by Kelvin F Long
Recently I published one of my more speculative papers to date. I derived a very simple equation to estimate the time of first contact with Extraterrestrial Intelligence (ETI). This calculation neglected the possibility that they would come here and only considered (as a thought experiment) the possibility of us interacting with them either in deep space (in the space between the stars) or in their planetary system of ETI origin by one of our probes. The paper emphasised two key developments which will enable first contact being; advanced propulsion capability and the discovery of many exoplanets through astronomical observations. This calculation depended upon two factors (1) the growth rate to mature our technological propulsion capability to the appropriate velocity, where as a case study I examined up to 0.1c (2) the distance to the astronomical target where it is assumed an exoplanet has been discovered with the appropriate conditions for life, for which we may choose to send such a probe. I concluded that for interstellar targets out to 10 LY first contact may occur any time in the next ~25 - 174 years. For targets out to 100 LY first contact may occur any time in the next ~114 - 1,044 years. For targets out to ~200 LY first contact may occur any time in the next ~214-2,000 years. The range of values was a function of the growth rate parameter index. Any maturation of technology into the relativistic velocity regime will only serve to highlight these conclusions.
On the basis of the above I recommended that astronomers should give particular attention to any exoplanets within ~200 LY distance. Since this neglected the possibility of them coming here, and given the age of our sun relative to other stars, the probability that they would have been here already or at least had knowledge of us was argued to be high. This also implied that the scenario of an ETI presence in our own solar system was also high. Although, these conclusions do depend on the assumption of a galaxy that is filled with independent biogenesis which emerges purely as a function of chemistry and the rise of intelligence in the first place and so is the major uncertainty on any conclusions. This also makes certain assumptions about the nature of intelligent life as organic/chemical in origin when in fact it could be defined more broadly but this is beyond our current knowledge (i.e. Schrodinger's definition of life being a resistance from decay to thermodynamic equilibrium).
The paper was:
K. F. Long, The Temporal Contact Equation: An Estimate for the Time of First Contact with ETI, JBIS, 76(11), 279 - 282, November 2023.
Vorlon Cruiser Spacecraft from Babylon 5