A love for the universe in Cosmos

Cosmos is a joyous romp through space and time; genuine wonder at the beauty of galaxies, the music of spheres, the mountain of history it took to get us to the knowledge we possess about the universe today. It is not so much a science book as it is a book about everything, giving us much-needed context on the scale of things — how vast a universe measured in light years, how temporary a human lifespan, how microscopic the building blocks of matter — and how splendous the whole concoction: tiny electrical forces of push and pull holding together entire galaxies, and creating beings capable of marvelling at it all.

I especially enjoyed the chapters bringing me to Venus, Mars, and Jupiter, and allowing me to bear witness to the birth and death of stars. Venus: a hellish place with 480°C surface temperature and 90 atmospheres of surface pressure, and an eternal rain of sulphuric acid in the atmosphere which never reaches the surface due to the high temperature. Mars: open bodies of water are impossible because the pressure is too low to keep it from boiling. Jupiter: a failed star radiating light in the infrared spectrum, big enough to contain a thousand Earths. And stars: their gravity brings particles close together for nuclear forces to overcome the natural repulsion between protons and electrons, fusing hydrogen particles together to form helium and giving off gamma photons in the process. When all the hydrogen is fused, the mass of the star determines its eventual fate into black dwarf, neutron star, or black hole. Along the way, the methods that astronomy has developed, like astronomical spectroscopy, to deduce these faraway conditions, and the expeditions — including the failures — to these planets for verification.

Of noteworthy mention is Sagan’s inclusion of the process of arriving at our present conclusions, as he briefly presents a history of mistaken beliefs continuously corrected by scientific inquiry. What this serves to reinforce is the idea that what we know about the world is subject to change — but this is beautiful because we, coming later on the timeline of human civilisation, can still contribute to this giant repository of knowledge.

Science is not just a pure pursuit of knowledge; it is very much affected by prevailing systems of power and beliefs. Sagan synthesizes thousands of years of (mostly Western) civilised history to present an argument for the causes of the acceleration and deceleration of the rate of scientific discovery. A great scientific boom occurred around the 5th to 6th century BC in Ionia, with the seeds of thought for a world formed not by Gods but by natural processes, the establishment of medical tradition (Hippocrates), the conception of the atom (Greek for unable to be cut), and many more, because, Sagan believes, it was comprised of a group of islands with no single concentration of power to enforce social and intellectual conformity. Diversity is the key ingredient to progress, providing a healthy cross fertilisation of ideas. Yet its reliance on the slave economy led to a lack of impetus for advancing technology, as well as an increased disdain towards manual labour, which was placed in opposition to spiritual pursuits, associated with the so-called elites. Ironically, Pythagoras and his followers, with their belief in pure theory unsullied by the world, contributed to the demise of progress, and would later influence a Christianity that suppressed free thought in order to maintain its hold on power.

I found the last couple of chapters — arguments for the possibility of life elsewhere, and a warning against self-destruction through war — less satisfying than the rest of the book, as it wades into social science territory that comes off less as condensed material than as simplistic models. I raised my eyebrows at Sagan’s summary of a James W. Prescott’s findings — cultures lavishing physical affection on infants and allowing expression of sexual activity in adolescents are disinclined to violence — which Sagan proffers as the solution to world peace. While well-intentioned, it does not stand up in the strength of its argument to the rest of the book, and would perhaps have been better left as a couple of concluding paragraphs painting our possible paths: humanity annihilated through nuclear wars, versus the continued potential for awe at the worlds left for us to discover.

This is a book in love with the universe; you will come off it with a renewed sense of wonder, and a growing curiosity for all things space and quantum.

Rating: 4.5/5

— Cosmos (Carl Sagan, 1981)