Time circuits (which interface the Flux Capacitor)

21 Oct 2015 by Christopher Noessel

Time 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…

Rocker switch?

Note that the rocker switch angles down to a nearly 45 degree angle in the on position. One of the worst thing that could happen is for that thing to get accidentally turned off at the wrong time, I imagine. (Back to the Future 4: Lost in Somewhen?) The 45 degree angle makes an accidental activation unlikely, but the T-shaped handle means it could catch on a sleeve or bag handle or something. There are more secure safety switches, but I also wonder if it would be smarter to use the Fake Off mode that most electronics run in today, where they’re never really off, but look off, just waiting for user interaction to spring to life. With a Mr. Fusion on board, I presume powering it isn’t that much of a problem.

Good disambiguation

Note that the pad only has numbers. But Doc uses the military and European standard date format

[day of month] [month] [year]

which might confuse another user, i.e. Marty, entering the stupid USA standard

[month] [day of month] [year]

Though preventing errors is preferable, at least Doc helps Marty recognize errors by displaying the month in 3-character text format, which would help Marty realize if he’d accidentally put in 10 September instead of 09 October.

Bad disambiguation

Note that doc is traveling to 4:29 in the afternoon, and the display has a tiny LED A.M./P.M. indicator. Better is the less ambiguous military time. Sure, audiences might have been confused, but using a 24-hour clock would have been less ambiguous for diegetic users, you could eliminate the AM/PM indicator, and Doc could use the existing number pad for entry without having to either add an “AM” and “PM” button (missing from the console), or doing some annoying “press 1 for AM or 2 for PM now” IVR thing.

While we’re on time disambiguation, what, uh, time zone is this? Did doc only ever plan to fly in and around Hill Valley? It might have been keyed to the Prime Meridian, or to Pacific Time, but if so it would have been very useful to have it marked as such. If not, it should display the current time zone and provide a means to change it. Somehow. With that number pad. (Or more controls.)

Bad input constraint and recovery

It’s wholly possible to enter a day-of-month or month of “99,” which is nonsensical given the Gregorian calendar that we use today. How does the system handle this? A mod function? There’s no clue, but the unconstrained inputs would allow it.

Farther travel?

As the Long Now Foundation reminds us, a four-digit date is really short-sighted. So Doc didn’t want to travel to 10,000 C.E. and see if Zager & Evans were right? And what if he wanted to go meet Amenhotep? How does he specify 1526 B.C.E.? It seems unduly constrained.

Misleading mapping

I don’t know what those LEDs to the left of the input panel do, but I can tell they’re poorly mapped. The colors go, from top to bottom: red, yellow, and green, like a stoplight. Then there’s the extra white LED below that maps to nothing. But the LED colors on the display go from top to bottom red for destination, green for present, yellow for last time departed. Better mapping would have these two agree, or distinct color schemes.

Missing controls

In 1985 dialing a telephone number worked much like the dial-a-date seen here. Punch a sequence of numbers and the system runs with the input. But instant-input systems need a way to correct errors; either the ability to review and correct the input, or to abort the input altogether and start over.

Phone users from back then will recall it was entirely possible to mistype a digit and dial a wrong number. You’d be connected to a stranger who had no idea who this “Marty” you wanted was. This is more serious in the DeLorean than on a phone, as it drops the user into circumstances potentially much more dire, from which there might be no recovery. What would happen if they had accidentally wound up in 21 October 1015? Wholly different story. Is Biff distantly related to Cnut the Great?

Doc might be able to review the input on the display before getting up to speed, but there’s no obvious control for aborting input so far and starting over. (What if he has skipped a digit instead of mistyping one?) A simple delete button would help him correct mistyped digits. Even if he mistyped the first one and only realized it at the end, it wouldn’t be too burdensome to press delete the handful of times.

Rich preview

How does the system confirm for Doc that he’s entered the right date he intended to? On one level, sure, the 7-segment LED output is clear and unambiguous. It’s a nice discrete number. But of course 7-segment 1989 isn’t that easy to distinguish from 1898 when you’re distracted. Better would be to give a preview of the meaning of the choices entered (but not yet enacted) by the user. If there was a video screen in the car, then maybe it could show scenes from old Westerns with the label “Headed to 1898: The Old West.” You could even do it with the cars’ speakers and an audio soundscape if a screen wouldn’t work for space or distraction reasons.

Security

As noted in the overview, Biff(2015) gets into the car to make off for 1955 early in the film. I can’t quite figure out how he was able to figure out turning on the time circuit and that the 88MPH was a target speed, but he did. (Seriously, looking for fan theories here.) Of course Doc might have designed everything to be perfectly understandable for Marty, but that’s no excuse to avoid authenticating the user, since Doc is so panicked about the consequences of the time travel that he’s doing all the times. [sic]

Main Power Board

12 Aug 2015 by claytonbeese

To restore the power that Nedry foolishly shut down (and thereby regain a technological advantage over the dinosaurs), Dr. Sattler must head into the utility bunker that routes power to different parts of the park.

Once she is there Hammond, back in the Visitors Center, communicates to her via two-way radio that operating it is a two part process: Manually providing a charge to the main panel, and then closing each of the breakers.

The Main Panel

To restore a charge to the main panel, she manually cranks a paddle (like a kinetic-powered watch, radio, or flashlight), then firmly pushes a green button labeled “Push to Close”. We hear a heavy click inside the panel as the switch flips something, and then the lights on the Breaker Panel list light up green.

Now that she has built up a charge in the circuit, she has to turn on each of the breakers one by one.

The Breakers

Each individual circuit has a dedicated button to open/close it. Each is switched with a simple illuminated button protected by a heavy, clear pushbutton cover that has to be opened manually.

Green indicates that the circuit has tripped, and power is not flowing to that part of the park. Red means that the circuit is closed and live. Slowly, one by one, Dr. Sattler flips the cover and presses the red button for each part of the breaker panel. These switches are clearly labeled as HERBIVORE FEEDING COMPOUND, or VISITORS CNTR.

As she flips each circuit on, red lights behind the label turn on.

The Circuit Breakers

The pushbutton covers do a good job of protecting against inadvertent flips, but could be made better by having hinges that close them automatically. It is unlikely that someone would accidentally push one of the buttons, but the high-risk nature of the panel begs for more protection. Spring hinges would also make closing the panel up after service quicker.

A second consideration is an emergency scenario: there is no obvious way to flip all the circuits off at once, or turn them all back on quickly. Here, all that extra time is super dramatic since it happens to save Dr. Grant and the kids, hanging at this same moment as they are from the unpowered electrified fence. But if someone was trying to reactivate the park quickly, to say, save the visitors from being eaten, this circuit-by-circuit method takes a surprising amount of time.

Labeling & Color

The labeling here is good, but could still be better. The lights are the first thing to draw attention, but it’s actually the charging panel that needs to be tended to first. A good flowchart of how a person is supposed to use the panel would be an effective addition; as would a map showing which labeled breaker leads to which area of the park.

At first the red-and-green colors are backwards, but it turns out a longstanding standard within electrical engineering uses red to indicate “shock hazard” rather than “operating normally”, so this color coding is actually OK. But it might be more effective to only light up the breakers’ labels when power is actually flowing to them. For someone not experienced with the interface or electrical engineering conventions, having a few of the breakers active and a few flipped could be extremely confusing. Are the lit ones active? Inactive? Is power flowing to the panels with lights?

This panel would be a solid candidate for usability testing.

Velociraptor Lock

9 Jun 2015 by claytonbeese

The velociraptor pen is a concrete pit, topped with high-powered electric fences. There are two ways into the pen: a hole at the top of the pen for feeding, and a large armored door at ground level for moving ‘raptors in and out. This armored door has the first interface seen in the film, the velociraptor lock.

Velociraptors are brought from breeding grounds within the park to a secure facility in a large, heavily armored crate. Large, colored-light indicators beside the door indicate whether the armored cages are properly aligned with the door. The light itself goes from red when the cage is being moved, to yellow when the cage is properly aligned and getting close to the door, to green when the cage is properly aligned and snug against the concrete walls of the velociraptor pen. There is also a loud ‘clang’ as the light turns to green. It isn’t clear if this is an audio indicator from the pen itself, the cage hitting the concrete wall, or locks slamming into place; but if that audio cue wasn’t there, you’d want something like it since the price for getting that wrong is quite high.

The complete interface consists of four parts (kind of, read on): The lights, the door, the lock, and the safety. More on each below.

1. The Deceiving Lights

The lights are the most obvious part of the system (aside from the cage and pen). Everyone who is watching the cage also has a clear view of the lights – there is an identical set on the other side of the cage for the other half of the safety/moving crew.

2. The Door

The Velociraptor pen’s door is perfectly shaped to accept the heavily armored cage, and is equipped with a rail system to keep the cage aligned properly with the door. Though it takes eight workers to move the cage, they appear to be able to push the cage reasonably easily. When the light turns green, the workers move back to allow the gate to be manually raised on the cage, letting the caged velociraptor escape into the pen.

3. The “Lock”

JurassicPark_velociraptorlock01 — Or, lack thereof…

Every indication (the lineup of the cage, the green lights, and the heavy metallic ‘clang’) gives the feeling of a secure mating between the cage and the pen. All of the workers relax, as if they’re sure they’re as safe as they can be. But you can be certain, this is a false sense of security.

As soon as the velociraptor decides to test the lock, it is able to push the cage away from the pen wall. The light near the door instantly changes from green back to red.

Narratively, this underscores some of the risks of the park, i.e. that it’s cheaply engineered despite appearances, and extra-diegetically sets the audience on edge since it’s not sure what it can trust. But, for us in the real world, given the many indications that the system was safe, it should have actually been safe.

4. The Safety

When the clever velociraptor knocks the cage back, a worker falls in and becomes an unscheduled snack. Attendant workers try to help using…

The Cattle Prods

When the gate master falls and gets snatched by the velociraptor in the cage, workers immediately rush in and start hitting her with cattle prods. There are at least six prods being used, possibly more.

Since this is the first line of backup defense, the cattleprods should have been iterated until they actually deterred the ‘raptors. Clearly, effort went into making the perimeter defenses secure against the larger dinosaurs. The same effort should have gone into making the cattle prods effective against velociraptors.

Design for Success

The Velociraptor pen door seems custom-designed for serious failure: No hard locks to keep the cage in place, horrible sight-lines, and manual controls in places that make it dangerous for workers. Even the solid feedback system only adds to the danger. It lulls the workers into thinking the system is safe.

Most, if not all, of these issues would be solved by a simple physical locking device on the cage. Something to hold the cage in place while the doors are open would maintain a secure pen and keep everyone outside safe. It would also eliminate the need for most of the support crew, who only end up getting in each other’s way.

To add to the safety, the park designers should have paid more attention to where people would be standing during the transfer process. The armed guards (theoretically there to be a second line of defense), are placed in such a way that only a few of them are able to effectively fire. Other guards on scene would have to fire past their fellow guards.

Presumably, this is why the armed guards don’t actually fire at the ‘raptor when Muldoon shouts to “Shoot her! Shooooooot her!!”

Keep the feedback…

The feedback systems of the cage are remarkably successful, for a placebo. The lights, sounds, and placement keep the workers and audience calm right up until things go horribly wrong. With the addition of Muldoon’s organizational skill and animal handling skills, the feedback system is worth taking notes on.

…but make it mean something

The velociraptor pen was designed to tell the workers what state it was in, but not to actually keep them safe. Muldoon’s precautions try to make up for the system’s failures, but only add to the problems as the workers trip over each other.

Containment unit

31 Oct 2014 by Christopher Noessel

With a ghost ensconced in a trap, the next step in ghostbusting is to transfer the trap to a containment unit. Let’s look at the interaction.

The containment unit is a large device built into a wall of the old firehouse that serves as the Ghostbusters headquarters. It’s painted a fire-truck red and has two colored bulbs above it. As they approach, the green bulb is lit. It’s got a number of buttons, levers, and cables extending into it. Fortunately for purposes of discussion, Stantz has to explain it to their new employee Winston Zeddmore, and I can just quote him.

“This is where we store all the vapors, entities, and slimers that we trap. Very simple, really. Loaded trap here. Unlock the system…” He grabs the red door lever and cranks it counterclockwise 90 degrees and lowers the door to reveal a slot for the trap.

“Insert the trap,” he continues, and a sucking sound is heard and the green lightbulb goes off and the red lightbulb turns on.

Then Stanz pulls the trap out of the slot and is able to, as he explains, “Release. Close. Lock the system.” (Which he does with the lever handle.)

Next, he presses the buttons on the front of the device, starting with the top red one and continuing with the second below yellow, explaining, “Set your entry grid. Neutronize your field…” Then he grabs the red lever on the right-hand size and pushes it down. In response, the lowest push button lights up green, the red bulb above turns off, and the green bulb illuminates once again.

Stantz concludes, “When the light is green, the trap is clean. The ghost is incarcerated here in our custom-made storage facility.”

The interaction here is all based on the unkonwn ghostbusting technology, but it certainly feels very 1.0, very made-by-engineers, which is completely appropriate to the film. There’s also that nice rhyming mnemonic to remember the meaning of the colored bulbs, which helps Zeddmore immediately remember it. And course with the red paint and thick plates, it feels really secure and conveys a sense of pith and importance. Still, if they had a designer consulting, that designer would most likely tell them talk about a few aspects of the workflow.

Consolidate

First, why, if there’s no breakpoint between the entry grid and the field neutronizer, can’t those two be consolidated into a single button? A gridtronizer? While we’re on the buttons, why is that third one looks like a button but acts just like a light? If it’s not meant to be pressed, let’s make it an indicator light, like we see on the trap.

Similarly, why do they have to press that last lever and wait for the green light? I get that a variety of controls feels better to convey a complicated technology that’s been hacked together, and that would be appropriate for a user to understand as well, but it seems error-prone and unnecessary. Better would be another pushbutton that would stay depressed until the unit was doing whatever it was doing behind the scenes, and then release when it was done. It could even be consolidated with the gridtronizer.

Simplify

But while we’re including automation in the process, why would the ghostbuster have to press anything at all? If the unit can detect when a ghost has been sucked in (which it does) then why can’t it do all the other steps automatically? I know, it would be less juicy for the audience’s sense of ghostbusting technological complexity, but for the “real world,” such things should be fully assistive:

Insert trap (which gets locked in place)
Watch the machine’s lights indicating its four steps
Remove unlocked trap.

You might think for efficiency to have the trap removed immediately, but you really want the Ghostbuster’s attention on the system in case something goes wrong. Similar to the way ATMs/bancomats hold on to your card through a transaction.

Lastly, there should be some sense of what’s contained. In this scene there’s just Slimer in there, but as business picks up, it gets so jammed full that when EPA representative Peck recklessly shuts it down, it…you know…explodes with ghosts. Would a sense of the contents have helped provide him with a sense of the contents, and therefore the danger? A counter, a gauge, a window into the space, a “virtual window” of closed-circuit television showing inside the unit*, or a playback showing helmet-cam video of the ghosts as they’re being captured—would all help to convey that, Mr. Peck, you do not want to eff with this machine.

*IMDB trivia for the movie says this was originally included in the script but was too depressing to visualize so it was cut. But hey, if it’s depressing, maybe that would help its users consider the ethics of the situation. (Once again, thank you, @cracked, and RIP.)

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