Fluid Dynamics

I'm a total cliche. My little boy is now 10 months old, and it turns out that I'm one of those mothers who goes on and on about how fast time flies and where did the time go? But rather than give another bulleted update on teeth (eight so far, all shockingly visible when he smiles, and I fear that there are early molars on their way) and mobility (no crawling, no pulling up, no cruising, no wanting to take steps, but he can bounce across a room on his backside a la Tigger when he really wants to) I'm going to talk about physics.

Back at LL's six month update, I mentioned that LL was figuring out the basics of physics. He had figured out enough about gravity to keep him upright in a sitting position! He had observed what happened when he hit one object with another! He understood enough about friction that he could pull a blanket to make toys on top of the blanket move towards him! Forces and opposite forces and bodies in motion! All good stuff.

But clearly, I was a bit premature in my assessment of his knowledge. Did you notice anything about what he had learned? It's all good classical mechanics stuff, but there's something notably missing. We are slowly discovering that his handle on fluid dynamics is not quite up to par. Examples:

Picking up applesauce with your fingers doesn't work very well. The applesauce tends to just slide through your fingers. Same with pureed squash. And pureed carrots. And pureed mango. And milk. Every time. If you want to feed these things to yourself, fingers are not a very good mechanism.

Lying on your back and holding a bottle up for yourself is very cool. But when you then roll onto your stomach, with the bottle underneath you (but still in your mouth), you're not going to be able to drink. See how the milk is at the opposite end from the nipple? That's a problem. Sorry, but it's not Mommy's fault. Yell at me all you want, but you will still need to roll onto your back in order to drink. It's not that Mommy is being mean or arbitrary. As they say: it's the Law.

Drinking out of sippy cups is a lot of fun. I understand that it's hard work to drink when there's a valve there, so I've done as you've asked and removed the spill-proof valve, so that the water flows more freely. But when you tip the cup upside down over your head, the water is going to come out. Onto your head. Yes, you're going to get wet. Sometimes the water is even going to go in your eyes. Yell all you want, but don't think that you're going to convince the water to behave any differently.

While we're on the subject of water, let's discuss bathtime. Yes, more than anything else, the bathtub is your own personal fluid dynamics laboratory. It's good that you spend so much time in the tub running experiments and making observations. For instance, I know that you're fascinated to figure out how the spray showerhead works. All those sparkling drops of water, flying out of a shiny metal nozzle! You can't help but want to touch it. But sticking your face there for a closer look? Probably not a good idea for a budding scientist who doesn't like getting his face wet. And doing it over and over and over? Well, I'm going to take that as a sign that you truly are a scientist. Good work.

LL is currently working on a book, LL's Introduction to Fluid Dynamics: A Practical Guide for Infants, with chapters on bottles, sippy cups, straws, pureed food, bathtubs, swimming pools, beaches, and sprinklers. There's also a super-special chapter for boys on what happens when you pee straight up into the air during a diaper change.