Wednesday, May 27

Screening Science: “Pacific Rim Uprising” robots make for good action, but defy physics

Science is everywhere, especially in movies and TV shows, ranging from the chemistry in “Breaking Bad” to the physics in “Gravity.” But not all of the “science” is actually science. Each week, columnist Ethan Pak will explore scientific concepts in upcoming movies or shows and see how well they align with current academia and research.

“Pacific Rim Uprising” met my expectations only at the very end when I saw the iconic robot “Jaegers” fight off gargantuan alien-monsters, “Kaijus.”

Despite its poorly constructed plot, the film satisfied with an epic battle in the last several minutes – an assortment of skyscraper-sized robots fight alien monsters that eventually fused into a Godzilla-like creature. One by one, the robots were obliterated until Gipsy Avenger, the last Jaeger standing, dove down from the atmosphere, smashing the Kaiju in half.

As a total geek, I’m really drawn to rambunctious robots and maleficent monsters dominating the big screen. But the scientist in me can’t help but wonder how any of it works: What kind of materials and energy sources does an engineer need to construct a robot taller than skyscrapers? Do we have robots that can function like a Jaeger? Will the feat ever be humanly possible?

Out of curiosity, I decided to do some more research on what robotic technologies the world currently has and what available resources might help in constructing something Jaeger-like. Sadly, I concluded that such robots are improbable, though today’s technologies might allow for some variation on the giant robot designs.

When constructing a large robot, size is a fundamental concern. The square-cube law, first identified by Galileo, stipulates that when an object increases by a certain factor, the area of that object increases by a square of that factor and its volume increases by a cube of that factor. Here’s an example to break it down: According to the law, the 270-foot tall Gipsy Avenger would have a 2,025 times larger surface area and a 91,125 times larger volume when compared to, say, a 6-foot robot with the same proportions.

With incredible increases in dimensions come drastic changes in technical aspects. Weight is related to size the same way volume is, so if a 6-foot robot weighs 160 pounds, a 270-foot robot would weigh 14.58 million pounds. Gipsy Avenger, however, is listed as only weighing 4 million pounds – an impossible statistic, at least when taking into account Galileo’s findings.

Other technical requirements include energy demands and materials to support the robot. Increases in size and energy costs are related by a power of four, meaning a doubling in size corresponds to 16-fold increase in energy costs to move the machine. An entire nuclear reactor would be needed just to power a Jaeger. I’ll admit: The film does a good job of depicting the Jaegers’ portable nuclear reactors in their chests, so they’d technically have enough energy to power their destructive actions.

Given our current advancements in technology and the high risk associated with reactors compared to other energy forms, a portable reactor is not only impossible but also extremely dangerous. A nuclear meltdown on the top of a skyscraper weighing millions of pounds might be riveting on screen, but it’s certainly not something we’d ever like to see in real life.

As for materials, beryllium is an ideal option because it is both strong and light; it is currently used in small quantities to construct aircraft and missiles. But due to beryllium’s toxicity to humans, titanium or carbon-reinforced plastic are more likely alternatives. Both are strong materials that could hypothetically allow a Jaeger to support itself. However, the cost of durability is flexibility. A Jaeger running around with fiery blades looks amazing in a movie, but it doesn’t make much practical sense. Realistically, an actual Jaeger would stand still, cautiously taking a step or two if needed.

Flexibility also encapsulates stationary movements by the robot, such as raising an arm or leg. Given some assumptions on the weight and length of Gipsy Avenger’s arms, about 79 million pound-force-feet of torque would be needed to simply raise its arm to shoulder height.

In the film, Gipsy Avenger uses its own gravity to slingshot cars at a rogue Jaeger. The fact that the robot could even lift its arm, let alone carry the weight of several cars is impressive, and also improbable. The strongest machine – specifically, a crane – that can lift heavy loads is the Taisun Gantry crane, which holds the Guinness World Record and has a load capacity of nearly 44 million pounds – a little over half of what is needed to lift an arm of a Jaeger.

However, robotic movement is not entirely infeasible. Jaegers running head-on at Kaijus or gripping their weapons are motions that can, in fact, be engineered. Through research at Boston Dynamics, scientists designed a dog-sized robot, SpotMini, that can stand, walk, run, recover from a fall and now open doors. Obviously, SpotMini is not the size of a Jaeger, but its invention proves that drastic robotic motion is not an alien concept.

Digging deeper into the issue showed that, hypothetically speaking, some robotic elements of a Jaeger are possible with today’s know-how. But I do have to say, the prospects of seeing a real-life clone of Gipsy Avenger anytime soon are not great.

Our best bet? Hope the next sequel comes out soon.

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