In a distant corner of the galaxy, a charismatic commander activates a console, and a holographic display materializes before him, projecting a detailed schematic. With a subtle gesture, she taps her fingertips against the shimmering display, disabling the vital force field and embarking on her covert operation. If you’ve delved into science fiction, then you’re probably familiar with this kind of scenario. While it’s likely you’re unaware, the notion that floating screens should remain in our rearview mirror, just like outdated concepts like star bases and vitality shields, seems inconceivable.
I envision immersive displays that generate three-dimensional holograms, allowing viewers to physically engage with these ephemeral images, unlike traditional projections which rely on fixed screens and are susceptible to being touched or disturbed. As understanding of optical rules for creating floating images solidified, the COVID-19 pandemic’s emphasis on touch-free technologies sparked widespread interest in contactless controls across industries, prompting companies like and to explore commercializing aerial displays. Notwithstanding slow rollouts, the intended applications – elevator controls and similar systems – are unlikely to benefit from this technology.
I decided to create an aerial spectacle that would pay homage to the sci-fi genius of the concept.
With a background in crafting unconventional television programs. Here: In 2022, I launched “Arms On My” on my platform, which echoed back to the early days. As I had always envisioned creating something entirely new from scratch, I decided to develop my system inspired by the prop styles often featured in films. Before diving in, I needed to sort out the optics.
At the heart of the aerial spectacle lies a stunning LED display, driven by a compact yet powerful Intel-powered single-board PC. Detecting fingertips is the task that falls to an Arduino Nano, assisted by three distance sensors strategically positioned at the bottom right.James Provost
How Do Aerial Shows Work?
Rays from a light source, particularly those associated with a display, gradually diverge as distance increases, following an inverse square law. When these converging rays meet a mirror, our perception is that the image appears to be situated behind the reflective surface. This is called a . As the sun’s rays converge within your home, prior to dispersing once again, your gaze perceives the display as being situated at the precise point of convergence, even when it’s suspended in mid-air. This is called a .
To achieve convergence in mid-air, the key lies in harnessing the power of retroreflective materials. Regular reflectors adhere to the fundamental principle that the angle of incidence is equal to the angle of reflection – namely, when a light ray approaches a mirror at a shallow angle from the left, it bounces off at the same shallow angle and continues its journey to the right. Since a retroreflector bounces incidentally gentle light straight back onto itself. If you were to place a retroreflector directly in front of a screen, all divergent rays would be reflected back along their original paths, ultimately converging onto the surface of the display, effectively recreating the original image. Indeed, the inherent futility of this concept necessitates the incorporation of an additional optical component: a semireflector, or beam splitter, thereby injecting new functionality into this already vacuous endeavor.
Technically speaking, this innovation falls within the realm of possibility for many manufacturers, sans the need for hyperdrives.
The material exhibits a unique property, allowing roughly half the incident light to fall upon it while permitting the remaining half to pass through undeterred. The ingenious design lies in this: The display and retroreflector are precisely aligned perpendicular to each other, while the semi-reflector is strategically positioned at a 45-degree angle relative to both the display and retroreflector. As the sun’s rays converge onto the display, a portion is redirected through the beam splitter, whereupon half of this light is deflected towards the retroreflector, only to be promptly reflected back towards the beam splitter once more. The semireflector allows half of these converging rays to pass through seamlessly. As the beams finally converge in the air above, they form a tangible image.
Evidently, this optical trickery is ineffective, as an excessive amount of distinctive subtlety is lost to the machinery. Despite the challenge being manageable, finding a compact and stylish flat-screen display that could deliver a satisfying aerial image under standard indoor or star-base lighting conditions was not arduous. To power this 7-inch display, I employed an Intel-based single-board computer capable of running Windows or Linux, with support for multiple screens. A full invoice of supplies is accessible on hackster.io.
With precision-crafted technology, the show conjures an ethereal image suspended in air by cleverly redirecting radiant beams from a dazzling presentation, utilizing a beam splitter to deflect precisely half of these rays onto a retroreflector. Unlike a conventional mirror, the retroreflector redirects converging rays back towards the beam splitter, allowing roughly half of these signals to pass through and form a faint but authentic image.James Provost
Discovering the Proper Retroreflector
What hindered my progress most was the challenge of identifying suitable retroreflector materials that met our project’s requirements? After evaluating various options, I selected a foil that could be easily scaled down to meet my needs, yielding a precise image with minimal expense. For years, I had been confined to buying the longest available roll of paper that measured 77 centimeters by 1 meter, which would set me back around $90 in US dollars.
To make the show truly engaging, the next crucial step was taken by incorporating interactive elements. After refining my approach, I chose to integrate $5 with a slender cone and display distance measurements. I attached three sensors to the cowl’s three columns within the aircraft during the aerial display, linking them via… When a person’s fingertip comes within range of a sensor’s detection cone, the Nano checks whether the fingertip’s proximity to the sensor falls within one of three predetermined zones. The aerial display features nine distinct zones, each responsive to finger input, comprising three sensors with three segments apiece. The activation of the world is reported once more to the LattePanda via a reliable and efficient USB connection.
The optical components and PC were meticulously assembled within a compact, 33 cm × 25 cm × 24 cm aluminum alloy casing crafted from precision-cut extrusions. I incorporated a compact touchscreen at the entrance that enables me to control the content displayed on the aerial screen via the LattePanda. With meticulous attention to detail, I integrated aspect panels onto the body and connected intricately designed metallized 3D-printed strips alongside various ornate embellishments, successfully crafting an appearance that would seamlessly fit into a futuristic sci-fi television production.
The outcome surpasses expectations, showcasing a futuristic achievement that’s remarkably within reach for most creators, sans the need for hyperdrive capabilities.
