Gliders for EVERYBODY
Above is a picture of Antarctica. Antarctica is as far south as you can get on this planet, and it is where you will find the South Pole. Antarctica is a frozen desert, and is (on average) the coldest, driest, and windiest continent on earth. So why would people want to go there? Not to live, that’s for sure. There are no permanent human residents in Antarctica, though it is always populated with between 1,000 and 5,000 people. What are they there for, then?
Science. Antarctica is largely untouched by human influence, making it an extremely valuable resource for scientists from different countries all over the world. Rutgers University in New Brunswick, New Jersey is making a trip down to this icy desert this winter to do some research of their own. Furthermore, they’ve found a way to continue gathering scientific data while sitting indoors, around a warm cozy fire. This isn’t to say they don’t have to do work, they do. The Rutgers team works many hours a day braving the unforgiving Antarctic conditions. But when they aren’t out there collecting data, their autonomous robot is. Now introducing: The Slocum Glider:
Rutgers has employed a team of these yellow marine robots to continuously patrol the Antarctic waters, constantly gathering information about the surrounding waters. These gliders adjust their density by drawing water in or pumping it out. When the glider is denser than the water around it, it will sink. When it is less dense, it will rise. This is always the case with comparing densities. For instance, observe this experiment:
Egg in Water Glass: A Density Experiment
The glass on the left is filled with fresh water, while the glasses on the right all have saltwater in them. Salt is more dense than water is (imagine standing in a pool filled with salt vs. a pool filled with water, which would you sink faster in?), and so saltwater is also more dense than freshwater. The more salt you add, the denser the water becomes. This is demonstrated above. Notice that the egg in the cup filled with freshwater sinks straight to the bottom, but the egg in the saltwater cup floats near the surface. This is essentially how a glider works. Since the water surrounding the glider does not change in density, the glider can adjust its own density to determine whether it will rise and sink. This way, it can gather information from a variety of different positions in the water. When all is said and done, the glider’s path looks somewhat like this:
Gliders can endure rough conditions. It is much too dangerous for humans to be out at sea during storms, but a glider can go right on gathering information. Think about how much more information you can get with a robot than with people! Robots don’t need to stop to eat or sleep, AND they can be out in the water during storms! Gliders can last on one battery for up to a year. That’s a long time! They do require some cleaning though:
Some sea creatures, like barnacles or mussels, like to use the glider as a home, and attach themselves to it. These can weigh the glider down, and make it harder to control. Glider teams sometimes have to go on missions to recover gliders, and clean them off.
Dave, Jenny and Drew