From the prizewinning author who has been called "the greatest science writer in the world" comes this delightfully comprehensive and comprehensible report on how science today envisions the universe as a whole.
Timothy Ferris provides a clear, elegantly written overview of current research and a forecast of where cosmological theory is likely to go in the twenty-first century. He explores the questions that have occurred to even casual readers -- who are curious about nature on the largest
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From the prizewinning author who has been called "the greatest science writer in the world" comes this delightfully comprehensive and comprehensible report on how science today envisions the universe as a whole.
Timothy Ferris provides a clear, elegantly written overview of current research and a forecast of where cosmological theory is likely to go in the twenty-first century. He explores the questions that have occurred to even casual readers -- who are curious about nature on the largest scales: What does it mean to say that the universe is "expanding," or that space is "curved"? -- and sheds light on the possibility that our universe is only one among many universes, each with its own physical laws and prospects for the emergence of life.Frederick PatterThe Christian Science MonitorThe best popular science writer in the English language today.Jim HoltThe Wall Street JournalExcellent...a heroic synthesis of cosmic knowledge today.Owen GingerichThe New York Times Book ReviewA breathtaking wide canvas...Ferris is admirably lucid.Joel AchenbachThe Washington PostFerris...is a compassionate and clever guide...If there are more great discoveries to be made, Ferris would be someone you'd want around to explain them.From Chapter 1,The Shores of LightThe so-calledbig bangmodel arose from thinking about what an expanding universe would have been like in its infancy. The observable universe today is roughly 15 billion light-years in radius. When its radius was much smaller -- only one light-year, say -- all the matter in the universe must have been packed together in a lot less space. Any given quantity of matter, compressed to a higher density, gets hotter: That's why a penny, lifted off a railroad track moments after being flattened by a passing train, is hot to the touch, and why compressing air in a bicycle pump heats the air, making the pump warm. So it seems reasonable to imagine that the early universe may have been not only dense, but also hot. Very hot: When the universe was one second old, in this scenario, every spoonful of stuff was denser than stone and hotter than the center of the sun. The expansion and resultant cooling of the universe permitted the formation of atoms, molecules, galaxies, and living creatures. What we call matter is frozen energy. It froze because the universe, owing to its expansion, cooled.
The big bang theory implied that as the young universe expanded there should have come a time, nowadays reckoned at about five hundred thousand years after the beginning, when the primordial plasma thinned out sufficiently to become transparent to light. Physicists call this eventphoton decoupling,meaning that photons, the particles that constitute light and other forms of electromagnetic energy, were at this point set free. Thereafter they did not often interact with one another, or with matter, but went soaring unhampered through the constantly expanding reaches of cosmic space. Hence most of them should still be around today. Cosmic expansion would have stretched them out, increasing their wavelengths from those of light to the wavelengths we call microwave radio. In microwave frequencies it is convenient to express energy in terms of temperature -- as does, say, the instruction manual that accompanies a microwave oven -- so another way to reason through this argument is to say that the universe, having once been hot, should remain a bit warm even today. Physicists theorizing about the existence of thiscosmic microwave background,or CMB, calculated that it should have a temperature of about three degrees above absolute zero. They also noted that it would display a "black body" spectrum, as is dictated by the relevant quantum physics equations and that it should beisotropic,meaning that any observer, anywhere in the universe, should measure the background as having the same temperature everywhere in the sky. One can think of the CMB as a haz
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