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37 JULY-AUGUST 2022 ASTRO PUBLISHING spread far beyond their origin in space, time and scope. In practice, the Drake equation cannot repre- sent all of this. To bridge the gap, Wright and colleagues propose two new “Drake-like” equations. The first variant is: N(bio) = R * f p n p f l L b and is designed to estimate the number of planets with biosigna- tures detectable from Earth with current instruments and based on today’s knowledge. The term f l is here interpreted as the fraction of planets that develop biospheres comparable to ours, while L b is the average time during which a bios- phere is detectable. The second variant is: N(tech) = R * f p n p f l f t L t and provides an estimate of the number of planets with technosig- natures, as we can expect based on our experiences. Here, f t expresses the fraction of planets hosting intel- ligent life that produce technosig- F rank Drake speaking at Cornell University in Schwartz Auditorium, 19 October 2017. More than sixty years have passed since this astronomer proposed his famous equation, which still today generates discussions among astrobiologists. [Amalex5] natures and is the equivalent of f i f c in the canonical form of the equa- tion. L t , on the other hand, is the time during which the technosigna- tures remain detectable. If the evolution of life on Earth were the galactic standard and the tech- nological level reached by humanity were the highest in the Milky Way, we could say that N(bio)>N(tech). However, the researchers rightly point out that although technology originates from biology, it can also exist regardless of the latter in vari- ous forms that the original equation does not capture. We can take the example of a technology resistant enough to sur- vive the biosphere that created it and capable of producing technosigna- J ohn Von Neumann, an eclectic and controver- sial genius of the twenti- eth century, is the father of the Theory of Self-Re- producing Automata, ac- cording to which, in the future, machines could replicate themselves re- gardless of the existence of human beings. This would allow them to spread across the galaxy in astronomically short times.