This is a big week for Hollywood: amid a massive writers’ and actors’ strike, two potential blockbusters are opening on the same day: Christopher’s Nolan’s Oppenheimer and Greta Gerwig’s Barbie.
The former portrays a man who reshaped the world through physics. The latter portrays a woman who lives in a world that defies the laws of physics altogether.
Oppenheimer’s world is ours, dictated by physical laws we have studied for centuries. But, what might the physical laws of Barbie’s world look like? This is a natural question for me as a Ph.D. student studying the philosophy of science. But it is also a natural question for me as a Barbie expert—when I was a kid, I played with the dolls much longer than what might be considered “cool.”
For all of philosophers’ inquiries into metaphysically possible worlds, surely Barbie’s pink and plastic universe bears contemplation. Yet when I started to type “Barbie physics” into Google to see who might be pondering this issue, the top recommendation was disappointingly “Barbie physique.” There have been countless discussions of Barbie’s fashion sense, but scant thought into the workings of her universe. Many have pondered Barbie’s iconic makeup but not her universe’s physical makeup.
And while I agree that when it is taken as a standard for our own body, Barbie’s physique can be harmful to someone’s self-image, I think it is important to remember that Barbie herself never claims she is part of our world. In fact, as immortalized in song, we know that she is “a Barbie girl in a Barbie world” (italics added for emphasis), for which the physical parameters would likely differ from our own.
Scientific theorizing often requires us to engage with possibilities never before conceived. In philosophy and theoretical physics, we often employ “thought experiments” to explore the consequences of theories for which empirical verification is impossible. Schrödinger’s cat, Wigner’s friend and the Einstein-Podolsky-Rosen paradox all are examples of thought experiments that have been foundational to contemporary physics. Particularly in cosmology, scientists must theorize at astronomical scales beyond our experimentation. Contemporary cosmologists use models to vary the fundamental constants in order to experiment with other possible universes.
Imaginative play with Barbies does the same thing: generations of children experiment with ways the world could be. In their hypothetical musings, they are engaged in a form of world-building similar to thought experiments or modeling. Playing with Barbies is the opposite of frivolous—as questions regarding the possibility of a multiverse proliferate, that iterative imagining will be essential to our inquiry.
Of course, there are very few data available to us regarding the physical parameters of the Barbie world. It appears to be causally and temporally disconnected from our own, just like the universes posited by some models of string theory. The little information we do have, however, allows us to make fascinating inferences regarding its underlying physical picture.
Barbie, if sized to human scale, would stand at five feet, nine inches and weigh 110 pounds. This is dangerously underweight in our universe. Yet weight is just the measure of the gravitational force with which Earth attracts masses toward its center. Perhaps Barbie’s world has a different gravitational constant, for which her weight would differ. Or perhaps the gravitational differences of the Barbie world caused bodies to develop differently there in the first place. It’s a well-documented phenomenon that astronauts often lose weight in space. In a 2018 interview with Popular Science, Scott Smith, leader of NASA’s Nutritional Biochemistry Laboratory, theorized that weightlessness disrupts the “stretching of your stomach—which sends the signal to your brain to say ‘you’re full, stop eating” so that this signal occurs earlier. Perhaps the Barbie world exhibits similar effects, and her physique is reflective of that.
When we observe animated representations of the Barbie world, it exhibits strange and perplexing physical laws. For instance, in Barbie & Her Sisters in a Puppy Chase, her world demonstrates curious non-Newtonian properties. In one scene, a dog is riding a horse and is jolted upward. Rather than fall back down in the same spot on the horse’s moving back because of the effects of inertia, the dog flies backward while the horse keeps moving forward. This is consistent with Aristotle’s debunked theory of physics, which did not account for the effects of Newton’s first law of motion. (Interestingly, in a talk I attended in July at the Rutgers University, astrophysicist Luke Barnes of Western Sydney University in Australia explained that Nintendo’s Mario and Luigi, too, appear to live in an Aristotelian universe, in which they fall backward even on a forward-moving platform.)
The climatic conditions in the Barbie world also remain unknown. Barbie is often seen driving in her pink convertible with suspiciously perfect hair. Is the Barbie world a world without wind? Wind is caused because air over land absorbs heat from the sun differently than that above water, causing motion. What would this suggest about the air on Barbie’s world—that it absorbs heat evenly no matter where it is or has a constant density? Then there is the Barbie Dreamhouse, a replica of which exists in Malibu, Calif. The Dreamhouse in Barbie’s world doesn’t seem to be subject to wildfire, which would make sense if there was no wind. But the house isn’t earthquake-retrofitted—suggesting the Malibu of the Barbie world has not only different climatic conditions but also wildly different geophysical properties than our own.
The majority of Barbie Dreamhouses display curious architectural features. For one, they are foldable, split in half, with open-facing rooms. This seems to further confirm the hypothesis that Barbie lives in a windless world and furthermore one without precipitation. How the water cycle functions in the Barbie world is a strangely neglected topic, as is the psychological impact of long-term living in these panopticon-style homes.
Barbie, like us, is a carbon-based life-form: plastic is a high-molecular-weight organic polymer composed of 80 percent carbon. Plastic being the primary substrate of life would certainly have interesting consequences, however. One area for future research is the question of whether “life in plastic” is indeed “fantastic,” as the 1997 song “Barbie Girl,” by Aqua, originally claims.
Clearly much work remains to be done to solve the overlooked mysteries of the Barbie universe, and this includes Barbie herself. She is extremely accomplished—at the same time an astrophysicist, engineer and astronaut—not to mention a general “scientist.” To me, this is indicative of her wide-ranging and interdisciplinary approach to science. While many will learn of J. Robert Oppenheimer’s accomplishments through the movie, let’s not forget Barbie’s—her career has lasted 64 years and counting since her debut in 1959, while Oppenheimer merely had about 44 active years in the field.
Regardless, both Barbie and Oppenheimer have influenced popular culture to an extraordinary degree and have been subject to scrutiny, adulation, criticism and praise. Both prompt us to consider the power of envisioning new worlds for good or ill. I vividly remember the day an older cousin told me that, at age 10, I was too old to play with dolls, and no arguments regarding the very sophisticated world-building I was engaged in changed her mind. In our debates about Mattel’s Barbie qua feminist hero or tool of the patriarchy, we’ve lost sight that she’s not just Mattel’s Barbie. She’s mine and my baby cousin’s and yours and your child’s. As long as the kids who play with her, Ken and her ever widening social circle can dream up new worlds, she will be what they make of her. And our world will be, too.
This is an opinion and analysis article, and the views expressed by the author or authors are not necessarily those of Scientific American.
