 |
 |
 |
 |
 |
 |
 |
 |
 |
 |
| . |  |
. |
A Thermodynamic History Of Universe, Earth And Humans
A new book by Gino Segre, a theoretical physicist at the University of Pennsylvania, makes temperature the theme of a journey through science, history and culture, revealing the surprisingly deep ways in which this subtle parameter has shaped humans and their world. Segre's first book -- "A Matter of Degrees: What Temperature Reveals About the Past and Future of Our Species, Planet, and Universe" (Viking, 2002) -- moves from the blazing hearts of faraway stars to physicists' drive toward absolute zero, from global warming to heat-sensitive proteins in the human body. "Segre combines a historical perspective and a broad command of modern science to provide a lucid and novel synthesis of the concept of temperature," said science writer John Harte, author of "Consider a Spherical Cow" and "The Green Fuse." Of all the fundamental measures of our universe, Segre identifies temperature as the newcomer. First measured in the 17th century, millennia after time and distance were first quantified, temperature is, in Segre's view, an appropriate yardstick for measuring the progress of humanity. "If I were to employ temperature as my record for a narrative of civilization," Segre writes, "I would cite the ever-hotter fires humans made as they moved ... from the Stone Age's first fires to charcoal and then to the bellows that produced bronze and iron. "Going further, I would reach the steam engine, the nineteenth century's great Bessemer furnaces that made steel, and finally the Nuclear Age. ... For the past 200 years, I could use as a marker the ever-lower temperatures achieved in laboratories as, one by one, all known species of gas were liquefied. As the millennium came to an end, the low-temperature scale reached billionths of a degree above absolute zero." Ever wonder what's so special about 98.6 degrees Fahrenheit, or why we consider room temperature to be around 70 degrees? Segre explains that people feel most comfortable in settings some 20 to 30 degrees below body temperature because that differential produces a comfortable rate of heat loss. Perhaps it is not a coincidence that humans emerged two million years ago in parts of Africa where median temperatures are in the low 70s. In another passage linking temperature to human evolution, Segre marvels at how scattered radioactivity in the Earth's crust has essentially given rise to creatures sophisticated enough to ponder radioactivity. "The radioactive alpha particle decay of a few kinds of nuclei heats the Earth's crust, which convectively creates fire just below the surface," he writes. "Forced up through the ocean bottom in hydrothermal vents, this activity somehow sustains life that evolves to create creatures that think about radioactivity." Far beyond the confines of humanity, Segre describes the history of our universe in terms of its evolution from the 100-billion-degree Big Bang to the average of a few degrees above absolute zero found across today's cold, sparse universe. Along the way, the warm interstellar dust near our newborn sun condensed into moderately sized planets, while much lower temperatures further afield froze the primordial soup into giants like Saturn and Jupiter. Segre, a Penn professor since 1967, describes physics as his "family business." Nephew of particle physicist and Nobel laureate Emilio Segre, he is also the brother, son-in-law, uncle and cousin of physicists. He has served as director of theoretical physics at the National Science Foundation and has been honored by the Alfred P. Sloan and Guggenheim foundations. Related Links University of Pennsylvania SpaceDaily Search SpaceDaily Subscribe To SpaceDaily Express 
Writing in the Infrared
Scottsdale - Jul 04, 2002Ideas and technologies that were recently only the wildest speculation now are hotly, even violently, debated worldwide. But not the prospect of a spacefaring future. While many address opportunities in space, their work seems to fall into a cultural blind spot, present but unseen. It's as if they were writing in the infrared: something is there, discernable by anyone sufficiently attuned. The world at large, though, literally cannot see the writing on the wall.
|
|
| |||||||||
| The content herein, unless otherwise known to be public domain, are Copyright 1995-2016 - Space Media Network. All websites are published in Australia and are solely subject to Australian law and governed by Fair Use principals for news reporting and research purposes. AFP, UPI and IANS news wire stories are copyright Agence France-Presse, United Press International and Indo-Asia News Service. ESA news reports are copyright European Space Agency. All NASA sourced material is public domain. Additional copyrights may apply in whole or part to other bona fide parties. Advertising does not imply endorsement, agreement or approval of any opinions, statements or information provided by Space Media Network on any Web page published or hosted by Space Media Network. Privacy Statement All images and articles appearing on Space Media Network have been edited or digitally altered in some way. Any requests to remove copyright material will be acted upon in a timely and appropriate manner. Any attempt to extort money from Space Media Network will be ignored and reported to Australian Law Enforcement Agencies as a potential case of financial fraud involving the use of a telephonic carriage device or postal service. |
