In 1902 Lu Xun translated Jules Verne’s From the Earth to the Moon into Chinese from the Japanese edition. Science fiction, he wrote in the preface, was ‘as rare as unicorn horns, which shows in a way the intellectual poverty of our time’. Not any more. The Three-Body Trilogy by Liu Cixin has sold 500,000 copies in China since the first volume was published in 2006 (it will come out in English in the autumn). Liu, an engineer, is one of the so-called ‘three generals’ of contemporary Chinese science fiction, along with Wang Jinkang and Han Song.

Politicians’ fictional namesakes aren’t hard to come by: as well as George Osborne in Vanity Fair, there’s a one-legged vagabond called Tony Blair in Uncle Rutherford’s Nieces: A Story for Girls (1869), and in David Cameron’s Adventures (1950), the eponymous hero is kidnapped in Aberdeen and sent to work on a plantation in Virginia. In Agent of Chaos by Norman Spinrad (1967), Boris Johnson is the unlikely leader of the Democratic League, an interplanetary resistance movement fighting against the totalitarian regime of the Hegemony, which has turned the entire solar system into a surveillance state. Their political efforts are hampered by his bumbling nature. ‘Boris Johnson was quite willing to babble on – and did so at every opportunity – but the man was a fool.’

There are the books you like, and the books you can recommend, and the books around which you can muster arguments. And then there are the books from which you can get no aesthetic distance at all. Often they’re books about childhood, or about something or somewhere you knew as a child. They can also be books about books. Among Others by Jo Walton, is one such book for me, and not for me alone: last week it picked up the British Fantasy Award, having already won the Nebula and the Hugo for the year's best science fiction novel. The two awards together describe the state of SF (one’s voted on by working authors, the other by fans); when the same book wins both, it’s a recommendation, and it says something about the state of the genre. And yet Among Others is not science fiction at all, if you judge by its plot.

Apocalypses aren't what they used to be. Thirty years ago, science fiction stories about sentient computers taking over the world tended to imagine them trying to wipe us all out using nuclear bombs (The Terminator, War Games). These days, if Robert Harris's new novel, The Fear Index, is anything to go by, the rogue AI's weapon of choice is the financial markets. 'Tales of computers out of control are a well-worn fictional theme,' Donald MacKenzie wrote in the LRB earlier this year,

There’s a TV reality show in the US (Same Name) about people with the same name swapping lives. I feel confident that the producers won't be calling on me. But a few weeks ago, Google alerted me to the improbable existence of another Ange Mlinko.

In Understanding Media (1964), Marshall McLuhan distinguished between 'hot' and 'cool' media: hot media, like the radio, are 'high definition' but 'low in participation'; 'cool media', like the telephone, are 'low definition' but 'high in participation'. (In the early 1960s, TV was 'cool', compared to the 'hot' movies. Obviously that was long before the arrival of hi-def.) Predictions about the way technology is heading, whether made by SF writers or tech companies, tend to assume the future will be hot. Characters in Brave New World go to the Feelies. Thirty years ago, everyone (well, maybe not everyone) imagined that by now we'd be watching holographic movies and wandering around with virtual reality helmets on. But no one foresaw the rise of text-messaging or Twitter. Michio Kaku's whiggish Physics of the Future, published last month, follows the trend, confident that the future will be lived in high definition.

My parents were science fiction fans in the late 1960s and early 1970s. In the 1980s, between the ages of about 10 and 13, I read quite a lot of their paperback collection: Isaac Asimov, Poul Anderson, Harry Harrison (some of his were for children and some were mordantly political) and Larry Niven, best known for his novel Ringworld. I didn't know at the time that Niven was and is a resoundingly unhip figure even by the standards of science fiction novelists.