Watch as digital artist Seb Lee-Delisle recreates the old school video game Asteroids with a laser. But why use a laser? There’s actually a good explanation for this. In the olden days of arcade video games, the screens on most games were like Pac-Man or Donkey Kong…a typical CRT refreshed the entire screen line-by-line many times a second to form a pixelized scene. But with vector games like Tempest, Star Wars, and Asteroids, the electron beam was manipulated magnetically to draw the ships and rocks and enemies directly…and you get all these cool effects like phosphor trails and brighter objects where the beam lingers. When you play Asteroids on a contemporary computer or gaming system, all those artifacts are lost. But with a laser, you can emulate the original feel of the game much more closely.
You’re not going to want to because it’s 17 minutes long, but you should watch the whole video…it’s super nerdy and the explanations of how the various technologies work is worth your while (unless you’re already a laser expert). I loved the bit near the end where they slowed down the rate of the laser so you could see it drawing the game and then slowly sped it back up again, passing through the transition from seeing the individual movements of the laser to observing an entire seamless scene that our mind has stitched together. In his recent book Wonderland, Steven Johnson talks about this remarkable trick of the mind:
On some basic level, this property of the human eye is a defect. When we watch movies, our eyes are empirically failing to give an accurate report of what is happening in front of them. They are seeing something that isn’t there. Many technological innovations exploit the strengths that evolution has granted us: tools and utensils harness our manual dexterity and opposable thumbs; graphic interfaces draw on our powerful visual memory to navigate information space. But moving pictures take the opposite approach: they succeed precisely because our eyes fail.
This flaw was not inevitable. Human eyesight might have just as easily evolved to perceive a succession of still images as exactly that: the world’s fastest slide show. Or the eye might have just perceived them as a confusing blur. There is no evolutionary reason why the eye should create the illusion of movement at twelve frames per second; the ancestral environment where our visual systems evolved had no film projectors or LCD screens or thaumatropes. Persistence of vision is what Stephen Jay Gould famously called a spandrel — an accidental property that emerged as a consequence of other more direct adaptations. It is interesting to contemplate how the past two centuries would have played out had the human eye not possessed this strange defect. We might be living in a world with jet airplanes, atomic bombs, radio, satellites, and cell phones — but without television and movies. (Computers and computer networks would likely exist, but without some of the animated subtleties of modern graphical interfaces.) Imagine the twentieth century without propaganda films, Hollywood, sitcoms, the televised Nixon-Kennedy debate, the footage of civil rights protesters being fire-hosed, Citizen Kane, the Macintosh, James Dean, Happy Days, and The Sopranos. All those defining experiences exist, in part, because natural selection didn’t find it necessary to perceive still images accurately at rates above twelve frames a second — and because hundreds of inventors, tinkering with the prototypes of cinema over the centuries, were smart enough to take that imperfection and turn it into art.