Last week, I wrote about seeds — the many varieties of those on land and also those that are found near the water or even underneath it. I also wrote about the many ways that seeds travel: by gripping onto clothing or flying through the air, or by floating.
As I previously described, seeds can float through a number of tricks, including being lightweight, having spindly appendages that spread out their weight and having oily droplets or air sacs to buoy them up. These are all tricks not just used by seeds but also by a whole slew of other plants and animals. There are water striders whose tiny foot pads leave giant shadows beneath shallow ponds and puddles. And there are water birds — all types of gulls, ducks, terns and the innumerable geese we see at this time of year — that are somehow able to fly through the air and also float on the surface. This dual ability takes advantage of a couple of key adaptations like having lightweight or hollow bones and lots of feathers that they can either sleek back in flight or fluff up to make a series of tiny little air pockets while afloat. If you have ever eaten duck, you’re likely aware that there is also a nice layer of fat just underneath the skin, which aids in flotation.
Floating is a type of perfection. It requires a precise balance of weight and form that many creatures have perfected. This perfection has the appearance of simplicity, but people who have attempted to design floating objects or crafts know otherwise. One of my favorite experiments to do with students when I worked in environmental education was called “sink or float.” This was a way to learn about plankton, some of the tiniest floating living things, that have some of the most varied and intricate designs. These designs determine whether a plankton sinks or floats and also how quickly it can travel up and down in the water column. The challenge was for students to take the same object that would naturally sink — like a small rubber ball, for example — and attach a bunch of things to it to get it to float. There are many varieties to this experiment, including creating sinking “races” to see how to make an object sink as slowly as possible. All of these experiments play with the basic concept of buoyancy — what makes an object float.
In an effort to float, people have designed many different types of crafts over history. From carved-out, wooden kayaks to inflatable, rubber boats to ocean freighters, each type of craft uses a different combination of features to float. The aim, in every case, is to allow humans, who don’t naturally float on top of the water all that well, to do just that. This has allowed for freight to be shipped around the world, people to travel across the seas, fishermen to harvest seafood and just the simple enjoyment of the feeling of floating.
I have never been a good floater and always struggled to take on the right posture in the water in order to achieve what looked like such a relaxing thing: floating on your back. Maybe that’s why I usually prefer to swim under the water. Nonetheless, I can appreciate the feeling of floating, whether on the surface or underneath, and its ability to bring a sense of calm. This has been capitalized upon by companies that offer “flotation therapy” where you can float in a tank of salt water that is either open or closed depending on your preference. The purpose of the closed tank is to decrease your sensory input and help you to more fully relax. Benefits are supposed to include pain reduction, better sleep, decreased stress and a better mood.
Watching a raft of fall geese bob up and down, I wonder if they feel less anxious as they float. Regardless, the ease with which they achieve this delicate balance is impressive and humbling.
Susan Olcott is the director of operations at Maine Coast Fishermen’s Association.
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