miércoles, 26 de octubre de 2011

Vast Nebular Clouds of Organics --Support Biological View of the Universe

This worldview of the cosmos as a biological universe is a revolutionary perspective as profound a revision in our way of thinking as the Copernican and Darwinian revolutions. It is a worldview that believes that "planetary systems are common, that life originates wherever conditions are favorable, and that evolution culminates with intelligence."

As a species, we have been around for 200 thousand years, which is not remarkably long considering that Tyrannosaurs Rex existed for two and half million years. Yet in this very short time, the human imagination has led to a profound if still limited understanding of the laws of physics and our place in the universe.

The fundamental concept of the 21st century, the question of life beyond our planet, has exercised human imagination, and sometimes stirred irrational fears, since the ancient Greeks. The search for life  is our great secular meditation on the Other.

As we wrote in a post last year, these fears were in part responsible for the gruesome death of Giordano Bruno on February 17, 1600, when he was taken from his Inquisition prison cell in Castel S'ant Angelo across the Tiber from the Vatican, marched to the Campo dei Fiori, and burned at the stake in large part for his belief in an infinite number of inhabited worlds.

Today, some 400 years later, two mutually exclusive world views of our cosmos are at conflict; world views that infuses science fiction as well as popular culture and scientific debate. The first, the physical world view, believes that cosmic evolution ends in planets, stars, and galaxies; the second, the biological worldview, believes that the emergence of life and intelligence is pre-programmed into the laws and constants of physics, which function similar to cosmic DNA. Each results in vastly different implications for science, for society, and for human destiny.

The biological universe worldview is captured perfectly in famed physicist, Freeman Dyson comment that The more I examine the universe and study the details of its architecture, the more evidence I find that the universe in some sense must have known we were coming. It is a vision of the world as profound in its implications as that of Copernicus and Darwin.

Finally, there is the new, emerging worldview of Cambridge physicist, Sir Martin Rees, Lee Smolin ,and Richard Gott of Princeton who imagine  that in addition to planets, stars, and galaxies looms the "multiverse" -of than one universe, where "universe" is defined as everything we have seen, or can see.

The fact that the universe seems to be fine tuned for life has given birth to the poorly named "anthropic principle" -a misnomer because it is relevant to the existence of all forms of life in the universe, not just humankind, and therefore is not anthropic.

These divergent worldviews fuel our daily press with feature news stories about fierce battles for congressional cutbacks in space exploration; essays on the urgency of space colonization, terraforming, the galactic certainty of eventual asteroid impacts, and a new focus on searching for non-carbon-based life forms mainstream media such as the in the New York Times and History Channel specials on the Universe and the search for  life with pros, cons, and all views in between.

Many of the most exciting subjects of contemporary science appeared first as products of brilliant science fiction: H.G.Wells wrote "The Time Machine" in 1895, ten  years before Einstein imagined a universe of curved space-time -of special relativity. At that time, with the Newton's theory, time travel looked impossible. But with the Einstein's theory of special relativity moving clocks tick slowly, and later, with the general theory of relativity, space and time are bendable.

A similar result came about with Carl Sagan's novel and blockbuster film Contact about wormholes. He asked Kip Thorne at Cal Tech to examine whether his wormhole physics make sense. Thorne looked into the physics and found that circumstances and solutions might allow a time machine to visit the past.

Arthur C. Clarke, in  2001: A Space Odyssey (1968) played out a universe populated by advanced, machine-based intelligence . The Polish science fiction author Stanislaw Lem represents yet another vision: in Solaris (1961) and His Master's Voice (1968) he argues that we may be unable to comprehend, much less communicate, which lends special weight to a focus on searching for non-carbon-based life forms.

Perhaps an accurate vision of our future be found in the science fiction of Alastair Reynolds, a young, recently retired scientist with the European Space Agency. Several critics believe he is on track to be the next Arthur C. Clarke (2001 -A Space Odyssey). His trilogy a "vision of a future dominated by artificial intelligence that trembles with the ultimate cold of the dark between the stars." -asks the great question: if there is intelligent life out there, how come we never encountered it?

Biological or physical? We won't be burned at the stake, but we'll bet that if past is prelude, it's a biological universe, with all its profound implications for the future of the human species.

In his masterpiece, The Ancestor's Tale, famed Oxford evolutionary biologist Richard Dawkins reflected on the sheer wonder of the emergence of life on Earth and the evolutionary process:

"The universe could so easily have remained lifeless and simple -just physics and chemistry, just the scattered dust of the cosmic explosion that gave birth to time and space. The fact that it did not -the fact that life evolved out of literally nothing, some 10 billion years after the universe evolved literally out of nothing -is a fact so staggering that I would be mad to attempt words to do it justice. And even that is not the end of the matter. Not only did evolution happen: it eventually led to beings capable of comprehending the process by which they comprehend it."

Steven Dick, NASA's chief historian and former astronomer of the United States Naval Observatory, has a vastly different view of the emergence of life in the universe: to Dick the emergence of life and the evolution of intelligence is literally pre-programmed by the laws and constants of physics, which function similar to cosmic DNA.

The emergence of life and intelligence, according to Dick, was coded into the cosmic playbook from the first moment of the Big Bang. Intelligent life is destined to eventually dominate the cosmos and ultimately to serve as the instrument of cosmic replication.

In his famous essay, and our World View at the Turn of the Millennium, Dick argues that at the dawn of the 21st century calls for us to take into account the Copernican principle that life on earth and humanity is in no way physically central in the universe: "we are located on a small planet around a star on the outskirts of the Milky Way galaxy."

Underpinning the biological view of the universe are recent findings by the Herschel Space Observatory, which has revealed the chemical fingerprints of potential life-enabling organic molecules in the Orion Nebula, a nearby stellar nursery in our Milky Way galaxy and one of the most prolific chemical factories in space, although the full extent of its chemistry and the pathways for molecule formation are not well understood.

This detailed-spectrum, obtained with the Heterodyne Instrument for the Far Infrared (HIFI) - one of Herschel's three innovative instruments - demonstrates the gold mine of information that Herschel-HIFI is providing on how organic molecules form in space, including a rich, dense pattern of "spikes", each representing the emission of light from a specific molecule in the Orion Nebula.  By sifting through the pattern of spikes in this spectrum, astronomers have identified a few common molecules that appear everywhere in the spectrum. The identification of the many other emission lines is currently ongoing.

A characteristic feature of the Orion spectrum is the spectral richness: among the molecules that can be identified in this spectrum are water, carbon monoxide, formaldehyde, methanol, dimethyl ether, hydrogen cyanide, sulfur oxide, sulfur dioxide and their isotope analogues. It is expected that new organic molecules will also be identified.

"This HIFI spectrum, and the many more to come, will provide a virtual treasure trove of information regarding the overall chemical inventory and on how organics form in a region of active star formation. It harbors the promise of a deep understanding of the chemistry of space once we have the full spectral surveys available," said Edwin Bergin of the University of Michigan, principal investigator of the HEXOS Key Program on Herschel.

HIFI was designed to provide extremely high-resolution spectra and to open new wavelength ranges for investigation, which are inaccessible to ground-based telescopes. "HIFI's unprecedented high resolution and stability allows us to construct very detailed models of the density and temperature structure of star-forming clouds," said Tom Phillips of the California Institute for Technology. "This view allows us to pierce the veil of star formation and more directly study the chemistry associated with the birth of stars, planets, and in some sense, life."

Identification of the many spectral features visible in the Orion spectrum with transitions of particular molecular species requires sophisticated molecular spectroscopy databases, which collect the results from many years of laboratory spectroscopy work. The assignments for this HIFI spectrum were made using the Cologne Database of Molecular Spectroscopy (CDMS) and an equivalent database maintained at NASA's Jet Propulsion Laboratory.

Source: The Daily Galaxy

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