by Breana Cronk, IQS Editor
Last Friday the space shuttle Atlantis launched into its final mission. After almost 25 years and 115 million miles logged, NASA is decommissioning the shuttle as it reorganizes and re-prioritizes. As engineers work to design the new generation of shuttles, researchers turn to a centuries-old device for continued understanding of the effects of gravity and the lack thereof. The centrifuge has been used for decades to test the limits of pilots and astronauts alike. The mechanism creates powerful g-forces, similar to those experienced during liftoff or extremely fast flight, by rotating people and objects at high speed around a central axis in a high speed centrifuge. While these human centrifuges may be the most adrenaline inducing application of the invention, the devices are actually used in the everyday operations of a number of industries.
A large centrifuge capable of moving people and objects at speeds up to 20Gs.
From the medicine in the cabinet to the milk in the fridge or even the oil in the car, centrifuges are essential to modern life and industry. Also known as centrifugal separators, the basic functions and design are relatively simple. An enclosure or arm apparatus is attached to a fixed central axis. Often made of metal or plastic, this is what holds the items to be spun. Spinning is achieved as an attached motor applies force to the perpendicular axis which causes rotation of the arm or enclosure. This creates what is known as centripetal acceleration. More dense particles or substances separate from lighter ones as gravity pulls them out in a radial direction where they collect at the bottom of the tube or holder, while lighter objects move towards the top of the apparatus. In short, the centrifuge allows researchers, scientists and technicians to effectively isolate suspensions by employing the sedimentation principle.
A centrifuge at rest and in motion.
While that explanation may lose the glamour of the NASA centrifuge, it is a precise art that has become integral to many different industrial, commercial and even residential operations. In addition to scientific explorations, industrial centrifuges allow slurries to be dried for water treatment, milk to be separated from whey at dairies around the world and even facilitate uranium enrichment for the generation of nuclear power. Laboratory centrifuges, though much smaller than the aforementioned models are equally impressive. These devices allow doctors and researchers to study viruses, proteins and blood in order to improve the quality of life for millions of people around the world. Centrifuges are even common in clothing dryers. The mechanisms permeate not only the isolated world of research, but the everyday living of many.
Centrifuges are essential not only to our daily life, but to our understanding of the world around us. While the isolation and separation of suspensions may sound unimpressive, it actually provides a tremendous window of opportunity for exploration. As NASA says goodbye to Atlantis and the rest of the shuttle fleet in the coming months, it is important to remember that this closes only one avenue for research. Centrifuges offer a unique opportunity to study the human condition and the world surrounding it on a molecular level.