Staff of the Living Tribunal

This staff appears to be made of wood and is approximately a meter long when in its normal form. When activated by Mordo it has several powers. With a strong pull on both ends, the staff expands into a jointed energy nunchaku. It can also extend to an even greater length like a bullwhip. When it impacts a solid object such as a floor, it seems to release a crack of loud energy. Too bad we only ever see it in demo mode.

How might this work as technology?

The staff is composed of concentric rings within rings of material similar to a collapsing travel cup. This allows the device to expand and contract in length. The handle would likely contain the artificial intelligence and a power source that activates when Mordo gives it a gestural command, or if we’re thinking far future, a mental one. There might also be an additional control for energy discharge.

In the movie, sadly, Mordo does not use the Staff to its best effect, especially when Kaecilius returns to the New York sanctum. Mordo could easily disrupt the spell being cast by the disciples using the staff like a whip, but instead he leaps off the balcony to physically attack them. Dude, you’re the franchise’s next Big Bad? But let’s put down the character’s missteps to look at the interface.

Mode switching and inline meta-signals

Any time you design a thing with modes, you have to design the state changes between those modes. Let’s look at how Mordo moves between staff, nunchaku, and whip in this short demonstration scene.

To go from staff to nunchaku, Mordo pulls it apart. It’s now in a dangerous state, so is there any authentication or safety switch here? It could be there, but all passive via contact sensors, which would be the best so it could be activated in a hurry. The film doesn’t give us any clue, really, so that’s an open question.

How does it know to go from nunchaku to whip? It sure would be crappy to bet on a disabling thwack against your opponent only to find it lazily draping over a shoulder instead. (Pere Perez might have advanced ideas, given his ideas on light saber tactics.) Again, this state change could be passive, detecting in real time the subtle gestural differences in a distal snap, which a bullwhip would need, and lateral force, which sets the nunchaku spinning, and adjust between the two accordingly. Gestural and predictive technologies are not cinemagenic, so let’s give it the benefit of the doubt and say that’s what’s happening.

A last mode is After Mordo cracks it against the ground, it retracts back to Staff form. This is the hardest one to buy. Certainly it’s a most dramatic ending for Mordo’s demonstration. But does it snap back automatically after it strikes a surface? Automation is not always the answer. Deliberate control would mean Mordo doesn’t have to waste time undoing unwanted automatic actions.

Critical systems must be extremely confident in their interpretations before automation is the right choice.

It might be that this particular gesture is a retraction signal, but how the Staff distinguishes this from a mid-combat strike is tricky. It would have to have sophisticated situational awareness to know the difference, and it doesn’t display this. Better backworlding would point at some subtle gestural signal from Mordo. A double-tightening of his grip, maybe. Or even a double-slight-release of his grip, since that’s something he’s quite unlikely to do in combat.

This is a broad pattern for designers to remember. Inline control signals should be simple-to-provide, but unlikely to occur in literal use. Imagine if the Winter Soldier’s Trigger Phrase wasn’t “Longing, rusted, 17, daybreak, furnace, 9, benign, homecoming, 1, freight car” but instead was the word “the.” He’d be berserking every few seconds. Unworkable. So, if you were designing the Staff’s retraction command gesture, you’d have to pick something he could remember and perform easily, and that would be difficult to accidentally provide.

If Mordo has the staff in the next film, I hope the control modes are clearer and of course well-designed.

Door Bomb and Safety Catches

Johnny leaves the airport by taxi, ending up in a disreputable part of town. During his ride we see another video phone call with a different interface, and the first brief appearance of some high tech binoculars. I’ll return to these later, for the moment skipping ahead to the last of the relatively simple and single-use physical gadgets.

Johnny finds the people he is supposed to meet in a deserted building but, as events are not proceeding as planned, he attaches another black box with glowing red status light to the outside of the door as he enters. Although it looks like the motion detector we saw earlier, this is a bomb.


This is indeed a very bad neighbourhood of Newark. Inside are the same Yakuza from Beijing, who plan to remove Johnny’s head. There is a brief fight, which ends when Johnny uses his watch to detonate the bomb. It isn’t clear whether he pushes or rotates some control, but it is a single quick action. Continue reading

Dat glaive: Projectile gestures

TRIGGER WARNING: IF YOU ARE PRONE TO SEIZURES, this is not the post for you. In fact, you can just read the text and be quit of it. The more neurologically daring of you can press “MORE,” but you have been forewarned.

If the first use of Loki’s glaive is as a melée weapon, the second use is of a projectile weapon. Loki primes it, it glows fiercely blue-white, and then he fires it with usually-deadly accuracy to the sorrow of his foes.

This blog is not interested in the details of the projectile, but what is interesting is the interface by which he primes and fires it. How does he do it? Let’s look. He fires the thing 8 times over the course of the movie. What do we see there? Continue reading

Eve’s Gun


For personal security during her expeditions on Earth, Eve is equipped with a powerful energy weapon in her right arm. Her gun has a variable power setting, and is shown firing blasts between “Melt that small rock” and “Mushroom Cloud visible from several miles away”


After each shot, the weapon is shown charging up before it is ready to fire again. This status is displayed by three small yellow lights on the exterior, as well as a low-audible charging whine. Smaller blasts appear to use less energy than large blasts, since the recharge cycle is shorter or longer depending on the damage caused.


On the Axiom, Eve’s weapon is removed during her service check-up and tested separately from her other systems. It is shown recharging without firing, implying an internal safety or energy shunt in case the weapon needs to be discharged without firing.

While detached, Wall-E manages to grab the gun away from the maintenance equipment. Through an unseen switch, Wall-E then accidentally fires the charged weapon. This shot destroys the systems keeping the broken robots in the Axiom’s repair ward secured and restrained.

Awesome but Irresponsible

I am assuming here that BNL has a serious need for a weapon of Eve’s strength. Good reasons for this are:

  • They have no idea what possible threats may still lurk on Earth (a possible radioactive wasteland), or
  • They are worried about looters, or
  • They are protecting their investment in Eve from any residual civilization that may see a giant dropship (See the ARV) as a threat.

In any of those cases, Eve would have to defend herself until more Eve units or the ARV could arrive as backup.

Given that the need exists, the weapon should protect Eve and the Axiom. It fails to do this because of its flawed activation (firing when it wasn’t intended). The accidental firing scheme is an anti-pattern that shouldn’t be allowed into the design.


The only lucky part about Wall-E’s mistake is that he doesn’t manage to completely destroy the entire repair ward. Eve’s gun is shown having the power to do just that, but Wall-E fires the weapon on a lower power setting than full blast. Whatever the reason for the accidental shot, Wall-E should never have been able to fire the weapon in that situation.

First, Wall-E was holding the gun awkwardly. It was designed to be attached at Eve’s shoulder and float via a technology we haven’t invented yet. From other screens shown, there were no physical buttons or connection points. This means that the button Wall-E hits to fire the gun is either pressure sensitive or location sensitive. Either way, Wall-E was handling the weapon unsafely, and it should not have fired.


Second, the gun is nowhere near (relatively speaking) Eve when Wall-E fires. She had no control over it, shown by her very cautious approach and “wait a minute” gestures to Wall-E. Since it was not connected to her or the Axiom, the weapon should not be active.


Third, they were in the “repair ward”, which implies that the ship knows that anything inside that area may be broken and do something wildly unpredictable. We see broken styling machines going haywire, tennis ball servers firing non-stop, and an umbrella that opens involuntarily. Any robot that could be dangerous to the Axiom was locked in a space where they couldn’t do harm. Everything was safely locked down except Eve’s gun. The repair ward was too sensitive an area to allow the weapon to be active.

In short:

  1. Unsafe handling
  2. Unauthorized user
  3. Extremely sensitive area

Any one of those three should have kept Eve’s gun from firing.

Automatic Safeties

Eve’s gun should have been locked down the moment she arrived on the Axiom through the gun’s location aware internal safeties, and exterior signals broadcast by the Axiom. Barring that, the gun should have locked itself down and discharged safely the moment it was disconnected from either Eve or the maintenance equipment.

A Possible Backup?

There is a rationale for having a free-form weapon like this: as a backup system for human crew accompanying an Eve probe during an expedition. In a situation where the Eve pod was damaged, or when humans had to take control, the gun would be detachable and wielded by a senior officer.

Still, given that it can create mushroom clouds, it feels grossly irresponsible.

In a “fallback” mode, a simple digital totem (such as biometrics or an RFID chip) could tie the human wielder to the weapon, and make sure that the gun was used only by authorized personnel. (Notably Wall-E is not an authorized wielder.) By tying the safety trigger to the person using the weapon, or to a specific action like the physical safeties on today’s firearms, the gun would prevent someone who is untrained in its operation from using it.

If something this powerful is required for exploration and protection, it should protect its user in all reasonable situations. While we can expect Eve to understand the danger and capabilities of her weapon, we cannot assume the same of anyone else who might come into contact with it. Physical safeties, removal of easy to press external buttons, and proper handling would protect everyone involved in the Axiom exploration team.

Section No6’s crappy sniper tech



Section 6 sends helicopters to assassinate Kunasagi and her team before they can learn the truth about Project 2501. We get a brief glimpse of the snipers, who wear full-immersion helmets with a large lens to the front of one side, connected by thick cables to ports in the roof of the helicopter. The snipers have their hands on long barrel rifles mounted to posts. In these helmets they have full audio access to a command and control center that gives orders and recieves confirmations.


The helmets feature fully immersive displays that can show abstract data, such as the profiles and portraits of their targets.



These helmets also provide the snipers an augmented reality display that grants high powered magnification views overlaid with complex reticles for targeting. The reticles feature a spiraling indicator of "gyroscopic stabilization" and a red dot that appears in the crosshairs when the target has been held for a full second. The reticles do not provide any "layman" information in text, but rely solely on simple shapes that a well-trained sniper can see rather than read. The whole system has the ability to suppress the cardiovascular interference of the snipers, though no details are given as to how.

These features seem provocative, and a pretty sweet setup for a sniper: heightened vision, supression of interference, aiming guides, and signals indicating a key status. But then, we see a camera on the bottom of the helicopter, mounted with actuators that allow it to move with a high (though not full) freedom of movement and precision. What’s this there for? It wouldn’t make sense for the snipers to be using it to aim. Their eyes are in the direction of their weapons.


This could be used for general surveillance of course, but the collection of technologies that we see here raise the question: If Section 9 has the technology to precisely-control a camera, why doesn’t it apply that to the barrel of the weapon? And if it has the technology to know when the weapon is aimed at its target (showing a red dot) why does it let humans do the targeting?

Of course you want a human to make the choice to pull a trigger/activate a weapon, because we should not leave such a terrible, ethical, and deadly decision to an algorithm, but the other activities of targeting could clearly be handled, and handled better, by technology.

This again illustrates a problem that sci-fi has had with tech, one we saw in Section 6’s security details: How are heroes heroic if the machines can do the hard work? This interface retreats to simple augmentation rather than an agentive solution to bypass the conflict. Real-world designers will have to answer it more directly.

R-3000 “Spider tank” vision


Section 6 stations a spider tank, hidden under thermoptic camouflage, to guard Project 2501. When Kunasagi confronts the tank, we see a glimpse of the video feed from its creepy, metal, recessed eye. This view is a screen green image, overlaid with two reticles. The larger one with radial ticks shows where the weapon is pointing while the smaller one tracks the target.

I have often used the discrepancy between a weapon- and target-reticle to point out how far behind Hollywood is on the notion of agentive systems in the real world, but for the spider tank it’s very appropriate.The image processing is likely to be much faster than the actuators controlling the tank’s position and orientation. The two reticles illustrate what the tank’s AI is working on. This said, I cannot work out why there is only one weapon reticle when the tank has two barrels that move independently.



When the spider tank expends all of its ammunition, Kunasagi activates her thermoptic camouflage, and the tank begins to search for her. It switches from its protected white camera to a big-lens blue camera. On its processing screen, the targeting reticle disappears, and a smaller reticle appears with concentric, blinking white arcs. As Kunasagi strains to wrench open plating on the tank, her camouflage is compromised, allowing the tank to focus on her (though curiously, not to do anything like try and shake her off or slam her into the wall or something). As its confidence grows, more arcs appear, become thicker, and circle the center, indicating its confidence.

The amount of information on the augmentation layer is arbitrary, since it’s a machine using it and there are certainly other processes going on than what is visualized. If this was for a human user, there might be more or less augmentation necessary, depending on the amount of training they have and the goal awareness of the system. Certainly an actual crosshairs in the weapon reticle would help aim it very precisely.


The Ultimate Weapon


The most interesting interface in the film belongs to the Ultimate Weapon, because it raises such unusual challenges to interface design.

The Design Challenge

According to the movie, the Ultimate Evil arrives every 5000 years, and this is the only time the weapon needs to be fired. (Its prior firing would be around 2737 B.C.E., and if it was on Earth before then, in prehistory.) Its designers must ensure that it will be usable to users separated by around 250 (human) generations. Given such an expanse of time, how can a designer ensure that any necessary inputs will be available between potential uses? What materials will survive that long to ensure structural and functional viability? What written instructions can survive the vast changes in language and cultural contexts? How can you ensure that spoken instructions or principles will be passed down accurately from generation to generation? Presuming some lossy transmission, what clues can you give in the interface itself as to the intended use?

Mondoshawan physiology

Fortunately, the Mondoshawan physiology is not a substantial problem. In their suits they are still similarly-sized, bilateral, upright bipeds with a head where sensory organs are clustered at the top, and, emerging from the tops of their torsos, prehensile arms at the end of which are manipulator digits. This solves a great deal of what could be difficult interspecies issues. Imagine, for contrast, trying to design an interface usable by intelligent versions of both butterflies and cephalopods. Not easy. But an interface for two humanoid species: Much less difficult.

How to ensure the interface material lasts?

Certainly, the system must maintain some physical integrity over time. Passing over the creative license of “advanced alien technologies,” we see that the material for the weapon is quite-long lasting, i.e. stone and in the case of the key, metal. Additionally, the weapon is kept in a temple in the desert, a non-volatile environment suited to preserving such materials.


There are materials for the stones that could last longer and be more resistant to damage, like metal or industrial ceramics, but we do not know anything about the provenance of the weapon, and whether such materials were available.

How to hide the weapon from malefactors?

In the words of Cornelius, an evil person could stand on the platform and activate the weapon to “turn light to dark.” No one wants that to happen. The Mondoshawans hide the weapon in the Egyptian temple, and take pains to carefully conceal the presence of the door to the weapon room and its keyhole. Ordinarily Mondoshawans keep the key to the door of the room which houses the weapon to themselves offworld, but when they take the stones for protection, they leave the key with a member of a sect that worships the weapon, ensuring that the key is passed down through the generations along with the weapon’s instructions.

How to ensure the instructions persist?

Even with durable materials, if the use of the weapon isn’’t so completely intuitive as to be automatic, the instructions on how to activate it must endure transmission through time, across the lives of generations of people (and Mondoshawans). In this case, the instruction set is fairly simple; one must have access to “the” five elements for the weapon to work. Four are the familiar classical alchemical elements of earth, air, fire, and water. These are represented in the movie by four patterns of lines. The lines have subtle variations that reflect physical properties of that element. Earth was flat horizontal lines. Water was wavy horizontal lines at the base. Air was wavy horizontal lines at the top. Fire was vertical wavy lines.

The simplicity, replicability, and memetic nature of this part of the instruction set is demonstrated as we see the symbol repeated in a number of places: on the walls of the pyramid, on the sides of the stones, on the pedestals to which each stone fits, on Cornelius’’ belt buckle, and as a mark on Leeloo’’s skin. Had these symbols been more complex in nature, there would have been more risk that they would have shifted and evolved, like language does, beyond recognition and therefore use as a clue to the weapon’s function.

The instructions are also kept alive through the ages via myth and religious fervor. The characters Cornelius and David belong to a sect devoted to the Ultimate Weapon. This is clever cultural design. Humans have historically demonstrated a desire to worship, and the Mondoshawans have taken advantage of this, providing the Ultimate Weapon a group of people wholly dedicated to its preservation regardless of whether or not their generation is the one to see it fire. The rites, rituals, and artifacts of this religion that act as a backup for the instructions on firing the Ultimate Weapon, as we see when Cornelius tries to explain it all to the President.

The transmission media of memes and religious fervor are not—as we see in the film—perfect. Language and culture are lossy media. But they do get the characters close enough so that they can figure out the rest on their own.

How to make sure it can be figured out?

The weapon is initialized by placing the sacred stones on the proper pedestals. But which stones go on which pedestal? Fortunately, anyone with a visual or tactile sense can match the right stone to the right pedestal by matching the pattern. Furthermore, since the stones and their fitting are almost triangular, it is easy to tell how they should be seated. See the pilot of Sci-Fi University for more about these affordances and constraints.


The main challenge within this part of the bigger challenge is the spans of time involved. Given 5,000 years between firings, entire cultures, countries, technologies, and languages come and go in that time. How many people alive now are fluent in languages from 5 millennia past? You have to use mechanisms that don’t depend on culture, technology, or language. Physical affordances and constraints are a fine tool for these reasons.

How to let users know they’re on the right track?

When a little bit of the required element is provided to the placed stones, there is immediate feedback as small rectangles open just a bit near the tops. It is this partway state that indicates to the protagonists that, even though they haven’t completely supplied enough material, they are on the right track. This clue gives them enough of a signal that they continue trying to deduce control of the interface.


What activation materials to use?

The stones require some small amount of each element to be supplied to their topmost surface to become active. For three of the four (earth, air, water), these elements are in abundance here on Earth.

To consider the fourth, fire, takes us to strategic questions about the design.

Why this design?

It’s possible that the design of the weapon is constrained by some unknown cosmogenic power source in the stones. <handwaving>It’s mystical physics that requires that there be 4 stones and 4 pillars and smooches in the center.</handwaving> But it is of course of more use to us to imagine that it wasn’t, but some deliberate design. Which leads me to ask why wasn’t it a single big button? Well, I can see five effects this particular design has.

1. It allows you to disable the weapon

A major part of the plot involves the fact that the stones—keys to operating the machine—have been removed from Earth to keep them safe. This proves to be a major complication and a minor mystery to the protagonists, but is in fact one of main features of the weapon. Much of it is architectural and would be very difficult to move. By adding activation keys, the Mondoshawans ensured that they could disable it if necessary.

2. It tests for environmental stewardship

If three of the activation elements were not available: earth, air, and water, it would raise serious issues about the human caretakers of the planet. Do they stand on a scorched earth? Is their air ruined? Have they let the water of Earth, like what happened on Mars, evaporate into space? Any of these scenarios raise serious doubts about whether life on the planet is worth saving. Or is there to save.

3. It tests for cultural stewardship

Unlike the other elements, fire isn’t as abundant. In pre-cultural Earth, it was an accident of geothermal activity and lightning. To be able to control it to a level that it can be applied to the stone speaks of a fundamental level of cultural and technological advancement. If humans have not kept stewardship of their culture well enough to be able to control fire, it again raises the question of whether they are worth saving.

The key to the weapon room similarly tests for cultural stewardship. It looks like a fragile thing, made of thin perforated metal. Having a reverant group treat it as a holy artifact ensures that it will not get crushed or rusted, and in the process lose access to the room that contains the weapon.

4. It tests for basic intelligence

The affordances and constraints that help the characters position the stones correctly require a level of basic, intelligence as individuals. Can they do pattern matching? Do they understand simple physics? This isn’t the strongest of tests, but I’m pretty had humans devolved to primates by this point or distracted by constant war, they’d have been screwed.

5. It tests for a capacity for love

The “fifth element” (ignoring wu xing and similar actual 5-element philosophies) in this case is love. In the film Korben must overcome his reticence to confess his love for Leeloo. When he does, she realizes that humanity—including its capacity for war—are worth saving, and the weapon fires. Love is a big word of course, so it’s not clear whether familial, friendly, platonic, or even purely sexual love would suffice, but perhaps it doesn’t matter. The designers wanted to make sure that humanity still has some capacity for feeling intense care toward another. If not, why bother saving them?

It’s made a bit dubious because it’s specifically for the love of an “ultimate warrior,” a “perfect being.” Leeloo looks very much like a very fit, pretty example of one of a human, who has shown very human capacities for joy, pain, fear, delight, &c. It’s not that hard of a test for Korben to love her, except, to overcome his own sense of awkwardness and humility and openness to rejection (in front of a small crowd, no less.) If she had looked like a Mangalore it would have been a more difficult—and more telling—test of the capacity for altruistic love, but perhaps that’s not the point.

These five effects seem like pretty good reasons to design the interface to this weapon in this particular way. In total, they test to make sure there’s a humanity there worth saving. And fortunately for humanity in 2263, Korben (and the culture that produced him) prove just enough of a match.


As if that wasn’t enough, bear with me for just two more bits of nerdery about the weapon. These are a bit extraneous to the interface, but derived from study of the interface, and so may be of note to readers.

1. We can’t ignore the fact that the Ultimate Evil plummets toward the Earth in a straight line. A straight line, that is, that puts it directly in the path of the ultimate weapon, which fires a perfectly straight line. And recall that the weapon is on a planet that’s orbiting around a star, and precessing its rotational axis. This is too slim a chance to be coincidence. It stands to reason that this is not, as Cornelius says, a sentient evil bent on ending “all life” (which would just veer a few degrees out of the way to safety), but part of the same system as the weapon, designed to identify and tempt the worst of people, i.e. Zorg, and try and thwart these aspects of humanity that are ultimately tested. If that’s the case, and the Mondoshawans installed the weapon, did they, by extension, install the Ultimate Evil as well? Is this some sort of “invisible fence” meant to keep humanity in check, and destroy it if it ever evolves for the worse?

2. Many of these same issues have been addressed in the real world by the designers of containers of radioactive waste (the danger of which persists between 10,000 and 1,000,000 years) and, more positively, the the Long Now Foundation working on its main project, the Millennium Clock. For those unfamiliar with this project, it is a prospective, large-scale clock that once built, will chime every thousand years. The clock mechanism and function is intended to last for 10,000 years. The Long Now foundation is faced with similar long-term design challenges and have come to some similar conclusions as the designers for the film. The clock will be made of Bronze Age materials and technology, and it will be situated in the desert. The clock will largely be self-maintaining, but the Foundation is also developing a Rosetta Wheel containing many, many examples of existing human language, useful for decoding written instructions. The idea itself has many elements that ensure its persistence as a meme, being simple, distinct, and a powerful embodiment of an important message about the value of long-term thinking. The Long Now Foundation was begun in 01996, the year prior to the release of The Fifth Element. I am a huge fan of the Foundation and its initiatives, and I encourage readers to read further to learn more.