If you've ever seen an alien in your daily life, there's a good chance you don't remember it. That's because of a small pen-like device called an "electro biomechanical neural transmitting zero synapse repositioner"—or the neuralyzer for short. As seen in "Men in Black," it wipes the memories of anyone who sees its bright flash, leaving victims in a trance and allowing MiB agents to replace their alien-infested memories with fake ones.

Scientists discovered they could erase specific memories from mice brains a decade ago using beams of light. It seems we're still in the mouse phase.

Ever since Marty McFly hopped on his hoverboard and zoomed across Courthouse Square in "Back to the Future II," kids with a penchant for going fast (and avoiding bullies) have wanted to experience Michael J. Fox's pretend rush. Though rumors that real hoverboards were taken off the market in the 1990s by parent groups were dispelled, there have been recent levitating attempts using magnets, drones, liquid nitrogen, and, most recently, jet turbines.

In McFly's world, the hoverboard existed in 2015, so we're about 10 years behind. Could a cheaper, more practical solution be off the ground in the near future?

Much like the wristwatch in "Clockstoppers," the time control remote from "Click" can pause life. It can rewind and fast-forward it, too. By pressing one of its directional buttons, Adam Sandler's protagonist revisits and cuts through the memorable and tedious moments of his existence (for better and for worse, he'll find).

The closest we've come to achieving that technology is still through the television, holding our spot in a movie for a bathroom break, or jumping past those pesky commercials.

The replicator first appeared in "Star Trek: The Next Generation." The claim was that it could reconstitute inanimate matter by copying the molecular structure of the original material put in its scanner. It could then spit out identical, artificial copies of clothing, wooden and metal structures, and even (slightly diluted) food and drink.

Unlike some of the series' more plausible contraptions, the replicator is about as magical as it gets—even if it logically functions by recycling the ship's excrement as part of its conversion process. Still, at least one expert believes we could have one to try in about a century. In the meantime, we'll continue to enjoy our 3D printers.

Automated, multi-directional highways might not be the most impressive futuristic invention in Steven Spielberg's "Minority Report," but they do eliminate traffic jams. Partially conceived by automotive designer Harald Belker, the movie's driverless cars connect to a Maglev system that allows automobiles to travel vertically in addition to roving over regular highways.

As cars continue to develop into self-driving, -navigating, and -parking machines, it seems inevitable that more complex transportation systems will begin to take shape.

Developed by the villain character Rick Prime, the portal gun is a pistol-shaped gadget that allows its users—namely, Rick and Morty—to travel between different universes and dimensions. Throughout later seasons of "Rick and Morty," we learn the gun is powered by a special fluid Rick calls "Quantum Transport Solution" that is concocted from illegally purchased green-glowing crystals. Naturally, it gets the pair into a load of trouble.

Could we jump through a portal one day? At least one scientific attempt has been made to discover a parallel universe, but no one has broken through yet.

Before the USS Enterprise was the C-57D from "Forbidden Planet." It was the first depiction of a fictional spaceship with faster-than-light speed capabilities. At least from the outside, the spacecraft looked like your typical flying saucer, but many interstellar stories—even this 1956 classic—needed plausible ways for characters to planet and starhop. If a pilot could break the sound barrier, why not have a spaceship soar well past lightspeed?

We know from Albert Einstein that light speed is an absolute limit thanks to his publications on relativity, but nothing should get in the way of a story set in the cosmos.

Out of all the luxurious amenities and items that Cher Horowitz has at her teenage disposal, her digital wardrobe selector might still be the most coveted among "Clueless" fans. Despite functioning on a dial-up desktop, the sartorial gadget lets her comb through her closet's inventory of tops and bottoms before it decides whether her combinations make fashionable sense.

It might not be a replica, but the app Indyx seems to capture Cher's cataloging wizardry the best, hooking up clients with fashion experts who will scroll through your outfits to determine the right look and style. Now it's easier than ever to avoid being "ensembly challenged."

Leave it to Pixar to imagine a world where humans and canines can speak to each other. In addition to balloons lifting an entire house off the ground, "Up" envisioned a world where an electronic collar translates Dug the dog's thoughts and feelings into human words while guiding his guardians, Carl and Russell, on their globetrotting trip.

Thanks to a few hidden cameras and some Pixar magic, it seems writer and actor Bob Peterson tricked a few families with a real golden retriever and a voice-projection collar in 2016. We're still waiting on the real thing.

"What will the future look like?" If you ever got that question as a school assignment, you probably wrote down "flying cars," which can almost single-handedly be attributed to "The Jetsons." The 1960s cartoon family sped out of its home in high-flying style thanks to its shared vehicle, which could fold into a handy suitcase when George Jetson needed to go into the office.

It's hard to imagine this being a particularly safe alternative to today's roads—especially since we're still having trouble with self-driving vehicles. But never say never. George was technically only born two years ago.

The hypersleep chambers in "Alien" or the cryotube—now seen throughout sci-fi movies and TV—came in handy while traveling through the depths of the galaxy. To survive long trips, Ripley and her team must cryogenically freeze themselves inside these locked glass chambers, which suspend their bodily functions and sustain their health—just in time to wake them up for battle against an unwelcome extraterrestrial.

NASA has been developing a cryogenic sleep chamber for its astronauts that lowers their internal temperature so they can dip into hibernation. It's at least the first gambit in achieving interplanetary travel.

When Sharlto Copley's character in Neill Blomkamp's "Elysium" takes a grenade to the face, surgeons rush him to their advanced medical bay. In a matter of seconds, the movie's advanced healing machine scans his body and restores his entire mug to look brand new. That was just one trick the med-bay could pull off. It could also rebuild broken bones and cancerous tissues while checking for other potential diseases, so long as the patient's brain and nervous system remained intact.

A tech this advanced does not exist, but more celebrities and wealthy patients are beginning to opt for full-body MRIs to be aware of future ailments.

Imagine having the power to turn a Pop Tart-style pouch into a McDonald's hamburger meal. In "Spy Kids," Carmen and Juni got to experience that thanks to the rehydrator, an advanced oval microwave capable of turning color-coded square food packets into their actual-sized form and flavor.

In Richard Linklater's rotoscoped "A Scanner Darkly," police officers are all outfitted with "scramble suits," which camouflage them with a rotating mix of appearances and voices. It's a perfect disguise—made up of over a million "fraction representations of men, women, and children"—for undercover law enforcement agents to avoid detection.

Creators have dreamt up many versions of the time machine—the Delorean, the hot tub, and the phone booth—but let's celebrate the one that looks most like a time machine. In the H.G. Wells 2002 adaptation, aptly titled "The Time Machine," scientist Alexander Hartdegen constructs his eponymous whirling invention of brass, wood, and glass that shoots him (accidentally) 800,000 years into the future.

Sadly, scientists don't think time hopping is feasible, even if the laws of physics suggest it might be possible.

Story editing by Carren Jao. Copy editing by Kristen Wegrzyn.