In the search for extraterrestrial civilizations, researchers have gathered almost two petabytes of observational data on the Milky Way – now the privately funded Breakthrough Listen initiative has made the data resource publicly available, such as that involved in the search for extraterrestrial intelligence (SETI) University of California at Berkeley announced. Some of the data can even be analyzed on home PCs through the University of California's SETI @ Home citizen research network.
“This is the largest release of SETI data in history,” emphasized Breakthrough Lists Chief Scientist Andrew Siemion from the University of California. The data comes primarily from the Parkes radio telescope in Australia and the Green Bank radio telescope in the USA. In the past four years, they had listened to the star-populated disk of the Milky Way for possible radio signals from extraterrestrial civilizations.
The astrophysicist Paul Davies from Arizona State University has been leading 2005 a research group that develops how to react if one should actually come across signals from extraterrestrials in the huge amount of data from SETI. But maybe the time-consuming search in the vastness of space is not necessary at all. In an interview with Tagesspiegel, Davies believes it is possible that aliens may have left traces of their existence on Earth long ago – for example in the human genome.
Mr. Davies, if you are looking for life on foreign planets, you first have to know how to recognize it. Don't we know that?
The great unknown in the search for extraterrestrial life is its original origin, the transition from the dead to the living. What is the spark that turns a cluster of molecules into a living being? A clearer definition of life could help us a lot.
What's wrong with that?
Die Most research in the past hundred years on the origin of life has focused on biochemistry, on whether it is possible to reconstruct the building blocks – such as amino acids for proteins or nucleic acids for the genome – and bring them to life by supplying energy. I have always had doubts about this approach. For two reasons: First, it assumes that if you know how to make a brick, you can also build a city. However, I believe that this is much more difficult. Secondly, life is not just based on hardware – the basic building blocks, the molecules that make up us. You also need software – organized information. Otherwise it would be like explaining the astonishing things that computers can do only by the fact that they are made of silicon, copper and plastic and are traversed by electricity. The real secret lies somewhere else, in the software.
So life also includes organized information?
Right. Our genome is full of encoded information, which, however, leads to nothing if it is not decoded again. Evolution has developed a complex machinery for this: genes that switch each other on and off, and so on. Many researchers are busy deciphering these networks and their functions. On the genetic level as well as on the level of the cells that give each other chemical and physical signals. Or the flow of information among animals, which leads to astonishing achievements in ant states, for example: although every single animal is quite stupid, the state often makes very clever decisions collectively. The entire biosphere is actually a huge network of information exchange that makes up this planet. It is the actual World Wide Web. The crucial question now is how the first coded information of life came about. Are there any basic laws that govern this? If we found such laws and they made life in Earth-like conditions probable, SETI, i.e. the search for extraterrestrials, would experience an enormous boost.
A surge as would be expected from the discovery of microbes on Mars?
Yes, both would be strong indications that life in space has arisen several times and may have developed into intelligent beings. We know that there are many Earth-like planets out there. But we do not know whether this big step inevitably takes place under such circumstances, or whether it was such a coincidence on earth that it remains unique in the universe despite this vast number of worlds. Many researchers believe that the transition must have happened several times. But we just don't know.
Many say that the step from simple to complex, intelligent life is much larger than the first step …
This second big step took longer in the earth's history. Nevertheless, we already know the process behind it: evolution. What we don't know is the likelihood that this will lead to intelligence. But the step as such is no longer mysterious to us. That is why it is important to understand the first step. I think we will find the laws for this in the next ten years, before we track down extraterrestrial life. The first manned trip to Mars, from which many experts hope to find out whether life can be found there, will be at the earliest in the late 2030 years.
Do you already have ideas about what such a law could look like?
Our preliminary suggestion is that these new laws may depend on the state of matter. This leads to significantly greater complexity than fixed laws, as are the known physical laws. The natural constants, for example, that apply everywhere and for everything.
What would such a dynamic law look like?
Imagine a chess game in which the rules change with a certain constellation. For example, if a player, as soon as he has two pawns less than the other, is allowed to move them both forwards and backwards instead of just forwards. This would create completely new game situations that would be impossible in normal play. Something along these lines could also happen to living systems. The exchange of information in the genome only runs under certain circumstances and is systemically linked to other factors. The DNS itself is just a sequence of letters that means nothing.
How do you intend to find out about these laws?
This is the advantage: We do not need new giant telescopes or particle accelerators. If there are such laws, then we will probably find them through quantum mechanical experiments in nanotechnology, because quantum theory, chemistry and information theory only interact at the molecular level. A new research field is currently opening there. We already know the necessary nanotechnological methods. Therefore, several researchers worldwide are already looking.
Will this change the search for extraterrestrials?
This is unclear. If so, the search for busy planets in general changes. It is possible that the previous analysis of the biochemical signals in the light of planets can be limited to certain patterns by the discovery of such laws. But even that is just a vague guess. Regardless of this, SETI has already changed: For a long time, people were primarily looking for targeted messages from aliens. But to recognize whether we are alone in the universe, there is no need for one. Especially since this is extremely unlikely. Because it can be assumed that ET will only start us when it knows that we can also receive it. We have only been using this technology for a good hundred years. So ET would only report in this way if he was within 50 light years , From an astronomical point of view, this still belongs to the immediate neighborhood and is therefore hardly conceivable. Instead, today we are looking for relics of superior intelligence in our cosmic environment.
The aliens came by in the past and left something behind? Sounds like the theories of Erich von Dänikens, a well-known Swiss ufologist …
I'm not saying that they did that. But it could be. You know: Actually, I don't believe that there really is any other intelligent life in space. But I'm open to being an open-minded skeptic, so to speak. I see what fascination the idea has on people; it makes many young people interested in astronomy and biology. And it causes us to think about our self-image as humanity. That alone makes this research useful.
Where could such relics be found?
I personally prefer methods of search that do not cost us anything. For example, it would be conceivable to find some alien artifact on the moon. We are currently mapping it in high resolution as part of other projects. So why not make these pictures accessible to everyone and look for suspicious traces in school projects? The probability of finding something is extremely low. But it doesn't cost us anything and is fun. I also find the idea of the genomic SETI interesting: A superior intelligence could have left us a message in our genome – a striking sequence of letters that, for example, correspond to the prime numbers. The American biochemist Craig Venter has proven that this works: he has built his email address into a genome. Since we are sequencing the genes anyway, we could check this in one wash.
That sounds really crazy …
But it would be conceivable. And it's not crazier than the idea that extraterrestrials could have sent us a radio message. Maybe if we find out the secret of life, we will soon know better if and how we should search.