What if extraterrestrial beings looked like us

Signals from extraterrestrials in the genetic code? : "We are looking for relics of superior intelligence"

In their search for extraterrestrial civilizations, researchers have compiled almost two petabytes of observation data about the Milky Way - now the privately funded initiative “Breakthrough Listen” has made the data publicly available, as has the University of California, which is involved in the search for extraterrestrial intelligence (SETI) Berkeley announced. Some of the data can even be analyzed on home PCs via the University of California's SETI @ Home citizen research network.

"This is the largest publication of SETI data in history," said "Breakthrough List" chief scientist Andrew Siemion of the University of California. The data comes mainly from the Parkes radio telescope in Australia and the Green Bank radio telescope in the USA. For the past four years they had been listening 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 a research group since 2005 that is working on how to react if one should actually come across signals from aliens in the huge amounts of data from SETI. But perhaps the time-consuming search in the vastness of space is not even necessary. Because in an interview with Tagesspiegel, Davies thinks it is possible that aliens could have long since left traces of their existence on earth - for example in the human genome.

Mr. Davies, if you are looking for life on strange planets, you first have to know how to recognize it. Don't we know?

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 collection of molecules into a living being? A clearer definition of life could help us a lot.

What else is there?

Most of the research on the origin of life over the past hundred years has focused on biochemistry, on whether it is possible to recreate the building blocks - such as amino acids for proteins or nucleic acids for the genome - and bring them to life by supplying energy. I always had doubts about this approach. For two reasons: On the one hand, it assumes that if you know how to make a brick, you can also build a city. But I believe that this is a lot more difficult. Second, life is not just based on hardware - that is, the basic building blocks, the molecules that we are made of. It also needs software - that is, organized information. Otherwise it would be as if we were only explaining the amazing things that computers can do by saying that they are made of silicon, copper and plastic and that electricity flows through them. The real secret lies elsewhere, in the software.

So organized information is also part of life?
Correct. Our genetic make-up is full of coded information, which will not lead to anything if it is not decoded again. To do this, evolution has developed a complex machine: 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, which give each other chemical and physical signals. Or the flow of information between animals, which leads to amazing achievements in ant colonies, for example: Although each individual animal is pretty stupid, the state often makes very clever decisions as a collective. Actually, the entire biosphere represents a huge network with exchange of information that defines this planet. It is the real World Wide Web. The decisive question now is how the first coded information of life came about. Are there any fundamental laws that govern this? If we found such laws, and they make the emergence of life in Earth-like conditions probable, SETI, i.e. the search for aliens, would experience an enormous boost.

A boost that would be expected from a microbial discovery on Mars?
Yes, both would be strong indications that life in space has arisen multiple times and has possibly evolved into intelligent beings. We know that there are many Earth-like planets out there. But we do not know whether this great step inevitably takes place under such circumstances, or whether it was such a great 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 bigger than the first step ...
This second big step took longer in the history of the earth. 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. It is therefore particularly important to understand the first step. I believe we'll 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 be certain whether life can be found there, will take place in the late 2030s at the earliest.

Do you already have ideas of 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 higher complexity than fixed laws, such as the well-known physical laws. The natural constants, for example, that apply everywhere and for everything.

What would such a dynamic law look like?
Imagine a game of chess in which the rules change with a certain constellation. For example, when a player has two pawns less than the other, he can move them both back and forth instead of just forward. This would result in completely new game situations that would be impossible in normal play. Something along the way could happen to living systems as well. The exchange of information in the genome only takes place under certain circumstances and is systemically linked to other factors. DNA by itself is just a series of letters that mean nothing.

How are you going to find out about these laws?
That's the advantage: We don't need any 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 work together on the molecular level. A new field of research is currently opening up there. We already know the nanotechnological methods required for this. Therefore, several researchers around the world are already looking.

Will this change the search for aliens?
It is unclear. If so, then above all the search for animate planets changes in general. It is possible that the previous analysis of the biochemical signals in the light of planets can be narrowed down to certain patterns by finding such laws. But even that is only a vague guess. Independent of this, SETI has already changed: For a long time, people were primarily looking for targeted messages from aliens. But in order to recognize whether we are alone in the universe, one does not need such a thing. Especially since that is extremely unlikely. Because it can be assumed that ET will only call us when he knows that we can also receive it. We have only been using this technology for a good hundred years. So ET would only report this way if it was within 50 light years. From an astronomical point of view, this still belongs to the immediate vicinity and is therefore hardly conceivable. Instead, today we are more likely to look for relics of superior intelligences in our cosmic environment.

The aliens came by in the past and left something behind? Sounds like the theories of Erich von Däniken, a well-known Swiss ufologist ...
I'm not saying they did that. But it could be. You know: I actually don't believe that there actually is any other intelligent life in space. But I'm open to it, an open-minded skeptic so to speak. I see what fascination the idea exerts on people; it makes many young people interested in astronomy and biology. And it causes us to think about how we see ourselves as humanity. That alone makes this research useful.

Where could such relics be found?
Personally, I prefer search methods that do not cost us anything. For example, it would be conceivable to find some extraterrestrial artifact on the moon. We are currently mapping it in high resolution as part of other projects. So why not make these images available to everyone and look for suspicious clues in school projects, for example? The probability of finding something is extremely small. But it doesn't cost us anything and it's fun. I also find the idea of ​​the genomic SETI interesting: a superior intelligence could have left us a message in our genome - a conspicuous sequence of letters that correspond to prime numbers, for example. The American biochemist Craig Venter has proven that something like this works: he built his e-mail address into a genome. Since we're sequencing the genes anyway, we could check this in one go.

That sounds really crazy ...
But it would be conceivable. And it's no crazier than the idea that aliens could have targeted us on the radio. Perhaps, if we discover the secret of life, we will soon know better whether and how we should look.

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