Back to the Future Part 2: Overview

The ongoing reviews are on pause for a very special review of a favorite and formative film, the future scenes of which occur on today’s date.

Release Date: 22 November 1989 (USA)


26 OCT 1985

Doc Brown travels in his flying DeLorean time machine from the future date of 21 SEP 2015 to fetch Marty McFly and his girlfriend Jennifer. When they return to that impossibly far date, Doc puts Jennifer to sleep and enjoins Marty to prevent his son from becoming an accomplice to a crime that ultimately destroys the whole family.

21 SEP 2015

After taking his son’s place and thwarting the bully Griff, Marty seizes an opportunity in the future to purchase an “antique” sports almanac, but Doc throws it away. Griff’s grandfather Biff overhears their conversation and fetches the almanac from the trash.

Before Marty and Doc can get the still-sleeping Jennifer to return to the past, she is apprehended by police and returned to her home where she hides from her future self in a closet. When they leave the time machine to rescue Jennifer, Biff steals the time machine, travels back to 1955 when he was a boy, and uses the almanac to make himself rich.

Back to the Past (1985)

When Doc, Marty, and Jennifer exit the house and return to their own time, the world has changed. Biff is the town’s evil crime and gambling Mogul, married to Marty’s mom, the town is a rough and lawless, and his dad murdered (by Biff).

12 NOV 1955

Together Doc and Marty travel to 1955, where Marty follows Biff to the Enchantment Under the Sea dance, trying to retrieve the almanac while trying to avoid contact with people who might recognize them and keep events meant to happen then on course.

Finally they use the time machine and a hoverboard from 2015 to take the almanac from Biff(1955) and burn the almanac, but lightning strikes the Delorean, sending it away in time. Moments later a mysterious figure delivers a letter from 1885, letting Marty know that Doc was transported there and (as of the writing of the letter) is fine.

Marty rushes to talk to Doc(1955), and the plot pauses until Back to the Future 3.

Flying cars

The DeLorean car plays a significant role in all three films since it is the time travel machine. At the end of the first film, we’’re shown a brief scene (that is repeated at the beginning of the second film) that reveals that the vehicle has been modified so that it flies. Even its modified form it is largely like a car from the period. The driver or pilot manually drives the vehicle with no software assistance or heads-up-display.

I might have strong opinions about the controls of a car being poorly mapped to manage flight, but since this is a hacked-together prototype from materials at hand, it’s less a design problem than a matter of circumstance.

Time circuits (which interface the Flux Capacitor)

BttF_137Time traveling in the DeLorean is accomplished in three steps. In the first, he traveler turns on the “time circuits” using a rocking switch in the central console. Its use is detailed in the original Back to the Future, as below.

In the second, the traveler sets the target month, day, year, hour, and minute using a telephone keypad mounted vertically on the dashboard to the left, and pressing a button below stoplight-colored LEDs on the left, and then with an extra white status indicator below that before some kind of commit button at the bottom.

In the third, you get the DeLorean up to 88 miles per hour and flood the flux capacitor with 1.21 gigawatts of power.

Seems simple.

It’s not… Continue reading

Mr. Fusion Home Energy Reactor


What powers the modified DeLorean is a device called Mr. Fusion, which has the aesthetics and form factor of a household appliance. It is mounted to the back window of the DeLorean. At the beginning of the movie, Doc roots through a nearby garbage can to grab a banana peel and some beer. He rocks the top backwards on its hinge and dumps the items into its cylindrical reservoir, and closes it.

The device has the easy affordances of a consumer device. Doc flips it up, drops some beer and banana peels into a hollow, and snaps it shut. That’s it. There is no lock, no activation, no authorization. The device is hacked by Doc Brown, but you would expect anything outputting 1.21 Gigawatts to have some safety features in the off-the-shelf version.

Presuming it’s meant to power a house or even a car, I do wonder why it’s this size. You might want to have a bigger container to contain as much compost as possible to minimize the times it needs refilling. Of course we know this was a joke about the “Mr. Coffee” appliance available at the time, but if Tesla is eyeballing this as a model, it should take this into consideration.


BttF_013When driving in the sky along with other flying cars that fill the skies in 2015, Doc follows a proscribed path in the sky called a “skyway.” Lanes are distinguished by floating lightposts, which the pilot keeps to his left. It all seems a little chaosy, but so does driving in Mumbai to the outsider, and it works if you know how. The other brilliance of the skyway is that suddenly flying cars make some sense systemically. Before this, I certainly thought of flying cars as personal helicopters, taking you from point to point. But of course that becomes an air traffic control nightmare. Much better to adapt a known system that puts the onus of control to the operators.

Less successful are the road signs. Continue reading

Fueling stations


Fueling stations are up on a raised platform. Cars can ride or land there and approach a central column. A rotating overhead arm maneuvers a liquid fuel dispensing robot into place near the car while a synthesized voice crudely welcomes the driver, delivers a marketing slogan, and announces its actions, i.e. “checking oil,” and “checking landing gear.” Continue reading

Nike MAGs

BttF_026Dr. Brown gives Marty some 21st century clothes in order to blend in. The first of these items are shoes. Marty is surprised to see no laces. To activate them, he pushes his foot into the shoe. When his heel makes contact, the main strap constricts to hold his heel in place. Then the laces constrict to hold the ball of the heel down. Finally, the tongue of the shoe and the “Nike” logo glow.

Yep. Perfect. The activation is natural to the act of putting on the device. The glow acts as a status indicator and symbol. No wonder everyone wanted them.

The Jacket


Dr. Brown gives Marty some 21st century clothes in order to blend in. The first is the pair of Nike MAGs. The other item of clothing Marty must don is a jacket. It has two functions. When Marty first tries it on, the sleeves are nearly twice as long as they ought to be. After complaining that it doesn’t fit, Dr. Brown reaches and pinches a blinking and beeping red LED at the base of the jacket’’s zipper. In response, the sleeves retract to a proper length, the pocket flaps shrink, and the epaulettes flatten out as a synthesized voice states, ““Adjusting fit.”

Continue reading



Doc Brown uses some specialized binoculars to verify that Marty’ Jr. is at the scene according to plan. He flips them open and puts his eyes up to them. When we see his view, a reticle of green corners is placed around the closest individual in view. In the lower right hand corner are three measurements, “DISTgamma, and “XYZ.” These numbers change continuously. A small pair of graphics at the bottom illustrate whether the reticle is to left or right of center.


As discussed in Chapter 8 of Make It So, augmented reality systems like this can have several awarenesses, and this has some sensor display and people awareness. I’m not sure what use the sensor data is to Doc, and the people detector seems unable to track a single individual consistently.


So, a throwaway interface that doesn’t help much beyond looking gee-whiz(1989).


When officers Foley and Reese find the sleeping Jennifer, they thumbprint her on a wireless handheld device, and Officer Foley looks up the young girl’s information. Looking at the screen she retrieves Jennifer’(2015)’s address and age.


Thumbprint is a fine unimodal authenticator, but much better is multimodal biometric or multifactor authenticator to be certain of identity.