It's November 2019 and Los Angeles is in a state of urban decay. The population has dwindled, and humans face a new threat from manufactured biological robots gone rogue... Back in 1982, this is how Blade Runner director Ridley Scott imagined the world would be.
Thirty-seven years after the film was released, how accurate were its predictions about how technology would play a bigger role in our lives? Here are some of the things the film got right, and others where it was way off the mark.
1. Robots are much smarter
Set in November 2019, the original film follows Rick Deckard, whose job as a police "blade runner" is to hunt and kill bio-engineered androids known as replicants. So-called Nexus 6 replicants are described as "virtually identical to a human" and "at least equal in intelligence to the genetic engineers who created them".
When a group arrives on Earth to try to extend their four-year lifespan, Deckard is summoned to eliminate them. Today's mechanical robots do not look as lifelike as Zhora, Pris, Roy and Leon.
Even when they take human form, you are more likely to experience pre-scripted jokes and a clunky conversation, rather than the self-aware reflections on mortality and talk of "tears in the rain" found in the movie. But AI is getting smarter.
Just this week, Google's sister-company DeepMind said it had created the first "agents" that had reached the top league of Starcraft 2, one of the most popular esport video games.
2. Video calling is mainstream
Deckard's video call to replicant Rachael is an example of where today's tech has overtaken that shown in the film. Video calling actually started as early as the 1920s, when the boss of telecoms giant AT&T spoke to former US president Herbert Hoover using a TV signal and phone line. But it was not until Skype launched in 2003 that it started to become commonplace.
Today, video calls are made in a variety of ways, including Apple's FaceTime, Google's Duo and Facebook's WhatsApp - all of which are capable of delivering a higher-resolution image to smartphones than the bulky booth could display in the film. And unlike Blade Runner, it does not cost $1.25 (95p) to make a short call.
3. Homes are also getting smarter. Virtual assistants feature prominently in the film. As Deckard returns home, he's asked for his "voice print identification" as he steps into the lift. "Deckard 97" he replies while punching the same numbers into a keypad. "Thank you", a female voice responds.
In the real world, Amazon's Alexa and Google's Assistant can identify us by our voice patterns and tailor their behaviour accordingly. Eldon Tyrell, founder of the Tyrell Corporation which makes replicants, also uses a virtual assistant. But his preference for candlelight rather than internet-connected bulbs at home would make it impossible to enjoy the kind of automated lighting routines offered by today's smart home systems. Switching to security, Deckard uses a smart key to open his front door.
Norwegian Tor Sørnes invented the first recordable keycard door lock in the 1970s. Today, these cards are used by hotels around the world. But the latest wave of smart locks are more likely to require a wireless signal from your mobile or a biometric reading to control entry.
4. Lie detectors are still used
Central to the film's plot is the Voight-Kampff machine, which is used by blade runners to separate humans from robots, using questions designed to provoke an emotional response. It's an elaborate machine which measures bodily functions, such as contractions of the eye's iris.
While it looks very different to the first polygraph machine of 1921, UK police forces still use them, particularly to investigate sex offences. However, their reliability has been disputed. A lie detector test is not admissible in the UK as evidence.
US company Converus uses similar iris technology to detect lies.
5. The planet is changing
Dim lights and dark skies portray Los Angeles in 2019 as a city that has been damaged by industrial pollution, forcing many to flee. "There's no housing shortage around here," genetic designer JF Sebastian tells replicant Pris as she visits his home. "Plenty of room for everyone."
In reality, Los Angeles gets ever more crowded by the year. But fears about climate change have prompted California to try to lead the way in cutting carbon emissions.
6. Blade Runner ignores the Instagram generation
Photographs play a central role in the film, both as evidence and as a way for Rachael to convince herself she is human. Deckard analyses several physical Polaroid pictures for clues on how to find other replicants. In reality, Polaroid cameras still exist, but they are now more of a novelty than the smartphones we regularly use to take snaps.
It is more likely we would see today's Deckard trawling through the replicants' Instagram or Facebook accounts for clues. And Rachael's sole photograph with her mother might be replaced by several selfies.
Today computational photography is becoming the norm, helping our phones take incredible low-light pictures, and automatically blur the background of our portrait shots. But the Esper machine, which Deckard uses to find clues by zooming in on different things within photos, remains ahead of its time. It enables him to see objects and people from different angles, and items which were not previously visible.
AI researchers are working on software that can create interactive 3D views from a single 2D source image, but it's likely to be many more years to come before Photoshop gets the feature.
Atari is another big brand in the film. The video game pioneer was huge in arcades and homes in the 1970s and 1980s.
And while it has since ceded ground to PlayStations, Xboxes and Switches, there are plans to breathe fresh life into the brand.
A new Atari VCS throwback console attracted more than $2m (£1.54m) in pre-orders last year - but doubts have been raised as to whether it will ship by early 2020 as planned.
7. Flying cars aren't mainstream... yet
Many films have depicted flying cars in the future. And while lots of progress has been made on the concept of flying cars , both in Japan and the United States, there are none on the roads (or in the sky) yet.
The inside of Blade Runner's flying cars are full of gadgets, and look similar to the cockpit of a plane.
But it's notable that those inside are not strapped in - the film was made before California introduced mandatory seat belt laws.
8. Most hairdryers still look like hairdryers
In one scene, replicant Zhora dries her hair in what looks like an upside-down goldfish bowl: it dries in seconds. While ionic technology and ceramic heating elements help today's hairdryers to do a faster job, even a £300 Dyson model takes minutes rather than seconds to finish.
(Source: BBC News)
