"It's like going on a roller-coaster ride, you get a gut-lift," says Peters. "You don't move but you still get the gut-lift."

Demand for VR sex clips exploded in 2017. Views of VR clips on Pornhub, the world's biggest online aggregator of free adult content, nearly tripled in the 12 months to December, to 500,000 a day. That's still niche compared with the average 50,000 searches conducted across the site every second, but it's moving steadily in a northerly direction. Piper Jaffray, a US investment and management firm, estimates that VR porn will be a $US1 billion-plus business by 2025, up from about $US100 million ($135 million) this year. Last month, The Wall Street Journal declared: "The First Real Boom in Virtual Reality? It's Pornography."

With figures like that, it's worth taking a look at what VR might do to an industry seen by many as exploitative and damaging – and more widely, what technology might do to sex. The contraceptive pill revolutionised it in the 1960s, as have, more recently, dating apps like Tinder. Could VR sweep in the sexual revolution's next step-change? The possibilities are mind-boggling, from the use of VR in therapy for people with sexual issues and to counter plain old loneliness to the creation of unpalatable and illegal fantasies. Not to mention a more primal point: if virtual reality becomes as good as reality, will some of us give up on real sex altogether?

Silicon Valley pioneer Jaron Lanier formed VPL Research, the first company to manufacture commercial VR gear and software, in 1984. In his 2017 book, Dawn of the New Everything, Lanier writes of how, as a 15-year-old, he was consumed with the potential of VR, running up to strangers on the streets of New Mexico with religious zeal to blurt: "We'll be able to put each other in dreams using computers! Anything you can imagine! It's not just going to be in our heads anymore!"

Only in recent years, though, have the portals to this world of imagination – the headsets – begun to deliver, both in quality and cost. High-end models can cost more than $1000 but cheaper options which mount a smartphone can be bought for much less. And VR's appeal is extending far and wide, way beyond gaming, traditionally its most popular application. In healthcare it's being used to treat phobias and post-traumatic stress disorder, enable remote surgery and build connections with isolated family caregivers of elderly relatives. The canvas of imagination it offers is being used by artists such as Jess Johnson and Simon Ward, whose surreal, immersive exhibition, Terminus, opened at the National Gallery of Australia in May.

In his book, Lanier describes the difference between reality and its virtual cousin. "Reality, from a cognitive point of view, is the brain's expectation of the next moment. In virtual reality, the brain has been persuaded to expect virtual stuff instead of real stuff for a while."

This is more powerful than you might expect. Take a simulation called SnowWorld, designed by researchers at the University of Washington's HIT Lab to distract burns victims during painful medical procedures. Patients inhabit a virtual world of icy whites and frozen blues. Those who "throw" snowballs by clicking a button experience greater pain relief than those who simply view their surroundings. Cutting down side vision to make the illusion more complete also produces progressively better results.

Studies since SnowWorld's debut in 2000 have shown that activity in the brain's areas associated with pain shrank in its test patients. "Conscious attention is like a spotlight," wrote the researchers. "Usually it is focused on the pain and wound care. We are luring that spotlight into the virtual world."

Over breakfast in a Melbourne cafe, where we pick a remote table so as not to alarm nearby families, sex therapist Cyndi Darnell considers whether such therapeutic benefits could be applied to the sexual sphere. A Melburnian by upbringing, Darnell these days is based in New York, where she offers counselling, mentoring and educational services. "Most definitely it could benefit people with disabilities, people with injuries from accidents, back issues, people who don't have the mobility they once had," she says.

It could also be helpful for people who struggle with basic human communication, she adds, and for those wary of intimacy for other reasons. "For a lot of women who are either very shy, who come from sheltered backgrounds or have a history of sexual trauma, the thought of approaching a real human is a bit scary," she says. "So being able to conceptualise what it might feel like with another person of whichever gender in an erotic context … they get to try it that way and be in complete control. I think that would be extremely healing for a lot of women."

Some of those working in VR argue the technology works as an "empathy machine" and "de-objectifies" performers, both female and male. Ela Darling is VR content manager at US live-streaming website CAM4, which broadcasts solo sex performances online. She encountered the empathic potential of VR two years ago during a solo streaming sex show of her own. A man watching on his VR headset began trolling her via the text chat window. She ignored him as best she could, not wanting to stop her act. After about 10 minutes he apologised, telling her: "I came here to troll you, but you're really cool. I was bored. I was an asshole." He ended up giving her an online cash tip. "I think a part of that was that he felt present with me," Darling tells me via Skype from the US. "The immersive nature of VR made the difference."

The first neuroscience research into VR porn, published in June by Danish firm Neurons with VR porn company BaDoink VR, suggests that, compared with traditional porn, VR heightens emotional intensity and engagement with performers. A small sample size of five makes the results more indicative than predictive, but interesting nonetheless. "VR is constantly creating that sense of embodiment and empathy," says lead researcher Alexander Silva Lopera. "Being in someone else's body is what VR is all about, isn't it?"

Maree Crabbe is co-founder of the Victoria-based Reality & Risk program, which aims to understand how increasingly widespread pornography use is affecting young people and children. Crabbe believes "porn literacy" should be a regular part of the school curriculum. She worries that common mainstream porn tropes – gendered aggression and degradation of women, for example – will carry over into VR porn. She finds the notion of an empathic effect in VR interesting but not compelling. "Part of what porn does not do is support a viewer to understand the performers as multi-dimensional human beings, not just sexual beings – that they might be strong and smart and fun and care about things and other people," she says.

Futurist Ross Dawson splits his time between Sydney and San Francisco, delivering keynote addresses on subjects as diverse as financial services, social media and travel for companies including Google, American Express and PwC. In 2011 Dawson launched the Future of Sex website, which examines how technology – not just VR, but including the likes of robots and artificial intelligence – will affect sexuality. "We are being changed by technology," he says, choosing his words carefully as he pours himself a cup of tea in the lobby of an upmarket Sydney hotel. "Our sexuality – which is a fundamental aspect of what it is to be human – has been impacted in a significant way. And most people are oblivious to that."

He paints an incredible picture of the near future, one in which we may be able to change what we see and feel in real-life sex with the help of visual aids that augment what we see. Fancy making love to Brad Pitt rather than your husband? Or perhaps your husband, but what he looked like 10 years ago? A computer will eventually be able to overlay those faces onto that of your partner, perhaps through the use of contact lenses. It's already possible to transpose the face of someone – your ex perhaps, or a celebrity – onto the body of a porn actor, creating a revenge-porn video of an event that never actually happened. It doesn't take much imagination to see how dangerous this could be, within but also beyond the realm of sex. Such videos are becoming increasingly realistic, with the US Defence Department last week releasing a tool to help detect them.

"We're on the verge of being able to make somebody do and say anything we want," Dawson says. "We can get an image of Donald Trump jumping on the table and saying, 'I declare war,' or whatever." Dawson calls this outcome "the death of reality".

Ironically, for a trend associated with technology, VR sex has been hobbled for the want of it. That's changing. Facebook's Oculus Go VR headset, which retails here for from $299, doesn't require a smartphone to work and has already become "very popular with VR porn consumers", according to Scott Velvet (not his real name), who runs the US-based VR Pimp website, which rates VR porn. Producers have had to jerry-rig their own cameras – Lightsouthern's Michelle Flynn built one for about $3500; it looks like a robot head, with side-by-side GoPro cameras and fish-eye lenses as "eyes" and ear-shaped 3D microphones on each side – but fabricated VR cameras are now available for purchase. Early clips suffered from nightmarish failures of perspective and ballooning limbs but such problems have been solved, although even the best VR displays can still "freeze" or look pixelated.

The next step for VR is to allow the watcher to "enter" the clip and move around inside it, rather than simply be there as an observer, as is currently the case. Ross Dawson says that when the technology improves sufficiently – perhaps 10 to 15 years away – virtual reality will be indistinguishable from the real thing, which is when the fun – and the risks – will really start. Then, it will be possible to create interactive, imaginary people in an online universe that looks as real as the one we are all born into. Porn companies VRXCity and CamasutraVR are already building interactive virtual worlds similar to OASIS in Steven Spielberg's 2018 movie Ready Player One.

At this point, it's fair to wonder whether VR will replace plain old R. "There may be some people who prefer virtual sex over the real," predicts VR Pimp's Scott. "That group is probably going to get bigger and bigger as the virtual sex gets better and better … I'm sure some people will say, 'The heck with the real thing.'"

This eventuality, called the "sexual singularity", is something Jaron Lanier has little time for. "If a device calculates a perfect sexual experience for you, then what's really happened is that you've been perfectly trained in a Skinner box [a behaviour-conditioning chamber]," he writes in his 2017 book. "Don't be a lab rat."

Bryony Cole tracks how technology impacts sex in her podcast, Future of Sex, and wrote a manifesto on it in collaboration with Ross Dawson. They believe society needs to start a conversation on where all this is heading. A commerce graduate of the University of Melbourne who moved to New York in 2012, Cole became intrigued by VR a few years ago while compiling a report on nightlife trends, wondering what would happen when it was in every home.

She argues that VR sex constitutes a "middle space" between traditional sex and masturbation – particularly if internet-connected sex toys, a field with the unforgettable name of "teledildonics", are used. The websites that sell such toys (think app-controlled vibrators) have a similar feel to mainstream shopping sites, right down to the flashing alerts of other people's recent purchases, though instead of an expensive toaster you're informed that someone in Geelong has just bought an Autoblow2.

Full-body suits, which can mimic touch, will follow. One prototype has electrical thread laced throughout the washable two-piece; it "zaps" the point on the body corresponding to where someone else in that virtual world has "touched" you, stimulating the muscle there. The other person playing in this virtual universe might be in Prahran or Parramatta – or even Paris. "There is intimacy involved," Cole says. "You're connecting with someone else and it feels like you're touching, but we don't know what the effects are yet."

Her Future of Sex group will release a report on sex-tech, Virtual Intimacy, this month. In a broad overview, researcher Gavin Heaton says the research suggests VR is often a "gateway" to other experiences. "People will try low-end VR, say, 'This is really cool', and buy more impressive devices," he says. Many still want the physicality of real sex, he adds. "Tech allows people to explore their sexuality ... their sense of self, and change their selves in a way that's never been possible before."

Cole is optimistic that, in the end, most people will choose to augment rather than cut out reality. "Humans still want to be loved, they want to be seen, they want to be touched … Basic drives don't change, it's just the way we meet them that changes through technology."

To read more from Good Weekend magazine, visit our page at The Sydney Morning Herald or The Age.