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.


Perhaps the most unusual interface in the film is a game seen when Theo visits his cousin Nigel for a meal and to ask for a favor. Nigel’’s son Alex sits at the table silent and distant, his attention on a strange game that it’s designer, Mark Coleran, tells me is called “Kubris,” a 3D hybrid of Tetris and Rubik’s Cube.


Alex operates the game by twitching and sliding his fingers in the air. With each twitch a small twang is heard. He suspends his hand a bit above the table to have room. His finger movements are tracked by thin black wires that extend from small plastic discs at his fingertips back to a device worn on his wrist. This device looks like a streamlined digital watch, but where the face of a clock would be are a set of multicolored LEDs arranged in rows.  These LEDs flicker on and off in inscrutable patterns, but clearly showing some state of the game. There is an inset LED block that also displays an increasing score. Continue reading

Gestural Spheres

While working on some other material this weekend, I just noticed two unusual, but similar gestures from different movies in 2015, which are gestures on the outside of spheres.

First, the Something control sphere from Tomorrowland.


And, the core memories in Inside Out.


The gestures are subtly different (Tomorrowland is full palm, Inside Out is two fingers) and their meanings are different (Tomorrowland is to shift direction of travel of the time camera, Inside Out is to scrub the time itself) but they are a nice gestural rhyme of each other.

The Inside Out image reminds me that I really, really need to do a full retrospective of interfaces in Pixar movies, because they are quite extraordinary in the aggregate.


Hover technology is a thing in 2015(1985) and it appears many places.



When Marty has troubles with Griff Tannan he borrows a young girl’’s hover scooter and breaks off its handlebar. He’s able to put his skateboarding skills to use on the resulting hover board.

Griff and his gang chases Marty on their own hover boards. Griff’s has a top of the line hover board labeled a “Pit Bull.” Though Marty clearly has to manually supply forward momentum to his, Griff’s has miniature swivel-mount jet engines that (seem to) respond to the way he shifts his weight on the board.



George requires traction for a back problem, but this doesn’’t ground him. A hover device clamps his ankles in place and responds to foot motions to move him around.

Hover tech is ideal for leaning control, like what controls a Segway. That’s just what seems to be working in the hoverboard and hovertraction devices. Lean in the direction you wish to travel, just like walking. No modality, just new skills to learn.

Carrier Control

The second instantiation of videochat with the World Security Council that we see is  when Fury receives their order to bomb the site of the Chitauri portal. (Here’s the first.) He takes this call on the bridge, and rather than a custom hardware setup, this is a series of windows that overlay an ominous-red map of the world in an app called CARRIER CONTROL. These windows represent a built-in chat feature for discussing this very topic. There is some fuigetry on the periphery, but our focus is on these windows and the conversation happening through them.


In this version of the chat, we are assured that it is a SECURE TRANSMISSION by a legend across the top of each, but there is not the same level of assurance as in the videoconference room. If it’s still HOTP, Fury isn’t notified of it. There’s a tiny 01_AZ in the upper right of every screen, but it never changes and is the same for each participant. (An homage to Arizona? Lighter Andrew Zink? Cameraman Arthur Zajac?) Though this is a more desperate situation, you imagine that the need for security is no less dire. Having that same cypher key would be comforting if it is in fact a policy.

Different sizes of windows in the app seem to indicate a hierarchy, since the largest window is the fellow who does most of the talking in both conferences, and it does not change as others speak. Such an automated layout would spare Fury the hassle of having to manage multiple windows, though visually these look more like individual objects he’s meant to manipulate. Poor affordances.


The only control we see is when Fury dismisses them, and to do this he just taps at the middle of the screen. The teleconference window is “push wiped” by a satellite view of New York City. Fine, he feels like punching them. But…

a) How does he actually select something in that interface without a tap?

b) A swipe would have been more meaningful, and in line with the gestural pidgin I identified in the gestural chapter of the book.

And of course, if this was the real world, you’d hope for better affordances for what can be done on this window across the board.

So though mostly effective, narratively, could use some polish.

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