Terrestrial Life in Light of the Copernican Principle

Abstract

While other solar systems are now known in abundance, so far only one example of life is known. Thus, terrestrial life represents just one data point. Thus, extrapolating from terrestrial life to potential life elsewhere in the galaxy and beyond is often considered a limitation in the search for different life. In other words, to extrapolate from terrestrial life to life elsewhere is to say that terrestrial life represent universal life, this is considered to be a geocentric approach. However, according to the Copernican principle, it is the other way around. It is a geocentric view to claim that terrestrial life should be different from other life in the universe. For if life elsewhere is not like terrestrial life, then it is ipso facto different life; more precisely, if terrestrial life does not represent general life, then that life must represent special life, which the principle states it is not. Thus, in this work the Copernican principle has been utilized as a measure for probability, as the criticism is based on the implicit assumptions that different extraterrestrial life exists. So if there are different fundamental forms of life, then there will also be differences in the probabilities with which they can arise in the form of a probability scale. Thus, an example shows that even if it is not is a given that terrestrial life cannot belong to the less numerous categories, it is more reasonable that terrestrial life belongs to the most numerous category due to arising from the simplest conceivable complexity of life. This is important in that not only can much be known about the majority of life elsewhere, but boundaries for categories of life as we do not know it can be set up at the same time. Thus, a Copernican-Darwinian principle offers a fruitful tool for astrobiology and the search for life elsewhere in the galaxy and beyond.