Cosmology: star factories (Introduction)

by David Turell , Saturday, April 04, 2015, 14:42 (3522 days ago) @ Balance_Maintained

How our living elements come from the stars:-http://www.nytimes.com/2015/04/05/opinion/sunday/our-cosmic-selves.html?emc=edit_th_20150404&nl=todaysheadlines&nlid=60788861&_r=0--"That discovery is relatively recent. Four astrophysicists developed the idea in a landmark paper published in 1957. They argued that almost all the elements in the periodic table were cooked up over time through nuclear reactions inside stars — rather than in the first instants of the Big Bang, as previously thought. The stuff of life, in other words, arose in places and times somewhat more accessible to our telescopic investigations.-"Since most of us spend our lives confined to a narrow strip near Earth's surface, we tend to think of the cosmos as a lofty, empyrean realm far beyond our reach and relevance. We forget that only a thin sliver of atmosphere separates us from the rest of the universe.-"But science continues to show just how intimately connected life on Earth is to extraterrestrial processes. In particular, several recent findings have further illuminated the cosmic origins of life's key ingredients.-"Take the element phosphorus, for example. It is a critical constituent of DNA, as well as of our cells, teeth and bones. Astronomers have long struggled to trace its buildup through cosmic history, because the imprint of phosphorus is difficult to discern in old, cool stars in the outskirts of our galaxy. (Some of these stellar “time capsules” contain the ashes of their forebears, the very first generation of stars that formed near the dawn of time.)-******-"Astrochemists are excited by this discovery because amino acids, which have been found already in some meteorites, form the basis of proteins. Meanwhile, last month, NASA scientists reported the creation of key DNA components in a laboratory experiment that simulated the space environment. Together, these findings raise the odds that life's building blocks were concocted in space and blended into the material that formed Earth and its planetary siblings.-"Amid the material comforts and the relentless distractions of modern life, the universe at large may appear remote, intangible and irrelevant, especially to those of us who are city dwellers. But the next time you catch a glimpse of the Milky Way in its true glory, from a dark outpost far from city lights, think of those countless stars as nuclear factories and the starless hazy patches as molecular breweries. It is not much of a stretch to imagine the inchoate seeds of life emerging in the distance."