Hello science fiction fans! Welcome to another Science Fiction Problems! This week we’ll be discussing another big thing
in sci-fi books and movies (especially movies), holograms! As one of the more widely used fictional technologies, most people are familiar with holograms. The Holodeck on Star Trek is a more familiar example, where the characters enter a room and the computer (usually at their command) builds the rooms and people around them, creating a visibly real environment. Today I’ll be taking a look at some of the problems we currently have with the technology, and how it might be reasonably done both in real life and in your story.
Hologram, My Foot! That’s “Hard Light”!
I know I’ve picked on Star Trek a lot through these posts, but in reality, a lot of the technological ideas in the show, good and bad, gain public popularity and shape the impressions many people have about what is mechanically possible. This happens with other sources, of course, but Star Trek’s a heavy-hitter in this area. One of the things from the show I always really (really) wanted to see in real life was the holodeck- being able to go into a room and do whatever you wanted, limited only by your imagination and the computer’s ability to replicate sounded pretty cool to me. Unfortunately, as I discovered on further examination, the technology is far more fantasy than science.
You may recall from the show that characters can interact with objects and characters within the holodeck as if they were solid, real-world objects. This actually means that the holodeck is not a hologram at all, but something called “Hard Light”, a concept more at home in comic books than science fiction. A hologram is a 3-dimensional projection of an image into space, usually meant as an illusion or simulation of a real world object. It is, however, by definition not solid. So, the
holodeck’s holograms aren’t really holograms at all, they’re “hard light constructs”, that is, projections of objects that are somehow made solid.
The distinction is important because holograms are technically possible, whereas hard light is not. Right now, projecting into thin air is impossible, but we only have to figure out how to project onto empty space (or what looks like it), and we’ll have our holograms. However, nothing can make those holograms solid, making hard light possible. Obviously, we can’t just make light ‘hard’, as the name suggests, so in order to get the effect or something like it, we need to figure out how to make holograms feel real.
Haptic Interfaces: Making the Unreal Feel Real
So, you can project a 3D image, but you can’t make it solid- so what’s the next best thing? Making it feel like it is, of course! Haptic technology is the application of forces such as vibration or pressure to the human body in order to simulate touch sensation. You may have a cell phone with a touch screen which features haptics- the simplest being a small vibration created to simulate button presses. The problem with this method is that it is difficult to make the vibrations specific enough so that they are associated with the button, and it’s impossible to simulate textures. This technology is quickly being replaced, however, as electro-vibration has come on the scene.
Finally, a Use for the Obligatory Jumpsuit
While using a surface for haptic feedback would defeat the purpose of holograms, it would be possible to create a glove or even a full-body suit that would accomplish the same task on a larger scale. Using a similar electrical method (further developed along those lines), the technology could even incorporate electrical shocks to simulate wounds, as this company has done for knife cuts and bullets. By synchronizing such a suit to the computer projecting the holograms, the system could give the illusion of texture to their shapes. They would still not be solid, but it’s the next best thing, and it’s far more reasonable than ignoring the problem entirely and settling for “hard light”.
Well, that’s all for this week. Next week, I’ll be talking covering a new topic, so stay tuned! Until then, how would you make the holograms solid, to create the ‘hard light’ effect? How have you seen this handled in your science fiction? Let me know in the comments below!