And these being fans of science fiction, they come in all shapes and sizes. They come as Klingons. They come as Daleks. They come to celebrate a genre that has produced a group of followers that are as strange as some of the storylines.
Every year they gather to discuss what is new in the world beyond our own. But Orbital 2008, Britain's 59th annual National Science Fiction Convention, which started yesterday, is dominated by the death of Clarke last week. And that has meant a hastily re-arranged programme to celebrate the legendary figure's achievements with a series of talks and lectures.
So, there is no place in this year's program for Klingon language seminars. Of course, this may have come as a disappointment to the man in the Worf outfit supping a pint of lager in the foyer of Heathrow's Raddison hotel, but for the rest of the 1,500 sci-fi fans gathering for the three-day celebration of all things intergalactic yesterday, there were plenty of other things to occupy them.
According to Charlie Stross, one of Britain's most successful sci-fi writers, Clarke, along with Robert Heinlein and Isaac Asimov, dominated 20th-century writing. "He was the last of them to die. But even if he had not written any science fiction he would have left his mark on the world as the creator of the communications satellite. He did the maths to demonstrate how it would work. He was scientifically rigorous, but also highly readable," he said.
Yet, like Captain Kirk and co, there is it seems more to 21st-century science fiction that Arthur C Clarke.
Among the other topics up for discussion this weekend is the thorny issue of Doctor Who, which despite having won over huge new audiences has received a muted welcome among hardcore fans. Proceedings kicked-off with a discussion over whether its creator, Russell T Davies, was the saviour of British sci-fi, or "just a mad fan with a God complex".
And though it may come as a shock to its fans, the BBC time-slip drama Life on Mars and the follow-up Ashes to Ashes were also generating fierce debate, alongside more traditional subjects such Blake's 7's famously wobbly sets. Tomorrow, delegates will debate whether Sam Tyler's amnesia and time-travelling skills can be explained by the fact that he is really the Master from Doctor Who.
But there was also something on offer for the fetishist wing of the movement in the form of a nightly series of workshops on bondage – topics covered include everything from wrist and ankle ties to whole body harnesses.
And the on-going controversy over Slash, where sci-fi or fantasy characters are placed in on-line relationships – often seeringly sexual – was also being given an airing under the title: "Where Does Slash End and Porn Start?".
According to the organising committee member John Wilson, such tendencies are easily explained. "The majority of sci-fi fans are brighter and more curious than the rest of the population. This means we also have a higher proportion with less vanilla tastes than the rest of the world – this is true when it comes to sex as with everything else. The thing here is that it is purely fantasy – it is all about role-playing." Try saying that in Klingon.