Gravity controls


In what may be the only mid-title interface use seen in sci-fi to date, after Barbarella completely strip-teases her space suit off, she restores artificial gravity to her space rocket. To do this, she floats to a panel and depresses one of a set of four transparent, underlit buttons. The row of buttons dim as she depresses one of them, and she drops to the fur-lined floor.

This moment quickly sets the tone for the design of the film, which is more whimsy than utility.

Wouldn’t push buttons be easy to accidentally bump while floating around in zero-g?

Why are they a hard material shaped kind of like bullets? Wouldn’t a softer material and gentler shape reduce the risk of injury?

Why are there four buttons? Are there four levels of artificial gravity that she can induce? Wouldn’t that work better as a dial? Or four different speeds of transitioning gravity? Shouldn’t the controls look a bit different to indicate their different functions?

Why does the gravity shift so suddenly? That could prove dangerous if she was precariously positioned in the air, especially with the bullet shapes protruding from the floor. Best would be a more gradual transition from zero- to one-g.

In zero-g, pushing the button would simultaneously push her away from the wall, increasing the height of her fall. Shouldn’t she have a handle to grip and keep herself anchored?

Then again, why does she need a physical control at all? Once she has her helmet off, why not just speak to Alphy (the conversational computer that we’ll meet in a later post) and have him turn it on slowly?


Despite these questions, there are three things I really like about the design of this control.

  1. The floor is covered in fake fur, which cushions her fall a bit. Hopefully there is padding beneath the fur lining as well, though this is less necessary if the transition is made more gradual.
  2. The control is placed on the floor, which means—since she has to be near it to activate it—her fall is minimized. Of course this raises questions about accidental deactivation later by a foot or a sexy space pillow fight, but let’s presume that’s a different control entirely for safety reasons. Then a design improvement might be to have the buttons recess into the floor after activation.
  3. The buttons are dim when the gravity is turned on. Ordinarily buttons should be illuminated when a system is on, but humans are best adapted to working with gravity, so the on switch should draw attention.

Destination threshold

As David is walking through a ship’s hallway, a great clanging sounds from deep in the ship, as the colored lights high in the walls change suddenly from a purple to a flashing red, and a slight but urgent beeping begins. He glances at a billiards table in an adjacent room, sees the balls and cue sliding, and understands that it wasn’t just him: gravity has definitely changed.


There are questions about what’s going on with the ship that the gravity changed so fast, but our interest must be in the interfaces.

Why did David not expect this? If they’re heading to a planet and the route is known, David should know well in advance. The ship should have told him, especially if the event is going to be one that could potentially topple him. Presuming the ship has sensors to monitor all of this, it should not have come as a surprise.

The warning itself seems mostly well designed, using multiple modes of signal and clear warning signs:

  • Change in color from a soft to intense color (They even look like eyes squinting and concentrating in the thumbnails.)
  • A shift to red, commonly used for warning or crisis
  • Blinking red is a hugely attention-getting visual signal
  • Beeping is a auditory signal that is also a common warning signal, and hard to ignore

After David sees these signals, he walks to wall panel and presses a few offscreen buttons which beep back at him and silence the beeping, replacing it with overhead pulses of light that race up and down the hallway. Over the sound system a male voice announces “Attention. Destination threshold.”


Why should David have to go find out what the crisis is at the wall interface? If he had been unable to get to the wall interface, how would he know what happened? Or if it required split-second action, why require of him to waste his time getting there and pressing buttons? In a crisis, the system should let you know what the crisis is quickly and intrusively if it’s a dire crisis in need of remedy. The audio announcement should have happened automatically.


The overhead lights are almost a nice replacement for beeping. It still says, “alert” without the grating annoyance that audio can sometimes be. (There’s still a soft “click” with each shifting light, just not as bad.) But if he’s able to silence the audio at this wall panel, why wasn’t he able to silence the race lights as well? And why do they “race” up and down the hallway rather than just blink? The racing provides an inappropriate sense of motion. Given that this signal is for when the crew is in an unusual and potentially dangerous situation, it would be better to avoid the unhelpful motion cue by simply blinking, or to use the sense of direction they provide to signal to David where he ought to be. A simple option would be to have the hallway lights race continuously in the direction of the bridge, leading the crew to where they would be most effective. Even better is if the ship has locational awareness of individual crew members, then you can cut all overhead illumination by 20% and pulse a light a few feet away in the desired direction between 80 and 100 percent, while darkening the hallway in the opposite direction. Then, as David walks towards the blinking light, the ship can lead him, even around corners, to get him where he needs to be. In a real crisis, this would be an easy and intuitive way to lead people where they’re need to be. It would of course need simple overrides in case the crew knew something about the situation that the ship did not.

After walking through the racing-light hallways, he turns just past the door and into the bridge, where we can see the legend “DESTINATION THRESHOLD” across the pilots HUD. He turns on a light, licks a finger, and presses another button to activate all of the interfaces on the bridge. He walks to the pilot’s panel, presses a button to open the forward viewscreen, observing LV223 with wide-eyed wonder.

This entire sequence seems strange from an interface perspective. We’re going to presume that licking his fingers was just a character tic and not required by the system. But in addition to the fact, raised above, that David seems somewhat surprised by it all, that he should have to open doors and manually turn on lights and interfaces during a crisis seems pointless. It’s either not a crisis and these signals should diminish, or it is a crisis and more of this technology should be automated.