In 1960, astronomer Francis Drake pointed a radio telescope at Green Bank, West Virginia, at two sun-like stars 11 light-years from Earth. He hoped to pick up a signal that would indicate the existence of intelligent life.
It's been 50 years since Drake's pioneering experiment, and we still haven't heard anything about extraterrestrial life. However, thanks to a host of discoveries, the idea that life could exist outside of Earth seems more plausible than ever.
We learned that life can thrive in some of the most extreme conditions on Earth - in the depths of the sea near methane sources, in the Antarctic ice and in the driest deserts.
We also found out that liquid water is not a unique feature of our planet. Saturn's moon Enceladus and Jupiter's moons Ganymede and Europa also have oceans hidden by the icy surface. Even Saturn's largest moon, Titan, can store some life in its methane-ethane lakes and rivers.
And along with the discovery of exoplanets, we know that there are at least 1,800 worlds outside the solar system that are worth exploring. Essentially, astronomers speculate that there may be a trillion planets in a galaxy alone, a fifth of which may be Earth-like. Carl Sagan once said, “The universe is a pretty big place. If it is only ours, then a lot of space is wasted."
- Today, some scientists believe that the hunt for life outside the Earth can bear fruit in our generation. “There were 10,000 generations of people before us. Ours will be the first to know [the truth],”said SETI astronomer Seth Shostak.
But what will happen when we find out? How do we transfer this discovery? What will be its impact on society? This sensitive issue was the focus of a conference organized in September by NASA's Astrobiology Institute and the Library of Congress.
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Over the course of two days, a group of scientists, historians, philosophers and theologians from all over the world discussed how to prepare the world for the inevitable discovery of another life - microbial or intelligent - somewhere in the universe. The symposium was hosted by Stephen Dick.
Of course, the impact of the discovery will depend on the specific situation. In his speech “Modern Approaches to the Search for Life Beyond the Earth, and What Happens if We Find It,” Shostak described three paths - or three horse races - of finding life in space. First, we can find it nearby - in our solar system.
NASA's Curiosity rover is currently exploring the surface of Mars in search of signs of life past or present. Europa Clipper, a mission to Jupiter's icy moon, is also under discussion at the moment. Second, we could sniff out life in exoplanet atmospheres using a telescope to look at gases, methane or oxygen, which could be a good signature. The James Webb Space Telescope, which will launch in 2018, could do just that.
The discovery of life in our solar system, which is likely to be microbial, may not have such a serious impact on us as some intelligent civilization from afar. We will worry about the possibility of contamination. Perhaps we will even discover alternative biochemistry, discover new secrets about the nature of life. But this discovery will definitely not affect us in the way that the discovery of intelligent aliens could.
And again, it will take hundreds, if not thousands of years for the signal to get there and back. The third scenario tells us very little, except what the location of life and around what type of star its planet revolves.
Some researchers, including Shostak, make the following assumption: "Once a society creates the technology that can put it into space, it is several hundred years from a complete paradigm shift from biology to artificial intelligence." This idea is based on the so-called "timescale argument".
Many scientists speculate that we will develop artificial intelligence by 2050 here on Earth - just a hundred years after the invention of computers, or one hundred and fifty years after the invention of radio communications. “The point is that the transition from radio to intelligent machines will not take long - a couple of centuries at the most,” Shostak says. "The dominant intelligence in space may well be non-biological."
Susan Schneider, a professor of philosophy at the University of Connecticut, takes this idea even further in a speech on “Alien Minds”. The concept of "full brain emulation" is becoming more and more popular among certain scientists. This is where other interesting ideas grow, such as "uploading consciousness" and "immortality." According to her, a civilization that can communicate using radio communications will be "superintelligent" by the time we catch its signal.
It is believed that a civilization capable of maintaining radio communication should develop artificial intelligence by the time we contact it. Susan argues that extraterrestrial superintelligent life will be conscious in principle, since the neural code will be akin to the computational one and, therefore, will fit well on a silicon substrate.
Silicon-based intelligence would also be extremely good for long-term space travel. But again, scientists are moving more into anthropocentric tendencies. There is a huge gap between microbial and intelligent life on Earth, and there is no guarantee that other intelligent life will develop in the same way.
Lori Marino, neuroscientist and director of the Kimela Center for Animal Advocacy, gave a speech on "Landscape of the Mind." We have a lot to learn from other sentient beings on Earth (such as dolphins) before thinking about contact with aliens.
Ultimately, the biggest implications will be philosophical. The emergence of microbial, complex, or intelligent life anywhere other than Earth raises interesting questions about our place in space. Theologians believe that this will seriously hit the religions of the planet. But what if we don't find anything soon, or never at all?
The search itself can give us a sense of direction and help us shape a planetary identity, says philosopher Clement Vidal. If we are truly alone, we should take better care of life here on Earth, while developing colonies in parallel. At the same time, astrobiology can help us narrow the gap between the natural sciences and the humanities.
How do we prepare to face what we know so little about? We do by “continuing to make good science, but not losing sight of the fact that science is not a panacea,” Steven Dick summed up the conference. "We prepare by continuing to ask questions about the nature of life and mind."