“Are we alone in the universe?” The cliché start of the first astrobiology articles of rookie science writers is no longer in vogue these days. With almost daily announcement of the discovery of new exoplanets and calculations of astronomers which put the number of potentially habitable planets in the Milky Way alone at tens of billions, the question now rather is “where are they”. That the curiosity has ceased to be the obsession of a few astronomers is evident from millions of home computers volunteered for the analysis of terabytes of data compiled by SETI (Search for Extraterrestrial Intelligence) project which is listening to the elusive voice of ET with a wide open ear: The 300-meter Arecibo radio telescope in Puerto Rico.
There’s no harm in listening for signals announcing the presence of advanced extraterrestrials around. After all, we’ve been doing that for some 50 years. Besides browsing through radio wavelengths, or looking for high-energy laser pulses, alternative proposals are in no short supply in the realm of “passive” searches. Some of these, evidently products of stretched imaginations, appear based on the supercivilization classification of Russian astrophysicist Nikolai Kardashev.
To name but a few, looking for conspicuous gaps in galactic niches for “Dyson spheres” encasing stars – and thereby making it invisible –an advanced civilization might have built to exploit all of its energy, or distinctive gamma rays emanating from atomic size “black hole engines” manufactured to provide propulsion for space faring races. Some say look for oddly -shaped (e.g. pyramidal ) planets transiting the face of their stars. Still other alien markers are identified as mined-out asteroids around stars or debris such as machinery or engineered items thrown overboard by less civilized envoys of supercivilisations traversing our Solar system.
But when it comes to changing tactics in a bid to “attract” the attention of intelligent aliens, the prevailing sentiment is ranging from cool reception , to vocal opposition. A poll, conducted by a Spanish university psychologist showed that humans were not ready to try contacting an extraterrestrial civilization, while a renowned physicist thumbs down the project as outright suicidal. Nevertheless, “contact” diehards keep transmitting our whereabouts, sometimes with innovative methods.
Kardashev Scale If SETI intercepts a signal which defies a natural explanation, you can expect the eyebrows to be raised. It has to be coming from an advanced extraterrestrial civilisation. But how advanced? Russian (at the time, Soviet) astrophysicist Nikolai Kardashev gave us a yardstick. The 82-year-old scientist published a seminal paper in 1964, in which he divided advanced civilisations into three categories based on the level of energy they are able to utilise which acquired fame as the “Kardashev Scale.” On the first rung stands the Type I civilization, which is able to utilise all the energy of its planet.
This calls for the extensive application of fusion power through conversion of hydrogen to helium, making use of about 130 quadrillion tons of hydrogen contained in Earth’s oceans which can get its civilisation going for billions of years, to be supplemented with renewable energies, including the harnessing of the Sun’s energy through solar cells or concentrators, as well as wind and hydroelectrical power. To be promoted to the Type II civilization requires, as starters, to scale up these feats to large numbers of planets in large numbers of solar systems. But a supercivilization worth its salt should be able to construct megastructures called “Dyson spheres” (envisioned by physicist Freeman Dyson) surrounding a star to absorb all of its energy, or at least “Dyson swarms” of power satellites or space habitats around a star.
More advanced civilisations of this type could hypothetically tap into the power of black holes by feeding stars to them, or strip a star of its material for alternative uses, exploit antimatter which would be available as an industrial byproduct, could harness the energy spewed out by the hypothetical “white holes” – at the other ends of black holes – or capture the energy of gamma ray bursts, the most violent events in the universe. Sitting on top of Kardashev’s scale is the Type III civilization which proves its superiority by harnessing the total power output of a whole galaxy or several galaxies, by individually employing the methods of Type II civilisations for all the stars, and maybe also by tapping into the power of supermassive black holes believed to be a the centers of most galaxies.
The Kardashev scale was extended by others in later years to even higher categories, with Type IV civilizations credited with the ability to harness the energy of the entire universe, and Type V , using the energy of a collection of universes. Although Kardashev has been considerate enough to overlook the technological level we have attained, others saw no scruples in unceremoniously delegating us into a “Type 0” category , since our fossil fuel-based technology is still far away from making use of everything our planet has to offer.
Apparently thinking that recent findings which imply the existence of tens of billions of potentially habitable planets in the Milky Way and the discovery of earth-alikes in rapid succession make a visit by the spacefaring alien inevitable, neuro-psychologist Gabriel G. de la Torre of Spain’s Cádiz University wondered what the reaction would be.
[Text Box: Artist’s conception of a Dyson swarm around a star. The alternative Dyson sphere was envisaged to be a solid bubble sucking up the star’s total energy utilised by a Type II civilization on the bubble’s surface.] Choosing to go after informed opinion, he had 116 Spanish, Italian and American university students to fill an extensive questionnaire to measure the pick of humanity’s degree of readiness to meet the alien with the wanderlust. The participants were rated on their knowledge of astronomy, the place of things in the cosmos, the level of their perception of the environment, their views about the likelihood of contact with the extraterrestrials and the depth of their religious convictions.
The findings, sadly, are not likely to fill “look, we’re here” activists with renewed zest: "… the knowledge of the general public of a certain education level about the cosmos and our place within it is still poor. Therefore, a cosmic awareness must be further promoted – where our mind is increasingly conscious of the global reality that surrounds us – using the best tool available to us: education," De la Torre concludes. University students – and by inference, the rest of the society – were found wanting in many aspects of astronomy despite great progress in science and technology. They appeared viewing the cosmic events through the window of religious beliefs and relying on politicians to solve crises of global import.
"Regarding our relation with a possible intelligent extraterrestrial life, we should not rely on moral reference points of thought, since they are heavily influenced by religion. Why should some more intelligent beings be 'good'?," muses the researcher. On the other hand, he objects to the business of search for extraterrestrial being monopolized by a handful of scientists. Contacting the extraterrestrial – with unfathomable motives – is a matter in which all humanity should have a say, “after a proper education on these matters”, a cautious De la Torre concludes.
Another advocate of prudence is no other than famed physicist Stephen Hawking ,who has warned before that even the well –meaning aliens may come with unwanted gifts in the form of infections against which we have no defense.
More recently, however, the scientist known for his witty style besides his theories on black holes and universe in general, has remarked that intelligent extraterrestrials could not be counted on for good intent – taking his cue from a familiar species: "We only have to look at ourselves to see how intelligent life might develop into something we wouldn’t want to meet," he said in the 2010 debut of the TV documentary “Into the Universe with Stephen Hawking.” "I imagine they might exist in massive ships … having used up all the resources from their home planet. Such advanced aliens would perhaps become nomads, looking to conquer and colonize whatever planets they can reach.”
In a more ominous note, he contemplated that a visit to Earth might well be like the arrival of Christopher Columbus in the New World, “which didn’t turn out very well for the Native Americans.”
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Earliest Earthly television broadcasts have now passed 10.000 stars by that account, speculates Dan Werthimer, a leading ET hunter with SETI, who was addressing a Congressional committee in a bid to secure more funds for the decades-long endeavour. “The nearby stars have seen ‘The Simpsons.’ If we’re broadcasting, maybe other civilizations are sending signals in our direction – either leaking signals the way we unintentionally send off signals, or maybe a deliberate signal.”
[Text Box: The Pioneer plaque (above) and the (false color) Arecibo message (right).] As for our own deliberates, the earliest message to the exraterrestrials, drawn up by the late astronomer Carl Sagan and Frank Drake, the author of the famous equation about the probability of intelligent life in the universe, were sent out in 1972 and 1973, respectively, with Pioneer 10 and Pioneer 11 spacecraft. The message was in the shape of identical metal plaques etched with figures of a man and woman, together with symbols showing our place in the Solar System and over a dozen pulsars to point the way. It also contained representations of the hydrogen atom and the flip of its electron’s spin which results in the emission of radio waves of a specific (21 cm) wavelength – which rings out throughout the universe as hydrogen is the most abundant element – which would supposedly show that our civilisation was at least as civilised as to know the fact. Interestingly, this first message to the extraterrestrials was the only one which an ordinary human would be able understand, although subsequently it came under criticism for looking addressed to human perception instead of the alien.
Since then, the more loosely connected constellation of messaging-the-alien groups under the fold of Active SETI, or METI (Messaging to Extra-Terrestrial Intelligence) as coined by the famed Russian radio astronomer and avid alien-hunter Aleksandr Zaitsev, has made several attempts to contact the putative extraterrestrial civilizations . These include consecutive Cosmic Calls transmitted from the Yevpatoria Planetary Radar in Crimea. Another Zaitsev organised call, The Teenage Message to ETI (Extra-Terrestrial Intelligence,), not surprisingly, included a recording of electronic music, and later a “Beatles” recording beamed by NASA, both arguably a better medium of communication than all those elaborately concocted messages in “computerese”.
The Pioneer plaque (above) and the (false color) Arecibo message (right).
These show a digitalised human figure – the only recognizable symbol – amid lines and lines of differently configured clusters of squares on a grid whose meanings were made known to baffled Earthlings by experts with extensive explanation in plain text. As for the aliens, they have to divine the meaning themselves.
[Text Box: • The Morse Message (1962) • Arecibo message (1974) • Cosmic Call 1 (1999) • Teen Age Message (2001) • Cosmic Call 2 (2003) • Across the Universe (2008) • A Message From Earth (2008) • Hello From Earth (2009) • RuBisCo Stars (2009) • Wow! Reply (2012) • Lone Signal (2013)] Messages were also sent in everyday language by the public, in expectations that it would be child’s play for ultra-advanced civilisations to dechipher the letters used by humans, the sounds they correspond to, the words they form and the meaning of these words written in different languages.
[Text Box: The 70-meter Yevpatoria RT-70 radio telescope or planetary radar at Crimea, one of the largest of its kind, has an advantage others lack, in that it is equipped with powerful transmitters that permit precision beaming of radio signals at distant stars potentially orbited by life-bearing planets.] In 2012, the Arecibo radio telescope transmitted 10.000 twitter messages in the direction of constellation Sagittarius, in “reply” to a a strong, but not repeated radio message dubbed the “Wow signal”. The signal, with a frequency almost identical to that of the hydrogen line, was intercepted 35 years earlier, during the 72 seconds that Ohio State University’s Big Ear radio telescope panned across the sky. Follow up searches failed to catch the signal again.
Meanwhile Jacob Haqq-Misra, a post-doc at Pennsylvania State University and the now-deceased businessman Pierre Fabre organised an initiative in 2013, The Lone Signal, calling space enthusiasts to beam Twitter-style, 144-character personal messages to a star they identified as Gliese 526, which, they said was a red dwarf star “possibly” having a solar system, 17.6 light years away in Constellation Boötes. The team hopes to raise some 100 million dollars through the scheme, to be spent on the establishment of a network of dishes across the world. The signals, beamed via a recommissioned radio telescope called Jamesburg Earth Station in Carmel, California, will reach their target in 2031.
The 70-meter Yevpatoria RT-70 radio telescope or planetary radar at Crimea, one of the largest of its kind, has an advantage others lack, in that it is equipped with powerful transmitters that permit precision beaming of radio signals at distant stars potentially orbited by life-bearing planets.
Provided there is a planet around the target star, inhabited by linguistics-savvy extraterrestrials who decipher the messages and reply immediately, earliest messagers will have to wait until 2048 to check their mailboxes. A prominent endorser of the project was futurist Ray Kurzweil, who foresees artificial intelligence surpassing that of humans in a few decades, after which the humans, ceasing to be purely biological and to be vastly augmented by artificial intelligence and products of nanotechnology, would rule the universe. In style, the computer scientist informed the putative addressee, that by the time his message arrives, the human race will be much smarter thanks to computers.
Then, perhaps, responses of future participants in new polls about mingling with extraterrestrials would not be as troubling as what the Cádiz neuro-scientist.
REFERENCES
- 1. “Are we ready for contact with extraterrestrial intelligence?”, FECYT - Spanish Foundation for Science and Technology, 6 May 2006
- 2. “Hawking: Aliens may pose risk to Earth”, The Daily Telegraph, 25 April 2010
- 3. “Active SETI”,Wikipedia, http://en.wikipedia.org/wiki/Active_SETI
- 4. “Alien Life Discovery Could Happen Within 20 Years”, Discovery News, 22 May 2014, http://news.discovery.com/space/alien-life-exoplanets/alien-life-discovery-could-happen-within-20-years-140521.htm#mkcpgn=emnws1