[This Debugger story explains the promise of and our progress toward effective and commonly available holograms (actually volumetric images); our colleague Frank Biocca is one of the experts quoted and the original story includes three videos and an additional image. For related news see USA Today’s story about IKIN’s new RYZ, “the first personal hologram platform”; Digital Trends’ story about Looking Glass Factory’s 3D holographic display and software that transforms any 2D image into a 3D one; and a short Bloomberg video about the Swiss company Inverse’s 3D hologram meeting technology that just won a CES 2021 Best of Innovation Award. –Matthew]
[Image: Credit: Janet Mac]
We’re ‘Maybe Five-ish’ Years Away From Princess Leia Holograms
Or to be more precise, volumetric Princess Leia images
By Angela Lashbrook
January 12, 2021
You’re sitting at your dining room table, drinking wine and chatting with your closest friends and family. Music plays gently from the stereo, and the room has a happy, congenial energy. But there’s only one actual glass of wine on the table, one small plate of charcuterie, one silverware setting.
You’re the only person physically sitting in your dining room. Everyone else gathered around it is a hologram, and though they can see you and you can see them and you can talk to each other as if you’re physically together, you’re not. You can’t touch them; if you do, their image will refract and distort. But emotionally, it feels like you’re together. It’s not as good as the real thing (no hugging) but it’s pretty close.
This is, of course, a fantasy — one that began in earnest when R2-D2 projected a hologram of Princess Leia delivering an urgent message to Obi-Wan Kenobi in 1977’s Star Wars: A New Hope (though technically, the first fictional hologram appeared in Isaac Asimov’s 1951 Foundation trilogy).
Movies are now replete with the technology; Back to the Future Part II (1989), Iron Man (2008), and Black Panther (2018) are just a few of many that feature holographic displays. Despite the decades-long prevalence of this technology in fiction, though, we still seem to be no closer to dining with our holographic family members.
A number of hurdles stand in the way of ever getting a holographic message from your friend, from the logistical (funding is always a problem) to the potential hazards involved (some early forms of holograms are potentially dangerous).
Still, researchers are hard at work creating holograms that, hopefully, will be available to consumers — some day. There’s a distinct possibility that, in our lifetimes, we will have 3D, Princess Leia-like “holograms” from which we can receive messages and even interact with in real time. Considering what an exhausting bummer Zoom calls have become, and the inability for text messages or emails to convey the full emotional depth of a conversation, a future with holographic dinner guests, conference speakers, or dates could make inclement weather or, god forbid, future pandemics more bearable. And science is well on its way to making this happen.
What is a hologram?
First, let’s get one, very important thing out of the way. What is commonly called a “hologram” — namely, a 3D depiction of an object or figure projected into the air — is not, actually, a hologram. Nor is Kanye West’s extremely expensive, arguably creepy projection of the dead Robert Kardashian that Kanye gifted to Kim this year, or even the animated Japanese pop star Hatsune Miku.
“Strictly speaking, they are very good illusions, but they are not real holograms,” says Frank Biocca, PhD, a professor of Informatics at New Jersey Institute of Technology who studies augmented and virtual reality. They’re actually modern versions of a 1862 invention known as “Pepper’s Ghost.” In Pepper’s Ghost illusions, a transparent piece of fabric or glass is hung at usually a 45-degree angle, onto which an image is projected, typically from below but sometimes from above. To the audience, it looks like a ghostly figure is moving around the stage, but get close and it becomes clear that it is anything but real.
Princess Leia, floating in midair as she pleads for help from Obi-Wan Kenobi, is not technically a hologram, either. She’s a volumetric image, as are many of the floating figures or objects that are projected into thin air that we typically think of as holograms — essentially, an image that takes up three-dimensional space, according to Erich Nygaard, who worked on volumetric display research at Brigham Young University.
Holograms are made by recording the light scattered by an object, and then presenting it on a typically two-dimensional surface in such a way that it appears 3D. As you turn your head or move around a true hologram, it will appear as if you’re looking at another angle of the object. These are actually common in day-to-day life: You see them on shiny credit cards or security stickers in your passport. It looks multidimensional, but it isn’t actually an image that’s being projected into the air; it’s limited to the two-dimensional surface.
So, real holograms are fairly common already. But volumetric displays — those 3D characters from the movies — are limited to laboratories… for now.
Volumetric displays are how the magic happens
Daniel Smalley, PhD, is an associate of electrical and computer engineering at Brigham Young University in Provo, Utah. His 2018 paper, which he calls the Princess Leia project, has created one of the most impressive examples of volumetric images — like the one of Princess Leia — in existence.
In Smalley’s project, a laser beam traps and steers a particle (in this case, of cellulose) around a small area. As the particle moves, it’s illuminated by lights in different colors, thus creating a line of light that forms into an image — a tiny butterfly in this case.
“A good way to think about it is like a firefly or a sparkler,” says Smalley. When you drag a sparkler through the air, it looks as if it creates a line of light. “The accumulated effect of all this is that you see an image floating in the air that you walk around and see from every angle.”
Right now, “we have a single particle that we scan through a complicated path in the air to make an image. But in the future, we want to have a whole bunch of particles in the air and move them in a really simple path together to make an image,” says Smalley. The more particles you use, the bigger and more complex the volumetric display image can become. Eventually, these displays could even be life-size.
Back to the future
Depending on funding and staffing logistics, says Smalley, it could be “maybe five-ish years” before a volumetric image like Princess Leia’s in Star Wars could be projected on a table in a laboratory. As for when you could have your own Princess Leia?
“Display technology is a terrible business to be in,” he says. “The history of displays is strewn with the carcasses of good technologies that just weren’t marketable for all sorts of reasons, including that existing display manufacturers routinely cannibalize and destroy their own children in order to prolong the profitability of legacy technologies.” But he’s optimistic that volumetric displays will reach consumers eventually. Imagine, he says, the disembodied, three-dimensional head of your friend being projected out of your phone or your watch. “That disembodied head of your friend could talk to you but could also turn and look at someone else in the room and talk to them,” he says. “If sense of presence is important, and experience suggests that it is, this technology might have a chance of getting outside the lab and becoming commercial.”
Still, it won’t be entirely like Princess Leia in the original Star Wars, and that’s because the way the film depicts her is — as far as anyone knows — impossible.
“The main challenge with the ‘Princess Leia’ experience is similar to the lightsaber challenge — how do you simply stop light from traveling in midair?” says Ricardo Figueroa, PhD, an associate professor of motion picture science at Rochester Institute of Technology. “The Princess Leia hologram is generated from a small lighting source in R2 and the light is directed straight into the air, and as far as we know, this is impossible to do.”
Light continues to travel through the air until it’s stopped by something. This is why Smalley uses the tiny particle of cellulose in his volumetric display — it’s something for the light to hit. Other researchers have used smoke, humidity, or crystals to create similar effects.
But we’re getting closer to creating the pure lightform Princess Leia from Star Wars. “Numerous research groups and companies are looking into using lasers to excite air molecules so that they emit light,” says Ben Cumming, PhD, a research fellow in Physics at RMIT University in Melbourne. This is very difficult, expensive, and even potentially dangerous to do, as the excited air molecules get hot and, thus, difficult to interact with or even to look at.
Biocca thinks augmented reality glasses are one of the easiest ways to produce three-dimensional, real-looking images in space. The technology is progressing further along than volumetric displays, and though there’s clearly work yet to be done — Google killed its augmented reality project, Google Glass, years ago, and HoloLens has pivoted from consumers to workplaces — if the tech gets good enough, it could reach consumers in a way that, hopefully, is fun, not creepy. According to MacRumors, Apple may be developing its own augmented reality glasses, with some experts speculating that the device could come as soon as this year, though this has yet to be confirmed.
One lesson (among many) that we can take away from covid is our need for telecommunications technology that replicates real life, or at least comes close. Zoom is exhausting, phone calls are great but obviously not perfect, and thousands of people are whiling away alone in their homes or, worse, in hospital rooms. The three-dimensional presence of a loved one could ease that pain. It could also, quite simply, make it easier to invite a friend to a dinner party when she’s traveling for work, or so that you could demonstrate for your mom the new cookie-rolling technique you figured out. The technology could also be useful for people with disabilities whose conditions make it difficult to leave their homes.
Ideally, we won’t be making any desperate pleas with Jedi masters to save the galaxy. Though at this point, would that really be such a surprising outcome?