Driving Questions: So, how does any of this relate to motion? During my research experience, I helped with a project studying how microscopic aggregates fall in water. Sometimes the researchers would use synthetic particles, and other times they would use real phytoplankton! The project was headed by both mathematicians and marine scientists, and the ultimate goal was to understand more about the behavior of particles in the ocean. Can we know exactly how a particle falls? What about an entire cloud of particles? If such a particle transports carbon from the atmosphere to the bottom of the ocean, can we understand more about carbon sinks? If we know about carbon sinks, are there ways in which we can accelerate it so that less carbon is in the atmosphere? While these questions may sound lofty, they’re at the heart of what drives the research.
Setup: In performing the experiments, the researchers used tools like high-speed cameras, water-tanks, microscopes, and Matlab. To simulate the conditions found at different depths of the ocean, they even found ways to have differing salinities throughout the water tank! Some of the tanks contained distinct layers with water of different salinities, while some had a linear density gradient, meaning that the salinity increased slowly throughout the tank. The demo to the left should give you a sense of the experiment’s setup!
Modeling: Coming up with a model of how the particles fall is very similar to the topic of one-dimensional motion. As you’ll learn about shortly, one-dimensional motion is all about time versus displacement from an origin; in the case of this project, we have time versus depth in a tank! Thus, though the physics and mathematics might be much more complicated, the problems have similar origins. After you’ve learned more about the motion, you’ll do your own experiment, but with cars instead of particles!