Gravity's Rainbow is a 1973 novel by American writer Thomas Pynchon. A long and deeply complex sci-fi novel, it's the one novel most famous for people being unable to get through it, than have actually read it. Although someone must have read it, as it won the National Book Award for Fiction when it came out in 1974. It's also listed often in the USA and UK as one of the best novels of the 20th century. Although, it's rumoured that many people claim to have read it, who actually have given up only a few hundred pages in.
So what's it about? The "rainbow" in the title refers to the arc of the V2 rocket developed by the German's during WWII. Various characters look for the secret of the Schwarzgerät or "black device" contained in the V2s. The title also refers to the property of gravity, that has the ability to bend light, proven through the production of a rainbow. And the Poisson distribution referred to in the novel, regarding the distribution pattern of rocket hits.
As said earlier many who have entered this enormous 300,000 word novel haven't made it through. Some falsely claim to have done it alone, some admit they only made it through with the help of someone else who'd been through the arduous journey before them and could serve as guide. This bloated tome was a piece of its time, that likely wouldn't even be considered for publication today. As it would be viewed as self-indulgent over-wrought nonsense. The rejection letters from the publishers would themselves amount to a bleak dystopian analysis of a postmodern world, out of step with the novelists attempting to push the furthest boundaries of the art. A story of how the machine of market forces has quelled and all but destroyed the possibility for great pieces of transgressive art to rise-up and be recognised for their difficult complexity, as a metaphor for society as it really is when a literary mirror is held up to it.