Life in the Baby Universe

The Physics of Babies


This article was originally published in Physics World September 2013, copyright IOP Publishing, reproduced here with permission.


I became a first-time father around the same time my postdoc contract ended. My wife had another year to finish her PhD, so I took a sabbatical to be a stay-at-home dad. My months away from research were intended to be full of fun projects. And relaxation. It was to be the Year of Naps – or so I thought.

Unfortunately, while physics problems have solutions that are constant, baby-related problems have solutions that are random and change from day to day. What had worked yesterday will not work today. Maybe it will work tomorrow. This is the gist of the Baby Universe. In this universe, time only means a start and a finish, and contains no information in-between. If the physicist-dad discovers a method to get the baby to eat her breakfast, it is unlikely to work by dinner. This is significant because eating is one of four fundamental dimensions of the Baby Universe, and the same principle of random solutions also applies to the other three: playing, crying and sleeping. (Some scientists consider pooping to be a separate dimension. However, I can assure you that this is always included as part of one of the other four.)

Photo credit : Sarah Perry

The first challenge in my physicist-to-dad transition came with my inability to feed my daughter naturally. My thesis-writing wife’s fresh-pumped milk was in demand and its administration required complex algorithms for its optimal, timely use. Solid food, once introduced, posed a whole new set of problems, as each spoonful required extensive parental coercion. This may have had its upsides: recent research shows that the more you talk to your child, the higher the child’s IQ will be. The fine print that the researchers don’t mention is that this IQ boost comes at your expense, as you must donate those IQ points to the child via non-stop one-way conversations: “Look. Yams. Mmmmm. You like yams. You liked yams yesterday. Oooh, yaaaaaams.”

Later, my daughter acquired a rudimentary ability to feed herself, and the physics of the eating dimension became more complex. If I offer her a spoonful of food, she comes running to see what is on the spoon. If the food is not to her liking, she is scattered like a charged particle from a similarly charged hard sphere. But when, instead, a sticky ball of white rice is presented to her, it triggers a primal urge to make chaos. The “entropy of rice” principle dictates that the dispersion of rice across a 2D “table” is sudden, yet erratic. After adequate time, every grain of rice is scattered into a circle with a radius equal to one baby arm. Given infinite time, it is predicted that babies would not rest until every grain of rice was at every end of the universe.

Photo credit : Debby Shemella (aka Grandma)

As the preceding paragraph indicates, the “eating” dimension of the Baby Universe is closely coupled to the “playing” dimension. Before she could crawl or walk, my daughter would nevertheless want to change her position during playtime. She employed the theory of relativity to satisfy this urge: by moving her playmat from underneath her, she could therefore move herself off the mat. Once mobile, she liked to increase her potential energy by dragging herself up and onto whatever obstacle she could find. If stairs existed, that obstacle was most definitely stairs. This is unfortunate, because although babies understand gravity if they are dropping something (and can even anticipate the “Boom!” the object makes upon impact), they have no comprehension of gravity if they are the body upon which it is acting. It is therefore the physicist-parent’s job to decrease the baby’s potential energy whenever it grows too large, and it is the baby’s work to regain what was taken away.

The PechaKucha talk that started this research

The two remaining dimensions of the Baby Universe — crying and sleeping — are also tightly coupled. To deal with daytime crying sessions, I devised a “terror threat level” system of graded responses, with passivation techniques such as singing, dancing, guitar and something I copied from Monty Python’s “Ministry of Silly Walks”. For inducing sleep, I adopted similarly complex patterns of rocking, bouncing, walking, singing, shushing and waiting. Some of these patterns involved a Swiss ball – a large, inflated exercise ball that serves as a rocking chair for the 21st century. This ball has harmonic degrees of freedom in the side-to-side and front-to-back directions as well as the primary up-and-down one, and is essential for bouncing and rocking a baby to sleep. In addition, it is good for the physicist-parent’s core strength, and can be easily deflated and packed up before relocating for yet another postdoc.

Once the baby is asleep, the physicist-parent is faced with the challenge of escaping the room — in my case over creaky hardwood floors. Doing this before my daughter realizes she is asleep requires knowledge of the “path of least noise”. Once I have exited the room, though, I have a dilemma. No sounds come from the crib. Is my daughter asleep or awake? A measurement is required. As I silently slide on my socks into the dark room, my measurement wakes her and her original state remains unknown. This is Schrödinger’s baby.

My time at home has been a great period in my life and I know I will miss this when I’m back at work. As I write this essay in my head, my daughter rests on my shoulder. Her breathing turns to snoring and I synchronize my own breathing to be in phase with hers. Together we plan all the things I need to do during her naptime. I definitely don’t have time for a nap of my own.

The author and his muse

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