The Drake equation is one of the most well-known in astronomy. It has been debated since Frank Drake in 1961
What's wrong with the Drake equation?
The Drake Equation is a formula designed to determine the number of extraterrestrial civilizations in the Galaxy with which humanity has a chance of making contact.
The formula looks like this:
N = R⋅fp⋅ne⋅fl⋅fi⋅fc⋅L
N is the number of intelligent civilizations ready to make contact;
R —the number of stars formed per year in our galaxy;
fp —the proportion of sun-like stars with planets;
ne —the average number of planets (and satellites) with suitable conditions for the emergence of civilization;
fl — probability of the origin of life on a planet with suitable conditions;
fi the probability of the emergence of intelligent life forms on a planet on which there is life;
fc is the ratio of the number of planets whose intelligent inhabitants are capable of contact and are looking for it, to the number of planets on which there is intelligent life;
L is the time during which intelligent life exists, can come into contact and wants to do so.
The equation itself was centered aroundsearch for radio signals. However, its formulation implies that in the search process people will find so-called “biosignatures”, and not technological traces of civilizations. For example, astronomers can find methane in the atmosphere of a planet, which is a clear sign of life, even if This planet has not yet developed intelligence.
- Biosignature - any manifestation of the consequences of life, scientifically proving the existence of life in the past or present.
- A technosignature is any measurable property or effect that scientifically proves the existence of a technology in the past or present.
At the same time, the search for biosignatures itself was impossible,когда Дрейк писал уравнение. Но сейчас ситуация изменилась, особенно с запуском телескопа «Джеймс Уэбб». Возможно, пришло время изменить исходное уравнение, чтобы лучше отразить новые поисковые возможности ученых. Один из способов — разделить уравнение на два отдельных, отражающих поиск биосигнатур и техносигнатур соответственно.
Miscellaneous signatures
According to a new study by researchers at the University of Pennsylvania, biosignatures are likely to beLogically, this follows from the fact that the number of planets on which a technologically advanced civilization develops is much smaller than the total number of planets on which life originally originated. After all, it took Earth about 4 billion yearsafter the appearance of the first life, to develop an intelligent civilization.
What does the equation look like now?
Scientists have modified the original equation, reducing the probability of the existence of a technologically advanced civilization to the product of two factors.Now the formula looks like this:
A = Nast⋅fbt
A is the number of all technologically advanced species that have ever existed in the observable universe;
Nast is the number of potentially habitable exoplanets in a given region of the Universe;
Fbt is the probability of the development of a technological civilization on a given planet.
Above is the Drake equation in its usual form, below is a version that combines a number of parameters together.
Photo: Rochester University
All along, we've been looking for extraterrestrial life in the wrong way, focusing our attention on the search for biosignatures, according to a new study. And, perhaps, the emphasis on technosignatures will fix everything.
Why is the search for technical signatures better?
One of the fundamental characteristics of the technology is that while it can arise on a planet with a biosphere, it canleave it to stay. Thus, the Earth has sent many signals, messages, and probes beyond the Earth and even the Solar System. This has a significant impact on another factor in the Drake equation – L, or the length of time it takes for a signal to be detected.
As the authors of the new work note, there are four factors that point to the advantage of finding technology from extraterrestrial civilizations.
- Technology can outlive the biology that created it for a long time, and even destroy the biosphere that created it. But it can still be detected even from a great distance. Depending on the reliability of the technology, this could happen millions or even billions after the extinction of a civilization.
- Technospheres have the potential to outnumber biospheres. For example, if lunar colonizationsteadily advancing over the next few hundred years, the Moon will becomea world without a biosphere, but it will be distinguished by a technosphere.
- The technology itself could become self-replicating, like the von Neumann probe.Technosignatures can exist without a planet at all, in the form of spacecraft or satellites. In fact, it canbe even the most common form of them in the Galaxy. Thus, the limiting factors of the Drake equation, which are directly related to the planet, do not apply to technology.
- Another factor is how easy it will beThe authors of the study note that the detection of biosignatures is a challenge — in fact, we can't even detect Earth's biosignature at the distance of Alpha Centauri, the closest star system to us.Data from the James Webb Space Telescope can help, but even then , radio astronomy projects like the Square Kilometer Array are much better suitedto detect telltale signs of technology.
There is a problem
To find both types of signatures, it is difficult to separate the desired signal from theFor example, distorted spectral analysis or heat signatures. However, in the paper, the authors of the study convincingly argue that technosignatures can at leastbe much clearer than any biosignatures.
What's the bottom line?
All of this means that scientists may have been focusing on the wrong thing for the past few decades.Instead of looking for signs of life in the past and present, we should pay more attention to the search for technosignatures.In any case, the search for extraterrestrial intelligence must continue.Even if it is already extinct, leaving behind only the last message.
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