If you visited the 2014 Cannes film festival, or are planning to attend the Melbourne international film festival (Miff), you might assume that Australian filmmakers specialise in science fiction. Over the decades, we have had a few forays into cinema’s most popular genre, but unless you count Sydney-filmed, Hollywood movies like The Matrix and two Star Wars films, we haven’t done many. It’s not that we don’t like sci-fi (or SF to the serious fans). Australia has a passionate community of geeks, who attend Comic-Cons in force. However, Australia’s small filmmaking scene could never afford a Matrix budget.

That was then, of course. In May, two of the three Australian features at Cannes were science fiction. The Rover, the sophomore film from Animal Kingdom writer-director David Michod, was released in June. This is SF without laser beams or spaceships – something Australian movies have done effectively in everything from Mad Max to Tomorrow When the War Began. Like those films, The Rover is set in a dystopian future, a lawless society 10 years after the Collapse (an event that is never explained).

Australia’s other SF film to wow Cannes audience was These Final Hours, which premieres on July 31, set in the last 12 hours before the end of the world. Like the collapse of The Rover, the apocalypse is unexplained, simply providing an excuse for writer-director Zak Hilditch to explore a few scenarios.

“I wouldn’t say I’m a huge sci-fi nut,” says Hilditch, “but I really do like science fiction films that have more going on underneath the surface… With These Final Hours, it’s basically an apocalyptic thriller, but within that, I do want to also show that mankind is capable of very beautiful things on the last day, not just everyone’s gone crazy and everyone’s hacking each other with machetes.”

These Final Hours revolves around James (Nathan Phillips), who plans to spend his final moments attending an orgy with most of his friends, but instead devotes his last day to a young girl (talented newcomer Angourie Rice). Thanks to moments of heroism and dry humour, it is less downbeat than you might expect. Still, it’s not exactly joyous.

Again, Australian films have often visited the apocalypse, going back to the Hollywood production On the Beach (1959). Like Peter Weir’s end-of-the world classic The Last Wave (1978), the end in These Final Hours is viewed from a beach.

How did beaches, the quintessence of Aussie fun and freedom, become equated with the end of the world? Moreover, why does a nation known for its sunny outlook manage to make such gloomy SF films? When not suggesting that the future is terrible (as in The Rover), our filmmakers suggest that we don’t even have one.

Perhaps it’s because, even in these days of computer-generated imagery, our films can’t afford utopian futures, in which everyone flies around over ultramodern cities. Also, even if we don’t have the SF budgets, we certainly have the landscapes. Hilditch previously made the short film Transmission, about a pandemic that has wiped out most of humanity. It was filmed in the dusty Western Australian town of Kellerberrin. “You just go there in the summer and it is apocalyptic,” he says.

The Rover, set in a world suffering from climate change, was filmed in South Australia’s Flinders Ranges. “The film lives and breathes the landscape and the flies and the heat and the dust,” says producer Liz Watts. “It was that normal kind of drama that you go out into the desert, but you’ve got 100 people with you and you just hope the temperature keeps below 50 degrees so that we could keep working.” (Happily, it did.)

Woomera, another South Australian desert region, was the location of The Infinite Man, which premieres at Miff in August. This time, however, it was neither apocalyptic nor post-apocalyptic. In fact, the only mystery about this film is: why film it in Woomera?

The film can be filed into another category of science fiction, time-travel comedy. It’s the enjoyable tale of Dean (Josh McConville), who invents a time machine to help him set right issues with his girlfriend Lana (Hannah Marshall) and keep her away from his rival Terry (Alex Dimitriades). Naturally, he makes things even worse, competing for her attentions not only with Terry, but with his future self.

While writer-director Hugh Sullivan enjoys many time-travel films (mentioning La Jetée, Je t’aime je t’aime, Groundhog Day – “but I’m not even sure if that counts” – and Back to the Future), he doesn’t see any of them as major influences. However, he singles out Primer (2004), a cult film known for its clever but convoluted storyline. “It showed that you can make a time travel film on a very low budget, which I hadn’t really seen so much. It seems pointless to make a low-budget version of a pre-existing film. I had to find something quite unique. It almost worked because of the low budget, I suppose.”

Time travel seems to be all the rage at Miff, which opens with Predestination, one of those films known among SF fans as a head-tripper. Based on Robert Heinlein’s 1959 short story, All You Zombies, it has been expanded into an action thriller by identical twins Peter and Michael Spierig. Despite Heinlein’s title (and the fact that the Spierigs previously wrote and directed two zombie flicks), this is a zombie-free zone.

To say any more would be to risk spoilers. Suffice it to say that it concerns a significant meeting between two mysterious characters, played by Ethan Hawke and rising Australian star Sarah Snook, who excels in a challenging role.

Oh, and time travel. “The idea of being able to travel backwards or forwards in time and change the future or the past is such an exciting concept, filled with lots of dilemmas and paradoxes,” says Peter. “For a scriptwriter, trying to find out how it all works can drive you a little bit insane.” Michael also gives credit to Primer, which “I’m still trying to figure out.”

Whatever they lack in budget, Australia’s latest science fiction films have the imagination and vision of that genre at its best. Like Star Wars, they are perhaps missing just one thing: actual science. They provide no scientific explanation for the time travel, the apocalypse, or the Collapse. But science fiction as a genre was originally known as speculative fiction. It’s about possibilities. For these movies, the question isn’t “how?”, but “what if?”

• Melbourne international film festival runs from 31 July to 17 August