What is cosmology anyway?
Science tears things apart into constituents of greater and greater specialization – often into smaller and smaller pieces – and devotes closer and closer attention to detail. Cosmology is the one science in which specialization is rather difficult. While other scientists are pulling the universe apart into progressively more detailed pieces, the cosmologists are endeavouring to put the pieces together to see the picture on the jigsaw puzzle. ~ Edward Harrison, Cosmology: The Science of the Universe
As a PhD student dabbling in cosmology, I would define it as the study of the Universe on its largest scales. My idea of cosmology is purely naturalistic, concerning the physical Universe and our scientific models of it that Edward Harrison refers to as ‘universes’. Harrison however, even dares to extend its scope, defining cosmology as the ‘joint enterprise by science, philosophy, theology and the arts that seeks to gain understanding of what unifies and is fundamental.‘
We often classify cosmology as a branch of astrophysics (or even particle physics), but how can this be, considering that cosmology seeks to understand the Universe as a whole? Apart from the large scale structure of the Universe (all matter, energy and space-time) and its evolution, Harrison includes the origin of life and intelligence as a cosmological subject as well.
So Why Study Cosmology?
Cosmology and society are intimately related. Where there is a society, there is a universe, and where there is a universe, there is a society of thinking individuals. Each universe shapes the history and directs the destiny of its society. ~ Edward Harrison, Cosmology: The Science of the Universe
Postmodern philosophers have their own word for what Harrison refers to here as ‘cosmology’/’universe’. They call it a ‘metanarrative’, or in other words, a ‘worldview’. This metanarrative – the overarching story – plays a huge role in influencing human society, since how we live is determined by the stories that govern us, and the lenses through which we view the world. For a Christian, this metanarrative is the story of Creation, Fall, Redemption and New Creation. Defined this way, cosmology will definitely have an impact on society.
But what about cosmology as a science? Why spend billions of dollars on high-tech instruments to observe what the Universe looked like 13 billion years ago? It remains to be seen if cosmology will ever result in concrete benefits to society in the way the other sciences have done – e.g. medicine, computers, etc. I believe the benefits of cosmology go deeper than that, having possibly emotional or even spiritual significance. There is this insatiable curiosity that has dogged our species ever since we began looking up at the night sky and wondered about the meaning of it all. We are curious creatures. We are drawn towards mystery as a moth is drawn towards a light bulb.
The same thrill, the same awe and mystery, come again and again when we look at any problem deeply enough. With more knowledge comes deeper, more wonderful mystery, luring one on to penetrate deeper still. Never concerned that the answer may prove disappointing, but with pleasure and confidence we turn over each new stone to find unimagined strangeness leading on to more wonderful questions and mysteries – certainly a grand adventure! ~ Richard Feynman, The Value of Science
Then who are cosmologists?
Professional cosmologists are relatively few; they are well-versed in mathematics, physics, and astronomy, and they study the evolution and large-scale structure of the physical universe. In general, however, whenever a person seeks to understand the Universe, that person becomes a cosmologist. When we stand back from the study of a specialized area of knowledge, or just step aside from our everyday affairs, and reflect on things in general, and try to see the forest and not just the trees, the whole painting and not just the dabs of paint, the whole tapestry and not just the threads, we become cosmologists. ~ Edward Harrison, Cosmology: The Science of the Universe