Today I want to talk about something a little different: how we use language to describe the world, the incremental march of technology, immutable physical laws, accuracy in marketing, and how these converge in the case of a prototype product. This will probably wax a bit philosophical, so if that’s your jam, read on.
Technology moves incrementally, and batteries are a perfect example. How many times have you seen a Popular Science or Mechanics, or any of the hundred similar magazines on the newsstand, and seen eyeball-grabbing headlines sizzling like so much bacon across the front covers? Promises of new nanotechnology-enabled tech making batteries that last ten times as long and that can charge within seconds. (See here, here, here.) These advancements, however, never seem to make it into the consumer sphere. They either rely on effects that do not scale up to become macroscopic batteries that have enough power to be practical, or they cost orders of magnitude too much to make, or they require very fiddly lab conditions that are difficult and costly to build for mass production, or dozens of other issues. The next generation of batteries is, according to the press releases, always five to ten years away, and the scientists are always desperately in need of the funds to make this happen. Fair enough. But the last really big advance in consumer battery technology was the switch to primary lithium batteries (lithium iron disulfide) which first came to market in AA form in…wait for it…1989. AAAs using lithium were available in 2004. Of course, lithium ion batteries also came to market around this time, in the 1990s, which was a huge jump for consumer electronics, especially things like laptops.
My point is that these advances built on what came before them, and they weren’t a sea change. They used established technologies and emerging chemistry in new and novel ways, and battery life did increase. They came with their own downsides – who remembers early iPhone batteries expanding and destroying the phones, or people’s pants catching on fire? But they were a genuine advancement, and they’ve stuck around.
Why am I talking about this?
My point here is that truly revolutionary advancements are extremely rare. We’ve discovered (probably) most of the really obvious effects in nature, the low-hanging fruit if you will – and so we’re onto increasingly more subtle and nuanced effects. It’s unlikely that tomorrow some established scientist will discover, say, the physics that would make Star Trek-like force fields possible and practical. This is not to say that it’s not possible, just that it’s very unlikely. Those of you who listen to The Lighting Nerds know that I’m a pretty big Star Trek nerd, and there’s actually another technology that crops up in that show that I’d like to discuss: the holodeck.
For those playing the home game, the holodeck in Star Trek is a pretty magical place. It’s a giant room, essentially, with fictional (so far) display devices called holoemitters. In the physics of the show, holoemitters project a solid field -a forcefield – in an arbitrary shape – say, a plant – and then project images onto these normally-invisible shapes. (The nuts and bolts of how, exactly, this is accomplished is described variously throughout the show, but no need to get into that here.) Voila, a volumetric display space. (As distinct from a volumetric display.) Since the forcefields are little more than solid projections in the air, they can easily mimic plants, mundane household objects, an entire room, or even people, and the forcefields can move. Through complex algorithms that track the living participants in the holodeck program, the computer can modulate a forcefield to seem like water, create an obstacle course with simulated enemies for tactical scenarios, even project fully-immersive novels. (This is actually where I find little nerd heart annoyed when rooms with 360º projectors get referred to as “holodecks”, but I digress.) The point is that they’re a fully-immersive interactive environment that is (generally) indistinguishable from the real thing. Marvel fans might recognize a version of what I’m talking about as the X-Men’s “danger room”.
Marketers love terminology from science fiction. It’s easy to see why; vernacular like this acts as a terminology shorthand for a vast swath of audience who will simply understand what you’re talking about. It’s much easier to say “hologram” than to explain what is meant by “volumetric display”. But the problem with this sort of shorthand is that it’s inaccurate, and perhaps misleading.
If you follow, as I do, some of the internet’s many physics blogs, you’ll undoubtedly be aware of this tendency with another term from fiction: the “invisibility cloak” from Harry Potter. This bloody phrase gets thrown around any time a physicist manages to hide an atom behind another atom. Seriously, do a search for “invisibility cloak” on your search engine of choice, and click a few links. With ONE notable exception involving a retroreflector blanket, a projector, and a camera, these stories all involve microscopic or quantum effects. The term has become meaningless from overworked PhD candidates torturing the technological terminology to compete for those sweet sweet project funding grants*.
This is what has happened with the word “hologram”. Non-industry people now use the term to cover a huge range of completely separate effects: Pepper’s Ghost illusions, scrim projections, very high-resolution video panels hidden with clever lighting. So when a company like Light Field Lab comes around and starts dropping the term “hologram” as though it has any meaning, my eyebrows start knitting.
I would argue that it has a scientific meaning, and a sort of squishy “consumer” meaning. The dictionary definition doesn’t get us very far, as the long-accepted definition of “hologram” or “holograph” involves specialized interferometric effects using lasers. Fine, language lives, it moves, dictionary definitions are useful only as a starting place. Clearly, Light Field Lab’s technology is far, far more advanced. The other, more “consumer” meaning refers to all those things we discussed before: volumetric displays, Pepper’s Ghost effects, etched-lens displays and even VR headsets. The assertion that what Light Field Lab has created are “real holograms”, though, suggests to me something far more Star-Trekian. Light Field Lab has a demonstration video showing how close their tech gets to something like that. However, a few things in the demonstration video on their website (which was replicated for a reporter for CNET) stand out to me. There’s actually another video of their CEO talking about their technology – a talk that he gives to SMPTE, which I’ll talk about below.
In their demonstration, the angles are extremely controlled. The reporter is allowed – through some very clever window-dressing – to only see the effect from the angle that works. Secondly, the object has no real depth: what I mean by this is that the reporter puts out her hand to where she thinks the chameleon is, only to realize that this isn’t actually possible. The image necessarily comes from the display; you can’t put your hand behind the image, because there is no behind. Think trying to grab the floating 3D shapes in a Magic Eye book. It’s an (excellent) illusion. This makes interacting physically with the object impossible, as well (of course) as the fact that light has negligible mass…for us macroscopic humans, anyway.
Please don’t hear me bashing on Light Field Lab here. It’s clear that they’ve created a very cool display that’s capable, through some Clarke’s Third Law wizardry, of projecting the illusion of volumetric objects at some arbitrary distance from the screen. However, what I think they’ve created is a very advanced volumetric display, not a hologram. This is actually something that Jon Karafin addresses in the other video (The SMPTE talk) I found on YouTube. He spends a lot of time talking about what is not a hologram, and that’s something that I appreciate. He correctly points out that the various technologies that exist for creating 3D objects in mid-air all have major downsides, like – for instance – the laser-based system that creates tiny bursts of plasma in the air**, or using tiny Styrofoam beads as a sort of single “pixel” that gets whipped through the air faster than persistence of vision to “draw” shapes. These, he asserts, are not holograms, and I have to agree.
But, I assert right back, what Light Field Lab has created is not a hologram, either. Not in the sense that I think most people want to understand the term, or in the sense that most of us really want. What we want – fully view-independent, walk-around-able, opaque and animatable 3D objects that have real depth in 3D space – is not possible with current technology. It’s just not. Mr. Karafin, again to his credit, addresses this in his SMPTE talk, though he uses the example of R2-D2 projecting Leia onto the floor of Luke’s garage. And this is where I take issue with his use of the term “hologram”. It’s not the holograms promised by science fiction. It’s very cool, but it’s not that. I can understand and appreciate his reasons for calling them that: he’s making a technical point as well as a marketing one, in that he claims that his tech, in controlling the convergence of light, should be indistinguishable from a real object from the standpoint of the light itself. That may be true, and may qualify it, in a bare technical sense, for the moniker. But of course, as with laser interferometry effect holograms, it is distinguishable from a real object for a variety of other reasons.
What strikes me as strange is that this (more informative) SMPTE talk is nowhere to be found on their webpage. Neither is the CNET video, which I find inexplicable. And, it must be said, neither is any mention of the big “gotcha” with their tech, which is that it requires line-of-sight to the display. Again, this isn’t to bash their tech: from what I’ve seen, it’s very cool, and I wish I could spend some time in a room with one of these displays to see exactly what they’ve created. If there’s a crux to this long-winded and slightly meandering post, it’s this: technology moves incrementally, and while this tech is cool and represents a real advance in optical science and display technology, it’s not yet a Star-Trek-like hologram, nor should we expect it to be. What I wish is that Light Field Labs were a little clearer about this on their website, and a little more forthcoming with how exactly the technology accomplishes its effect, without giving away any of their trade secrets or proprietary information. I want them to be forthcoming because this is genuinely cool technology: it will undoubtedly (if the price and a hundred other factors are right) have vast applications in the corporate, entertainment, music, events, and communications industries, and many that I can’t even dream of right now.
Ultimately, what I think I’m arguing for here is for a bit of clear-eyed skepticism when it comes to marketing claims like “real holograms”. I’m arguing for companies that create cool display tech like this to be a little more clear about what their technology is and isn’t, because the Light Field Labs’ website is extremely – shall we say – sparing with the details. And I’m arguing for a general principle of understanding that, for the most part, technology doesn’t wake up one morning and give us terrifying alien-abduction tables because you asked for a “metal table“. It moves in fits and starts, and until we arrive at an understanding of optical physics, light, and the precise control of both that goes well beyond our current capabilities, the Star Trek-like holodeck will remain the dream of Mr. Roddenberry.
Live long, and prosper.
*University projects should be funded, don’t get me wrong.
** He also states, probably incorrectly, that contact with the plasma would kill you outright. I doubt that, but at many thousands of Kelvins, the plasma would probably mess up your skin a bit. You wouldn’t want to touch it.