Michael Bay's recent Transformers bears little resemblance to the original children’s cartoon series that launched itself into the popular consciousness in 1984. Like the original series, the most recent movie adaptation is based on an epic battle between good and evil alien robots—Autobots and Deceptacons, respectively—who hail from the planet Cybertron and can disguise themselves by transforming into vehicles. Though the characters and plot are borrowed from the original cartoon, the similarities end there. Bay, the director behind action flicks such as Armageddon and The Rock, molded Transformers in his testosterone-heavy style, replete with fast cars, explosions, and fearsome robots.

The science of robotics has developed at a rapid clip since the '80s, paralleling the great advancements in other technologies made over the last two decades. State-of-the-art robots from the time of the original Transformers included the Japanese Biper-4, an experimental biped walking robot developed at the University of Tokyo, which needed paddle-like feet to stay upright. Today, increasingly powerful robots are being built at universities like MIT and Carnegie-Mellon, and by private companies such as Sony, Honda Robotics, iRobot, and Boston Dynamics. It is now possible to buy a robotic dog and a robot that washes your kitchen floor; robots that can navigate complicated outdoor terrain with six legs; and robots that can exhibit convincing human emotions, among other things.

Robots that magically transform into F-16 fighter jets—as depicted in Bay's Transformers—are still the stuff of sci-fi, of course. "Humans are very good at designing special-purpose machines—things that do one thing very well," says Matt Malchano, a senior robotics engineer at Boston Dynamics. "In order for robotics to be anything like what we see in Transformers, we need to design something that does many things well."

"The idea of a robot that can transform into a car from a biped is not outside of the realm of possibility," says Hani Sallum, a mechanical robotics engineer at Draper Labs. "Take Bumblebee—a Camaro that turns into a guy that runs around. That's within the realm of reason given where we are now. I think it's doable. It's not necessarily useful, but it's doable."

Then again, there are many fantastical aspects of the movie that simply aren't feasible. "The aspect of the reconfiguration where the robots could look at something and then turn into that thing is one of the holy grails of robotics," says Sallum. "Those holy grails are swarm robotics—lots of robots working together—and biomimetic robotics, which are robots that mimic the behavior of organic things. What these robots were able to do was many steps ahead of what I think we even think is possible given our current abilities manufacturing-wise."

The size of the Transformers robots vastly exceeds that of real-life robots today. The lumbering behemoth Optimus Prime, for example, transforms into a red 18-wheeler semi-truck. Most modern-day robots in the real world still aren't nearly at that size. "There are different aspects of machines that scale differently with increasing size," explains Sallum. "If you double the height of a robot, just by scaling everything up, you end up multiplying the mass by eight. If you were to double your height, your arm would weigh eight times as much, so if the Transformer threw a punch, that's a considerable amount of mass moving at a high speed—that's a lot of power. That would be very hard to deal with in terms of the motors and the actuators. If we could make robots as tall as the robots in Transformers, they would walk a lot slower, and the way they fought would be a controls nightmare—to move that much mass around that fast, in a controllable fashion."

So are there movies involving robots that are more realistic than Transformers? Sallum points to two: ED 209 from Robocop and the four-legged AT-AT walker from The Empire Strikes Back. "ED 209 was bipedal, but it had an extremely large footprint, and an articulated foot, so balance would have been an easier problem to solve. The robot was fairly short and squat, so in terms of balancing it definitely had the look of a design that was optimized for the easiest balancing, walking algorithm possible. The AT-ATs from Empire Strikes Back always moved one foot at a time. The thing always looked like it was statically stable; it always had three feet on the ground, and it wasn't doing anything like a trot or a gallop, which is a completely different and harder problem." It is interesting to note that the more realistic robots seemed to be from older movies. With the advent of computer-generated (CG) animation, robots in movies have been able to move far beyond the constraints of engineering in the physical world—leading to ever more fanciful and futuristic creations.

CG imagery is restricted only by the bounds of imagination. (A popular recent advertisement for the French Citroen car company featured a Citroen C4 transforming into a dancing robot; the advertisement was made with the help of computer animation.) Bay's live-action version of Transformers uses CG in spades, thanks in a large part to the efforts of renowned special-effects crew Industrial Light & Magic. Jessica Laszlo, a digital artist at ILM, contributed to Transformers and many other big Hollywood movies. "Ten or fifteen years ago, movies relied more on robots—the first Jurassic Park, say, where they still used animatronics—but they've moved away from that," Laszlo says. "If you build it, it's a lot harder for them to say, 'Can you make the tail longer and thinner?' because maybe they can't."

The Empire Strikes Back, which came out in 1980, and Robocop, which came out in 1987, didn't have the luxury of using the CG imagery that Transformers relies on. ED-209 from Robocop was painstakingly constructed as a series of full-size physical models, and animated using stop-motion techniques—a far cry from where we are today in terms of robot movies.

Using CG, the most bizarre sci-fi visions can look eerily realistic. Robots that have the capability to morph at will can be effectively modeled and quickly revised on a computer screen, instead of being physically built in a slow, meticulous process. Laszlo walks us through the steps. "Let's say you have Megatron," she says. "First there's the concept. So Michael Bay works with concept artists with what he wants Megatron to look like. Then he comes to ILM, and they have to build a CG model—a computer generated model of all the pieces and how the robot moves—and the people who do that are called modelers. They set it up with all sorts of controls for how they want the robot to move, so the animators can then animate the robot. A big giant robot moves differently from a little tiny robot. They have to convey weight and volume, and how it moves. Once it's animated, then a TD, or technical director, will then light it in the environment it's going to be in. In the live action plate (footage), the TD lights the CG characters, the compositor takes the light and the CG characters and the smoke and whatever else, and integrates the final shot. On any shot, ten or fifteen people might have worked on that shot from start to finish."

Computer-generated or not, part of the allure of Transformers is that the characters are supposed to be beyond the realm of human possibility. The first Transformers movie, released in 1986 as an animated feature film, sported the tagline "Beyond Good. Beyond Evil. Beyond Your Wildest Imagination." Though our knowledge of technology and robotics has drastically increased since that time, the newest incarnation of Transformers still manages to be one step ahead of reality.