Ever since I saw a 1-foot-high holographic Carrie Fisher plead, "Help me, Obi-Wan Kenobi," I've been waiting for a 3-D video player to call my own. I'm not talking about fake, View-Master-style 3-D that lets you look at an image from only one angle—you can already get that on a $3,000 laptop. That "360-degree hologram phone" you read about last week? It's not even a real hologram, just a stereoscope that's 3-D from left to right, not up and down. Impressive? Sure. A video hologram that lets you check out your subject from front to back and top to bottom? Not even close. And why would anyone want to call me on my hologram phone if they can't stand on their tiptoes and check out my bald spot?
Sci-fi movies and TV shows do a great job of visualizing our holographic future because holograms are way easier to fake than to make. Step one: Hire an actor to play the hologram. Step two: Make him look kind of blurry. Along with Princess Leia, some pioneering examples of the actor-as-hologram technique are Rimmer from the 1980s BBC space comedy Red Dwarf, Orlando Jones' holographic librarian from 2002's The Time Machine, and Star Trek's recreational holodeck.
Real-life holographic gadgets are always getting our hopes up—and then letting us down—for a good reason. Unlike the teleporter and the faster-than-light spaceship, hologram technology is grounded in real science—it's just taking longer to bloom than anyone expected. Holographic photography was invented in 1947. Stephen Benton, one of the format's pioneers, started working on a holographic television for Polaroid in the 1960s. But it wasn't until MasterCard started putting holograms on credit cards in 1983—to deter counterfeiters and because they looked really cool—that the rainbow-tinged pictures crossed over from scientific marvel to cheesy pop-culture fad. Remember the special hologram covers on National Geographic and Sports Illustrated? What about that store in the mall that sold pricey holographic photos of animal heads and jutting faucets?
At the height of the craze, hologram-starved consumers were willing to overlook the fact that the format was only good at showing, as Benton said, "three-dimensional images of small dead things." (They were also willing to overlook that Sega's Hologram Time Traveler arcade game wasn't a hologram at all, just a trick done with mirrors.) When jutting faucets stopped being cool, the next logical step was to create holographic video. The logical step was a lot easier to take than the huge technological leaps required.
Taking even the simplest holographic photo requires conditions closer to a clean room than a movie set. To create a hologram, you have to bounce a laser beam off an object, then cross the path of that first laser with another laser. (Click here for a full technical explanation.) The big limitations here are that there can't be any other light in the room and you have to hold the object you're shooting completely still. That's why the Sports Illustrated cover of a holographic Michael Jordan shows His Airness sitting still rather than soaring for a thunderous slam dunk.
Wannabe home holographers can get a taste of the technology's maddening limitations by purchasing the do-it-yourself, $99 Litiholo kit. Make your own holograms! Just be sure that the object is smaller than the kit's 2-by-3-inch holofilm and can be held perfectly still in the dark for five to eight minutes. ("Vibrations are the enemy of holograms," warns the manual.) Put that Princess Leia costume in the closet—you're going to be hologramming your action figure collection.
Shooting holovideo isn't technically impossible, but it's likely decades away. The world's most advanced video camera probably belongs to NASA's space-flight holography program, SHIVA. While the camera can capture a laser-lit vial of liquid at 30 frames per second, the actual filmed area is only a centimeter wide, and the resulting video has maybe 1 percent of the granular detail we're used to. Maybe that's a huge breakthrough for zero-G lab tests, but filming actors will require millions of times more bandwidth and processing power.
One way to get around the problems with holovideo is to forget about shooting on film and instead create computer-animated holograms with the same sort of software that was used to render The Polar Express. But how would you display it? The trick to a hologram photo is that, instead of colored inks, its surface contains tiny ripples that scatter light waves in the original 3-D pattern captured in the photo shoot. That pattern can be printed without special chemicals on almost any hard surface—there's even a company that laser-etches holograms onto lollipops, sushi, and other edibles. But to display holographic video, you'd need to morph each tiny ripple 30 times per second—that's pretty much impossible to do on any solid medium. You also can't show a hologram on standard TV and computer screens, which project all of their light in only one direction: forward. To create a hologram on-screen, you'd need to aim each pixel in a different direction.
Stephen Benton's successors at the MIT Media Lab have prototyped a solution—a video monitor that has a tiny, computer-controlled moving mirror behind each pixel. The mirrors, powered by three off-the-shelf PCs with NVIDIA graphics chips, aim the light from each pixel in such a way that a 3-D image appears in front of anyone facing the screen. For now, these computer-generated holovideos are only 6 inches high, only 3-D from left to right, and update only twice per second.
The MIT researchers hope they'll be able to do full video in three or four years, but they won't be making Madden NFL 2008. The best we can hope for is HoloPong—instead of moving back and forth across the screen, the ball will come flying straight at your head. It's inevitable that as microprocessors and graphics chips keep getting more powerful, the MIT system—or somebody else's system—will evolve into an off-the-shelf, high-resolution, 3-D video console. You'll just have to hold your breath for another 20 or 30 years.