Saturday, June 26, 2010

Not a Peep out of Alien Civilizations?, Consider Interstellar Migration

Under optimistic projections, we will set forth on the first interstellar voyage before 2100, perhaps within the expected life span of today’s children. According to pessimistic projections, for all intents and purposes human interstellar travel is impossible, and the reality is that “you can’t get there from here.” The problem, given present-day technology, is distance. Distances between the stars (including our own Sun and its neighbors) are measured in light-years. Since light travels at the speed of 300,000 kilometers per second, one light-year is almost 10 trillion kilometers. (A trillion is a million million.) With the exception of astronomers, who are taught to think big, it is almost impossible for people to grasp the enormity of such distances. Eugene Mallove and Gregory Matloff note that the nearest star, Proxima Centauri, 4.3 light-years from here, is about 273,000 times the distance from Earth to the Sun. 1 If we represent the Sun by a circle with a diameter of 1 centimeter, Earth would be a dot with a diameter of .1 millimeter, located 1 meter away. Pluto would be 42 meters from the Sun, and Proxima Centauri would be 292 kilometers farther out.

Starflight 

The challenge of interstellar travel is covering immense distances within a time frame that keeps the journey meaningful. We have already launched interstellar probes. Pioneer 10 and 2 have completed their work within our solar system and will make their closest approach to other stars as early as 32,600 or as late as 497,000 years from now. 2 Since their primary function is to explore our solar system, they are not taking the most direct route to our nearest neighbor. If we could travel at the speed of light, then 4.3 years’ travel time to Proxima Centauri might not be too bad. Given what we know right now, however, we can’t come close to this. Estimated starship speeds are measured in hundredths of the speed of light, and a ship that topped out at .06 times the speed of light would be a snappy performer. Yet because it would take years to accelerate to this speed (and years to decelerate in order to stop at the destination) average speed would be much lower than this. By many estimates, even a “short” interstellar voyage could take centuries. This might not bother an automated probe, but could cause problems for humans. 
Detailed planning for interstellar spacecraft has been under way since before the first orbital flights. Over the years, many different designs have been brought forward. Some of these are based upon optimistic predictions about future science and technology, but others involve either known technologies and construction techniques or ones that should soon become available. Like airplane, ship, and automobile designs, starship plans reflect trade-offs among size, fuel requirements, and speed. Without question, nuclear rockets are the most promising.
We can divide interstellar missions into two categories: multigeneration and single generation. All starship designs that use known or reasonably demonstrable technologies will require multigeneration missions, but some, known as slowships, will require more generations to travel to a given star than will others, known as fastships. As for singlegeneration interstellar missions, many space scientists would say that we have only hazy or wishful ideas about how to accomplish them, if they are possible at all.

This Brings us to the most  fundamental and critical question regarding the interstellar migration. If a multigeneration Interstellar ship were to leave for another solar system today, would you consider volunteering for the greater good of humanity? Use the opinions poll and let us know!

In the meanwhile, enjoy these artist's renderings of futuristic interstellar vehicles.

Friday, June 25, 2010

Has Life Originated Elsewhere and will it End?


If the genetic code is universal, it is probably because every organism that has succeeded in living up till now is descended from one single ancestor. But, it is impossible to measure the probability of an event that occurred only once. 
Fran├žois Jacob, The Logic of Life (1973)

The wave of optimism that followed the Miller experiment in 1953 has been replaced today by more subdued attitudes. Solving the mysteries of the emergence of life on Earth is now seen as a very difficult proposition. In the face of this, some have proposed that life may have originated elsewhere in the solar system, or even somewhere else in our galaxy. Proponents of this view include the famous biophysicist Francis Crick of DNA fame (his statement on that question seems to have been tongue-in-cheek) and the equally famous cosmologist Fred Hoyle (not so tongue-in-cheek). 

Echoes of Panspermia

In the nineteenth century, the well-known Swedish chemist Svante Arrhenius hypothesized that a lifeless Earth was seeded with life-forms from outer space. Unlike Rael, however, he did not think that all creatures originated from clever extraterrestrial genetic engineers. Arrhenius’s life-forms were simply bacterial spores that drifted through space, landed by chance on Earth, germinated, and started the process of evolution. Arrhenius called this the concept of panspermia, suggesting that maybe life originated somewhere in our galaxy and then became distributed through it. This was an interesting idea, and it solved the problem of the origin of life on Earth. As expected, that idea was criticized from several angles. Granted, spores are hardened, dehydrated, dormant cells formed by some prokaryotic species. They are more resistant to heat, cold, and radiation than dividing cells. Spores are known to be the hardiest forms of life on Earth and some have been revived after spending 100,000 years in their dormant state. A somewhat controversial report even claims that 25to 40-million-year-old spores have been revived in the laboratory. Spores contain a unique enzyme that can repair ultraviolet (UV)-damaged DNA very efficiently, they are resistant to temperatures up to 150°C, and they can withstand pressures as high as 6000 atmospheres and as low as 10 11 atmosphere. They are also quite resistant to gamma radiation. However, are they hard enough to have resisted conditions prevalent in outer space? Assuming bacterial spores were ejected into space by gigantic volcanic eruptions or asteroidal impacts on a solar or on an extrasolar planet, which is possible, it would have taken them perhaps millions of years, depending on the distance between another solar planet and Earth or between their star and the Sun, to reach our planet. Meanwhile, the spores, even if hidden in the midst of dust grains or chunks of rock, would have been exposed to hard cosmic and ultraviolet rays that pervaded interstellar space. How long could they have resisted? Experiments conducted in the laboratory on Earth and aboard spacecraft, mostly with the spores of the soil bacterium Bacillus subtilis, show that panspermia within the solar system and even interstellar panspermia are valid concepts. As we have seen, laboratory experiments have demonstrated the high tolerance of bacterial spores to injuries inflicted by temperature, radiation, and extremes of pressure. Basically, panspermia is possible only if (a) spores can be ejected from another planet and resist the acceleration and heat produced in the escape process, (b) spores can tolerate space travel for perhaps long periods of time, and (c) spores can survive the reentry process into Earth’s atmosphere.

The escape process must have involved accelerations in excess of the host planet’s gravity. Laboratory experiments have shown that spores can tolerate up to 460,000 × g of acceleration, which is plenty to reach escape velocity from terrestrial types of planets. Then, spores must have been able to survive the hostile environment of space during their travel, during which they would have been exposed to stellar protons, electrons, alpha particles, cosmic rays composed of heavy ions, UV radiation, and X rays. They would also have experienced the effects of a high vacuum and extremes of temperature. Several satellite-based experiments have shed a considerable amount of light on the hardiness of spores in outer space. These experiments were conducted by the National Aeronautics and Space Administration (NASA) on Spacelab, the Long Duration Exposure Facility, and Apollo missions 16 and 17; by the European Space Agency aboard the European Retrievable Carrier; and by the Russian Foton spacecraft. The experiments demonstrated that 30 to 80 percent of B. subtilis spores survived 6 years of exposure to vacuum and radiation in outer space near Earth if they were embedded in crystals of glucose or salt, imitating meteoritic rock. Only a thin layer of this material was needed to completely shield the spores from UV radiation. Experiments conducted outside the Van Allen belts— which deflect charged particles, including most cosmic rays, from Earth— have shown that protection from cosmic rays is more challenging. Even so, it has been calculated that some spores would survive up to 25 million years in deep space if shielded by 2 to 3 meters of meteoritic material. The notion of spores embedded in meteorites naturally raises the question of whether bacteria can live in rock. The answer to that question is yes, as living bacteria have been found in boreholes as deep as 2.5 km inside Earth’s crust.

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The Search for Extraterrestrial Intelligence - Inspired by Religious Faith?

While science and religion are seen to be two opposing poles of a stick, never fated to meet, it seems the most ardent of tasks was inspired by religious faith after all, the search for extraterrestrial intelligence. The question that remains is, will you find the average Joe of an alien a church regular? Do you expect alien civilizations to be obsessed and compulsively driven by religion as humans?

Some scientists acknowledge the religious impulse that inspired their study of alien life. Carl Sagan was not among them. Although he was reluctant to accept religious interpretations of SETI research, Sagan used religious explanations to challenge the validity of UFOs. In an essay he contributed to the Encyclopedia Americana, Sagan argued that unidentified flying objects had less to do with scientific curiosity than with unfulfilled religious needs. For some people, he wrote, flying saucers “replace the gods that science has deposed.” When novelist Cynthia Ozick interviewed Sagan for a popular magazine, she noted the religious overtones of Sagan’s extraterrestrials. She said, “What you postulate is Angels. Faith, the same old faith.” Sagan retorted, “Not faith. Calculation. Extrapolation.” 2 Nevertheless, Sagan’s eldest son, Dorion, supported Ozick’s conclusions. Dorion, a science writer, scoffed at the search for extraterrestrial intelligence. He said it was nothing more than a replacement for religion in a secular age. Meanwhile, Sagan’s colleague Frank Drake readily admitted that a fundamentalist religious upbringing was the initial inspiration for him and others to join the search for advanced alien life. Granted, Drake repudiated his religious training in his youth. Nevertheless, in his mature years, he claimed that the extraterrestrials are virtually immortal and perhaps willing to pass on the secret of immortality to humans. When depicting the life and culture of intelligent aliens, anthropomorphic thinking enters to fill in the missing details. Extraterrestrials, we learn, are remarkably like us. They study mathematics and science, practice technology, and grapple with issues raised by warfare, environmental pollution, diminishing natural resources, disease, overpopulation, and energy crises. This blatantly anthropomorphic portrayal of alien culture is accompanied by the disclaimer that aliens are biologically different from humans.

Anthropomorphic thinking, however, lies close to the surface of speculation about extraterrestrial intelligence. SETI pioneer Frank Drake was once asked what form an intelligent alien might assume. He answered:

"They won’t be too much different from us. What I usually say, when people ask me that question, is that a large fraction will have such an anatomy that if you saw them from a distance of a hundred yards in the twilight you might think they were human."

Drake continued his description by noting that it was advantageous to walk upright on two legs with your head on top, eyes near the brain, and mouth near the eyes. He clearly believed that human anatomy serves as a pattern for intelligent aliens. Well, old Gorn on the left won't complain! When Drake was asked if aliens were real, he candidly responded: “You talk about something enough times, you begin to believe it. And we sure talk about this a lot.” Since the seventeenth century, philosophers and scientists have understood that anthropomorphic thinking exists in science. That is why scientists differentiate fact from value, resist granting humans a unique status in the universe, and avoid searching for purpose in the cosmos. Scientists claim they can produce objective knowledge even though their work rests upon human perception and understanding of the physical world. Sagan had his own solution to the problems introduced by anthropomorphism. He asked scientists to reject the chauvinisms that marred their thinking. A chauvinism is simpler to overcome than entrenched anthropomorphic thought because the former is easier to recognize and vulnerable to rational argument.

The main chauvinism that threatens the study of extraterrestrial organisms is the widespread belief that life must have the same physical basis everywhere in the universe. Sagan identified oxygen, carbon, ultraviolet light, and temperature chauvinisms. Each of these rests upon the false assumption that terrestrial and alien life have identical chemical and physical requirements.


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Thursday, June 24, 2010

Gods of the Final Frontier: Did Aliens Beat us to HyperSpace?



"My ideas caused people to reexamine Newtonian physics. It is inevitable that my own ideas will be reexamined and supplanted. If they are not, there will have been a gross failure somewhere." 
A. Einstein

Despite the efforts of SETI scientists to avoid the pitfalls of anthropomorphism, they duplicate terrestrial life and civilization on distant planets, creating a succession of alien worlds that mirror their own. SETI investigators tend to attribute terrestrial life and culture to the rest of the universe because they operate beyond the limits of their knowledge and competence when they discuss the universality of science and mathematics, biological and cultural evolution, the idea of progress, the nature of technology, and the meaning of civilization. Astronomers and physicists first meet these complex areas of knowledge when they venture into history, philosophy, and the biological and social sciences. Not surprisingly, they use concepts drawn from the physical sciences to determine the nature of alien cultures. Searchers for extraterrestrial intelligence suppose that alien mathematics and science are essentially like ours. When physicist Edward Purcell wrote about communication with extraterrestrials in the 1960s, he asked rhetorically: “What can we talk about with our remote friends?” His immediate answer was: “We have a lot in common. We have mathematics in common, and physics, and astronomy. . . . We have chemistry in common, inorganic chemistry, that is.” 2 Purcell not only assumed that the physical sciences are practiced throughout the universe but that alien science is bound to harmonize with terrestrial science. These premises, crucial to the belief that we can communicate with advanced extraterrestrial civilizations, are riddled with philosophical difficulties.

The Cosmic Buzz Killers - Distance & Speed

All available evidence indicates that the speed of light is the absolute fastest anything can go, like...ever. Engineers think nothing like warp drive is possible under the rules of nature. Reaching even a fraction of light speed would be very difficult. Also travelling really fast is dangerous! At 700 million miles per hour, hitting even a grain of cosmic sand would release the explosive power of an atomic bomb. The distances between stars is enormous, so enormous that they're hard to wrap your head around. Zip through at speed of light and  it will cost you 4 years of your life, try to reach the far side of the milkyway's spiral arm and be ready for a solitary confinement of a 100,000 years. If, you take the Drake's equation at face value, even at a galactic density of a million star systems with intelligent life, the average distance between civilizations would be over 500 light years.  Why wrestle with all the hassle when the job can be done without breaking a sweat, cosmologically speaking. 


Enter ........... HyperSpace


Hyperspace exists in layers, both above and below the normal space. Objects in hyperspace travel in constant speeds, that is their speeds are multiples of the speed of light. "An object moving through hyperspace is subject to a phenomenon akin to a frictional force that is proportional to both its size and its mass. Because the object's speed cannot change in hyperspace, it must expend energy in order to continue moving, as though it were working against friction. If the object stops expending energy or does not expend enough energy, it simply drops out of hyperspace and back into normal space." Once you're in hyperspace, enormous distances  lose their meaning altogether, millions of years worth of travel can be transcended in mere moments.  
The upside of being a hyper-space dweller is that you have the luxury of existing in multidimensional time streams. These beings can exist on earth, hyperspace and in higher dimensional universes simultaneously. All different experiences contributing towards one complete instance of life!


BREAKING NEWS: The engineers at the Department of Energy have already started developing a prototype, believe it or not, to break the light-speed barrier. The prime requirement is the generation of an ultra powerful magnetic field to push the space vehicle - dubbed the Z-machine, in to another dimension. A working prototype engine is expected to be presented for testing in 5 years. So hold on to your lose change, you might need it to buy the first tour packages to the red planet.  


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Tuesday, June 22, 2010

Not Only is the Space Black, Its also Silent - Where are the Aliens?

Not only is space black, it is also silent. Surrounded by endless stellar reaches, Earth seems a lonely outpost devoid of communications from any other world. Given the likelihood of planetary systems orbiting many (if not most) of the stars we see, why hasn’t a single one of them sent us a simple hello? Could space be as empty of life as it is of light, or might there be another explanation?
The great Italian physicist Enrico Fermi pondered this dilemma in 1950 while taking a break from the rigors of Los Alamos Laboratory. It was the era of the UFO craze, and newspapers were brimming with speculations about the prospects for alien visitors. A clever cartoon about the subject caught his eye and led him to estimate the probability of extraterrestrial contact. During a casual lunch, he raised the topic with three of his colleagues— Edward Teller, Herbert York, and Emil Konopinski. While discussing sundry matters, Fermi suddenly asked, “Where is everybody?”

The “everybody” in question referred to the preponderance of extraterrestrials our vast universe ought to contain. As Fermi pointed out, given a sufficient number of worlds in space, at least a fraction of them should harbor civilizations advanced enough to attempt contact with us. Then, considering that the cosmos has been around for billions of years, why haven’t any of them sent signals by now? The curious situation that Earth has never encountered alien communications has come to be known as Fermi’s paradox. Drake and Sagan were leading proponents of the Search for Extraterrestrial Intelligence (SETI), a systematic hunt for radio signals from alien civilizations. Beginning in the 1960s, radio dishes around the world have scanned the skies for telltale coded patterns. In the intervening decades the SETI program has been greatly expanded, encompassing a wider range of frequencies and a broader array of targets. Improved software and faster processing rates have made it easier to wade through the haystack of radio noise, thereby enhancing the prospects for uncovering buried messages. Alas, despite a number of false alarms, not one has been found.

BEYOND THE COSMIC HORIZON

Even if advanced life is rare in the Milky Way, that does not preclude an abundance of civilizations in other galaxies. An infinite universe would render even the slimmest chance for intelligence a reality somewhere else in space. Given enough room in the cosmos and enough time for intelligence to develop, the cosmic roulette wheel would be bound to hit the lucky number. It would be just like placing a million monkeys in front of a million computers and letting them bang on the keyboards for an extremely long time. Eventually, through their random actions, one of them would type a Shakespearian sonnet. The lower the probability for intelligent life to evolve, the farther we need to look to find it. Hence, before drawing conclusions about the current failure of the SETI mission to discern signals from within the Milky Way, we must expand our search to include other galaxies. Although the present-day program envisions civilizations with the capacity to broadcast messages over tens or hundreds of light-years, we can easily imagine extragalactic cultures with even greater capabilities. Moreover, because each galaxy potentially harbors hundreds of billions of worlds, there could very well be far more civilizations able to reach us with their signals outside the Milky Way than within it. Therefore, by aiming our radio dishes at intergalactic as well as intragalactic targets we might improve our search for extraterrestrial intelligence.

Well, this is it for now folks. For blokes up in the North West, hope you didn't miss the blazin' comet last fortnight. Stay tuned for my next post on the Beauty of Quantum Mechanics and Whether Alien Civilizations have already beat us to Hyperspace, the final frontier.

P.S: To enthusiastic readers, if you have any information on any upcoming meteor showers or Comet passby's near the Equator or the Tropic of Capricorn, do let me know. The astronomical society down here isn't too big on fabulous cosmic events. Leave some comments and I'll get back to you!

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