Interview: Ulrike Scheffer
In discourse
“Life is a cosmic imperative”
Astrophysicist and DAAD alumnus Professor Zaza Osmanov sees his work as cosmic archaeology: searching for technical traces of extraterrestrial civilisations in space. His conclusion is that we are not alone.
Issue 1 | 2026
Professor Osmanov, how did you come to devote yourself to searching for extraterrestrial life?
Zaza Osmanov: In my research I focus on black holes, neutron stars and cosmic radiation. This inevitably prompts one to question whether we are alone in the universe. We now know that life on Earth evolved at least 3.5 billion years ago – essentially as soon as our planet provided the necessary conditions for life. This suggests that life is a kind of cosmic imperative. The same laws of physics and chemistry apply throughout the universe, so if we find similar baseline conditions elsewhere, it is highly probable that biology will likewise evolve there.
Do you believe that other intelligent beings could exist in the universe?
Osmanov: The universe encompasses at least a trillion galaxies, and our galaxy alone has at least 100 billion stars, at least 30 percent of which are orbited by rocky planets similar to Earth. So why should we be the only ones to exist? Moreover, the stars in the Milky Way are millions of years older than our sun, meaning there could be significantly more advanced civilisations than ours. In research, we talk about Type II civilisations according to the so-called Kardashev Scale. We humans have currently reached a development level of roughly 0.75 on this scale and will probably need another thousand years to achieve Type I status.
Along with other astrophysicists, you search for “technosignatures” to prove the existence of extraterrestrial civilisations. What exactly does this mean?
Osmanov: Technosignatures are technical traces of other civilisations in the universe. Once it achieves a sufficient level of technological advancement, a civilisation will inevitably erect structures in space to meet its huge demand for energy. Even if the civilisation in question has long since ceased to exist, these structures will remain as artefacts – just like our disused satellites that continue to orbit the Earth as space debris. We use state-of-the-art telescopes and physical models to detect such technosignatures. You could imagine our work as a kind of cosmic archaeology.
What type of technical structures might highly developed civilisations erect in space?
Osmanov: The physicist Freeman Dyson once suggested that highly developed civilisations might build a structure to completely encompass their host star in order to harness all of its energy. However, a civilisation would have to destroy all the planets and asteroids in its solar system to obtain sufficient material to construct such a gigantic sphere. I think it’s more likely that they would use pulsars – extremely dense and rapidly rotating neutron stars. Pulsars have a radius of around ten kilometres and emit large amounts of energy. A Type II civilisation could build a ringlike structure around the pulsar to capture its energy. This would require only a fraction of the material, wouldn’t destroy the civilisation’s planetary system and would be far more energy-efficient.
So you are looking for the technosignatures of such “solar power systems”?
Osmanov: Yes, though there is also another way of proving the existence of other civilisations: according to the laws of thermodynamics, all consumed energy must ultimately be released into the atmosphere as waste heat. We use infrared telescopes to detect precisely such telltale heat radiation from ringlike structures of this kind.
You also assume that extraterrestrial civilisations use black holes as gigantic hard drives – which could also help prove their existence. Can you explain how this might be done?
Osmanov: Any advanced civilisation requires enormous amounts of computing power. Small black holes have been shown by mathematics and quantum physics to be the most efficient data storage systems in the universe. If a civilisation were to use a small black hole as a quantum computer, a specific type of radiation would be emitted – known as Hawking radiation. Among other things, this radiation contains elementary particles called neutrinos. If large neutrino observatories detect certain unnatural energy spikes, this could be evidence of a galactic supercomputer. We have put together information for observers with a precise description of what they should be looking out for.
Would such research even be possible without international cooperation?
Osmanov: Only a handful of research institutions worldwide are equipped to pursue this kind of research. The number of researchers is also relatively small. Cooperation is therefore vital for my field of research – as are funding programmes such as those run by the DAAD. Its grants have enabled me to collaborate with Max Planck institutes in Heidelberg and Munich. These projects were very important for my later career.
If superior civilisations really did exist, wouldn’t they know about us?
Osmanov: It is perfectly possible that they have already found us. However, we must understand the cosmic scale we are talking about here. We only developed the technology necessary to broadcast powerful radio signals around 100 years ago. Moving at the speed of light, these signals have so far filled a bubble in space with a diameter of roughly 100 light years. That’s just a tiny fraction of our galaxy. If a Type II civilisation exists within this bubble, it will know about us. If it is further away, evidence of our existence simply hasn’t reached it yet. —
Professor Zaza Osmanov is an astrophysicist and a partner of the SETI Institute (Search for Extraterrestrial Intelligence) in the USA. He is currently conducting research at the Free University of Tbilisi in Georgia, where he is the associate dean of the School of Physics. As a DAAD alumnus he continues to promote academic exchange and support the work of the DAAD, for example as a jury member of the 2025 Falling Walls Lab in his homecountry Georgia.