But can nostalgia work in reverse? The film “Voyage to the Prehistoric Planet” (1965) was set in 2020, and imagined humankind as having mastered space travel, zipping off to fight man-eating plants on the surface of Venus.

Likewise, “Back to the Future, Part II” (1989) assumed that, by 2015, consumers would be able to buy hoverboards that actually defied gravity — not just ones that either still rely on wheels, such as today’s self-balancing scooters, or that sit on an air-filled flexible skirt like 20th-century hovercraft.

Which other technological marvels have failed to materialize, and what is the scientific reality?

It has been 92 years since the August cover of Amazing Stories magazine featured a man in a scarlet jumpsuit floating over the sky. Today, they exist: You can reserve a wearable turbine T-73 from Jetpack International for a very reasonable $200,000.

As for a more functional model: as well as the commercial parameters — safety, portability, fuel efficiency — there’s also the small matter of the piloting skills of the buyer. Factor in problems arising from flight path interference, and investors may feel they’re looking at another Ford Edsel.

“By the turn of the millenium [sic] a technology known as VIRTUAL REALITY will be in widespread use. It will allow you to enter computer generated artificial worlds as unlimited as the imagination itself.” So begins sci-fi movie “The Lawnmower Man” (1992), whose intro was at least taken seriously by TV commissioning editors: the following year would see a short-lived British game show, “Cyberzone,” where contestants lumbered around a digital metropolis, while one episode of 1995’s “The Outer Limits” imagined virtual reality headsets so immersive they gave their wearers clairvoyance.

Nearly 30 years later, it seems technology is catching up with its 1990s prophecies: the Oculus Quest gaming headset had sold 400,000 units by the close of last year. But according to international research, widespread VR still has an ethical barrier to overcome. It seems few have considered the negative effects of prolonged recreation in a digital playground, such as false memory brought about by identity hacking (where VR realizations of groups or individuals can be deliberately manipulated), and the decompression effect of reentering normality. Maybe, as with the many attempts to revive 3-D television, people aren’t yet ready for widespread total immersion.

Moving objects instantaneously has been an enduring fantasy for over a century. From the vanishing cat of Edward Page Mitchell’s 1877 story “The Man Without a Body” to the 1956 novel “The Stars My Destination” and its citizens capable of “jaunting” using willpower, humans have longed to be zapped from A to B.

The good news is the phenomenon exists — provided we’re not the passengers. Quantum teleportation involves “entangling” separate, unconnected particles until their statuses match. Qubits of information can be sent between quantum computers, and recently enabled a “jamming session” where Alexis Kirke, a PhD holder in arts and mathematics at the University of Plymouth, used an Australian IBM quantum computer to “accompany” him as he played the “Games of Thrones” theme. Not as exhilarating as interdimensional transport, perhaps, but the manufacturer that perfects a home computer capable of quantum teleportation will be a game-changer.

If you believe “Terminator 2: Judgment Day” (1991), you’ll know that Aug. 29, 1997, was the date that “neural net computer” Skynet achieved self-awareness and decided to wipe out its human creators. If you believe “Her” (2013), we’re only a few years away from a Siri-like virtual assistant that’s able to seduce Joaquin Phoenix. So where are the supercomputers of today that enjoy flirty dialogue, and launching ICBMs?

One answer is the University of Pittsburgh, where the only uprising being planned is advancements in prostate cancer diagnosis. After being shown slides of corrupted tissue from patient biopsies, a medical AI was able to detect cancer to a degree of 97 percent specificity, and 98 percent sensitivity. It also flagged six slides that the human pathologists failed to diagnose.

Does this mean medical professionals should be concerned for their future? That may depend on whether patients are comfortable with the absence of a human bedside manner.

If we can’t create an evil master control program, can we at least create the mannequin version? It’s nearly 50 years since Michael Crichton directed “Westworld,” adapted from his novel about a dust-bowl theme park whose chief robot cowpoke turns rogue and begins dueling for real.

Androids that convincing might not yet walk among us, but they certainly exist, albeit in a more benevolent form. At the Kodaiji Buddhist temple in Kyoto, Japan, enlightenment seekers can enjoy sermons preached by Mindar, a robot speaking as Kannon Bodhisattva, the Buddhist deity of mercy. As one observing priest remarked: “It will just keep updating itself and evolving. That’s the beauty of a robot. It can store knowledge forever, and limitlessly.”

The only thing stealthier than a machine priest could be something you can’t see at all. Artificial invisibility has been dreamed of for decades, perhaps most fondly imagined in the 2005-set video game “Metal Gear Solid” (1998), which allowed players to use stealth camo to evade enemies.

We may already be on the cusp of such technology. European scientists have recently discovered that a key part of quantum computers — photonic circuits — can turn invisible when red femto­second laser pulses are shone through them. Not quite the magic cloak Harry Potter fans long for, but proof that high-tech invisibility has moved beyond the “Ghost camouflage” that was recently able to evade night-vision.

When imagining 2015, the screenwriters for “Back to the Future, Part II” got some lucky picks: gargantuan TVs, thumbprint transactions and a lasting obsession with the 1980s (as well as Michael Jackson’s performing hologram). But the levitating hoverboards, whispered to be real at the time of the film’s production, are still just a pipe dream.

That didn’t stop French inventor Franky Zapata attempting to cross the English Channel on a hoverboard last year. It might not have been the model as flown by Michael J. Fox in the movie — that appeared to use a form of flux pinning (as opposed to a flux capacitor), while Zapata’s device was jet-based, and ran off a kerosene-filled backpack — but it allowed its pilot to float from Calais to Dover in 22 minutes.

Whether the board will become commercially viable is open to speculation; die-hards who still want the Mattel version from the movie will have to contend with a desktop replica on Amazon.