I declare this to be my third favourite book of all, after Frankenstein and Neuromancer. It is ultra-realistic science fiction (though badly flawed by modern standards), and explores both the academic and political movements that take place when a large black cloud appears and takes up the space between the Earth and the Sun. It gives some real insight into the machinations of international (although heavily British-biased) government in the 1950s.
Every one of the personalities is obviously based on an actual person in Fred Hoyleʼs circle. Every nuance of their character comes through, the implied seniority and authority in driving actions along, and the conflicts between them caused by nothing but personality clashes.
It turns out that the Cloud is sentient, and chooses to only communicate with the English who made first contact. The onward implication that Britain would then become the epicentre of global communications, and would thereby dictate terms to the world, is a stretch, though one well within the stride of this confident and experienced author.
When eventually other nationalities do try to take matters in their own hands, they involve trying to destroy the Cloud, with almost catastrophic effects for the whole of humanity. The Brits explain how the Earth is diverse, how the Cloud is interfering with life here, and how preservative the human race is in general, eventually leading to the Cloud leaving us in peace.
At times it feels like the effects of the cloud, the global warming and then cooling, are put too much to one side to concentrate on the machinations of government, and the long-term impacts on the global climate and the socio-economics of the surviving population are not explored at all, indeed, they seem to be misunderstood. Most likely this is just a sign of the times: the book came out in 1957. The justification is that only people in poor countries suffer, whereas the rich Western world is able to ride out the effects with the help of the available technology, and this book is rooted firmly in the West. This aspect of the work definitely comes across as very dated and biased.