The Limits of Cosmology

Amedeo Balbi on The Limits of Cosmology

When attempting to discuss what a certain discipline can or cannot know, one should keep in mind, as a cautionary tale, the famous case of philosopher Auguste Comte. Writing in the first half of the nineteenth century, he stated that astronomers would never be able to ascertain the chemical composition of celestial objects. However, only a few decades after Comte’s prediction, Kirchhoff founded spectroscopy and managed to identify chemical elements in the atmosphere of the Sun.
    Cosmology is arguably one of mankind’s boldest enterprises. It tries to scientifically understand the origin, evolution and structure of the universe as a whole. In doing so, it has to rely on a certain set of observational data (what we see of the cosmos) whose collection cannot be repeated under different conditions; furthermore, it has to interpret such data according to a set of physical laws whose validity was mostly assessed in laboratories on Earth. Most cosmology is based on extrapolations of known physics to uncertain territories, and on indirect evidence derived from the behaviour of the part of the universe we can observe. We happen to live in the golden age of cosmology—for the first time in the history of mankind we are able to scientifically describe the overall structure of the universe. However, to some extent, it is surprising that we have managed to make some sense of the universe at all. Continued...

This essay is one of the winners from FQXi's contest on What Is Ultimately Possible in Physics?