nature has had a four-billion-year head start. All in all, we have not done badly. (62) Over the dying embers of the campfire, on a moonless night, we watched the stars. (67) The lunar surface offers eloquent testimony of a previous age of the destruction of worlds, now billions of years gone. (117) The suppression of uncomfortable ideas may be common in religion and politics, but it is not the path to knowledge. (125) With insufficient data, it is easy to go wrong. (130) With searing heat, crushing pressures, noxious gases and everything suffused in an eerie, reddish glow, Venus seems less the goddess of love than the incarnation of hell. (133) Our lovely blue planet, the Earth, is the only home we know. Venus is too hot. Mars is too cold. But the Earth is just right, a heaven for humans. (138) ters that affect the entire human family? Do we value short-term advantages above the welfare of the Earth? Or will we think on longer time scales, with concern for our children and our grandchildren, to understand and protect the complex life-support systems of our planet? The Earth is a tiny and fragile world. It needs to be cherished. (139) xistence of the fabled canals, turned out to be bankrupt, his depiction of the planet had at least this virtue: it aroused generations of eight-year-olds, myself among them, to consider the exploration of the planets as a real possibility, to wonder if we ourselves might one day voyage to Mars. (150) One way or another, I knew, this was a world to which we would return.(162) Large plants and animals did not colonize the land until the last 10 percent of Earth history. And yet for three billion years there were microorganisms everywhere on Earth. To look for life on Mars, we must look for microbes. (163) And if there is no life on Mars, a planet rather like the Earth, we must understand why—because in that case, as Vishniac stressed, we have the classic scientific confrontation of the experiment and the control. (170) -- Or perhaps there are living things that do not have a solvent system at all—solid-state life, where there are electrical signals propagating rather than molecules floating about. (172) If mere is life on Mars, I believe we should do nothing with Mars. Mars then belongs to the Martians, even if the Martians are only microbes. (175) If a faithful account was rendered of Man’s ideas upon Divinity, he would be obliged to acknowledge, that for the most part the word “gods” has been used to express the concealed, remote, unknown causes of the effects he witnessed; that he applies this term when the spring of the natural, the source of known causes, ceases to be visible: as soon as he loses the thread of these causes, or as soon as his mind can no longer follow the chain, he solves the difficulty, terminates his research, by ascribing it to his gods … When, therefore, he ascribes to his gods the production of some phenomenon … does he, in fact, do any thing more than substitute for the darkness of his own mind, a sound to which he has been accustomed to listen with reverential awe? —Paul Heinrich Dietrich, Baron von Holbach, Système de la Nature, London, 1770 (213) --- paperpack --- They are frightened of the flame. But we are not frightened. The flame is ours. We take care of the flame. The flame takes care of us. [190] I wish I knew which was true. I don’t like not knowing. [193] The scientific world view works so well, explains so much and resonates so harmoniously with the most advanced parts of our brains that in time, I think, virtually every culture on the Earth, left to its own devices, would have discovered science. [196] A major problem in the contemporary (political) Third World is that the educated classes tend to be the children of the wealthy, with a vested interest in the status quo, and are unaccustomed either to working with their hands or to challenging conventional wisdom. Science has been very slow to take root. [212] We make our world significant by the courage of our questions and by the depth of our answers. [219] The beach also reminds us of time. The world is much older than the human species. [220] the total number of stars in the universe is greater than all the grains of sand on all the beaches of the planet Earth.[221] We had the sky, up there, all speckled with stars, and we used to lay on our backs and look up at them, and discuss about whether they was made, or only just happened. —Mark Twain, Huckleberry Finn [241] A star is a phoenix, destined to rise for a time from its own ashes. [252] All the elements of the Earth except hydrogen and some helium have been cooked by a kind of stellar alchemy billions of years ago in stars, some of which are today inconspicuous white dwarfs on the other side of the Milky Way Galaxy. The nitrogen in our DNA, the calcium in our teeth, the iron in our blood, the carbon in our apple pies were made in the interiors of collapsing stars. We are made of starstuff.[255] The origin and evolution of life are connected in the most intimate way with the origin and evolution of the stars. First: The very matter of which we are composed, the atoms that make life possible, were generated long ago and far away in giant red stars. The relative abundance of the chemical elements found in the Cosmos matches the relative abundance of atoms generated in stars so well as to leave little doubt that red giants and supernovae are the ovens and crucibles in which matter has been forged. The Sun is a second- or third-generation star. All the matter in it, all the matter you see around you, has been through one or two previous cycles of stellar alchemy. Second: The existence of certain varieties of heavy atoms on the Earth suggests that there was a nearby supernova explosion shortly before the solar system was formed. But this is unlikely to be a mere coincidence; more likely, the shock wave produced by the supernova compressed interstellar gas and dust and triggered the condensation of the solar system. Third: When the Sun turned on, its ultraviolet radiation poured into the atmosphere of the Earth; its warmth generated lightning; and these energy sources sparked the complex organic molecules that led to the origin of life. Fourth: Life on Earth runs almost exclusively on sunlight. Plants gather the photons and convert solar to chemical energy. Animals parasitize the plants. Farming is simply the methodical harvesting of sunlight, using plants as grudging intermediaries. We are, almost all of us, solar-powered. Finally, the hereditary changes called mutations provide the raw material for evolution. Mutations, from which nature selects its new inventory of life forms, are produced in part by cosmic rays—high-energy particles ejected almost at the speed of light in supernova explosions. The evolution of life on Earth is driven in part by the spectacular deaths of distant, massive suns. [256] The Sun warms us and feeds us and permits us to see. It fecundated the Earth. It is powerful beyond human experience. Birds greet the sunrise with an audible ecstasy. Even some one-celled organisms know to swim to the light. Our ancestors worshiped the Sun,* and they were far from foolish. And yet the Sun is an ordinary, even a mediocre star. If we must worship a power greater than ourselves, does it not make sense to revere the Sun and stars? [266] Some foolish men declare that a Creator made the world. The doctrine that the world was created is ill-advised, and should be rejected. If God created the world, where was He before creation?… How could God have made the world without any raw material? If you say He made this first, and then the world, you are faced with an endless regression … Know that the world is uncreated, as time itself is, without beginning and end. And it is based on the principles … —The Mahapurana (The Great Legend), Jinasena (India, ninth century) [269] That we live in a universe which permits life is remarkable. That we live in one which destroys galaxies and stars and worlds is also remarkable. The universe seems neither benign nor hostile, merely indifferent to the concerns of such puny creatures as we. [275] It is said that men may not be the dreams of the gods, but rather that the gods are the dreams of men. [285] Knowing a great deal is not the same as being smart; intelligence is not information alone but also judgment, the manner in which information is co-ordinated and used. [297] Our passion for learning, evident in the behavior of every toddler, is the tool for our survival. [306] Emotions and ritualized behavior patterns are built deeply into us. They are part of our humanity. But they are not characteristically human. Many other animals have feelings. What distinguishes our species is thought. The cerebral cortex is a liberation [306] No longer at the mercy of the reptile brain, we can change ourselves. [306] A book is made from a tree. --- One glance at it and you hear the voice of another person—perhaps someone dead for thousands of years. Across the millennia, the author is speaking, clearly and silently, inside your head, directly to you. [307] For the price of a modest meal you can ponder the decline and fall of the Roman Empire, the origin of species, the interpretation of dreams, the nature of things. Books are like seeds. They can lie dormant for centuries and then flower in the most unpromising soil. [308] If information could be passed on merely by word of mouth, how little we should know of our past, how slow would be our progress! Everything would depend on what ancient findings we had accidentally been told about, and how accurate the account was. Past information might be revered, but in successive retellings it would become progressively more muddled and eventually lost. Books permit us to voyage through time, to tap the wisdom of our ancestors. [309] Public libraries depend on voluntary contributions. I think the health of our civilization, the depth of our awareness about the underpinnings of our culture and our concern for the future can all be tested by how well we support our libraries. [309] “What are you? From where did you come? I have never seen anything like you.” The Creator Raven looked at Man and was … surprised to find that this strange new being was so much like himself. —An Eskimo creation myth [319] If civilizations tend to destroy themselves soon after reaching a technological phase, there might be no one for us to talk with but ourselves. And that we do but poorly. Civilizations would take billions of years of tortuous evolution to arise, and then snuff themselves out in an instant of unforgivable neglect. [331] To what purpose should I trouble myself in searching out the secrets of the stars, having death or slavery continually before my eyes? —A question put to Pythagoras by Anaximenes (c. 600 B.C.), according to Montaigne [346] How vast those Orbs must be, and how inconsiderable this Earth, the Theatre upon which all our mighty Designs, all our Navigations, and all our Wars are transacted, is when compared to them. A very fit consideration, and matter of Reflection, for those Kings and Princes who sacrifice the Lives of so many People, only to flatter their Ambition in being Masters of some pitiful corner of this small Spot. —Christiaan Huygens, New Conjectures Concerning the Planetary Worlds, Their Inhabitants and Productions, c. 1690 [346] Every thinking person fears nuclear war, and every technological state plans for it. Everyone knows it is madness, and every nation has an excuse. There is a dreary chain of causality: The Germans were working on the bomb at the beginning of World War II; so the Americans had to make one first. If the Americans had one, the Soviets had to have one, and then the British, the French, the Chinese, the Indians, the Pakistanis … By the end of the twentieth century many nations had collected nuclear weapons. They were easy to devise. Fissionable material could be stolen from nuclear reactors. Nuclear weapons became almost a home handicraft industry.[349] When our well-being is threatened, when our illusions about ourselves are challenged, we tend—some of us at least—to fly into murderous rages. And when the same provocations are applied to nation states, they, too, sometimes fly into murderous rages, egged on often enough by those seeking personal power or profit. But as the technology of murder improves and the penalties of war increase, a great many people must be made to fly into murderous rages simultaneously for a major war to be mustered. [353] Henry Kissinger, a contemporary politician, wrote: “Deterrence depends, above all, on psychological criteria. For purposes of deterrence, a bluff taken seriously is more useful than a serious threat interpreted as a bluff.” [355] According to one estimate, the corporate profits in military weapons procurement are 30 to 50 percent higher than in an equally technological but competitive civilian market. Cost overruns in military weapons systems are permitted on a scale that would be considered unacceptable in the civilian sphere. In the Soviet Union the resources, quality, attention and care given to military production is in striking contrast to the little left for consumer goods. According to some estimates, almost half the scientists and high technologists on Earth are employed full- or part-time on military matters. Those engaged in the development and manufacture of weapons of mass destruction are given salaries, perquisites of power and, where possible, public honors at the highest levels available in their respective societies. The secrecy of weapons development, carried to especially extravagant lengths in the Soviet Union, implies that individuals so employed need almost never accept responsibility for their actions. They are protected and anonymous.Military secrecy makes the military the most difficult sector of any society for the citizens to monitor. If we do not know what they do, it is very hard for us to stop them. And with the rewards so substantial, with the hostile military establishments beholden to each other in some ghastly mutual embrace, the world discovers itself drifting toward the ultimate undoing of the human enterprise. [357] Mammals characteristically nuzzle, fondle, hug, caress, pet, groom and love their young, behavior essentially unknown among the reptiles. If it is really true that the R-complex and limbic systems live in an uneasy truce within our skulls and still partake of their ancient predelictions, we might expect affectionate parental indulgence to encourage our mammalian natures, and the absence of physical affection to prod reptilian behavior. [359] We have held the peculiar notion that a person or society that is a little different from us, whoever we are, is somehow strange or bizarre, to be distrusted or loathed. Think of the negative connotations of words like alien or outlandish. And yet the monuments and cultures of each of our civilizations merely represent different ways of being human. [370] There will be no humans elsewhere. Only here. Only on this small planet. We are a rare as well as an endangered species. Every one of us is, in the cosmic perspective, precious. If a human disagrees with you, let him live. In a hundred billion galaxies, you will not find another. [370]Read : 23 July 2022 - 21 Aug 2022