Physicist Charles Rosenblatt spends his days defying gravity. In the Liquid Crystal Physics and Complex Fluids lab at Cleveland's Case Western Reserve University, he uses electromagnets to levitate drops of liquid, making them behave as if they had no weight at all. In this way he can simulate conditions on any planet in the solar system, helping NASA engineers prepare for future missions.
Rosenblatt and his team create their antigravity liquid by blending water or glycerol with manganese chloride tetrahydrate powder, which is attracted to a magnetic field. They then take about a twentieth of a teaspoon of the mixture and suspend it between the poles of a powerful electromagnet. The goop settles into a shape resembling a suspension bridge hanging in midair, where the competing magnetic attractions effectively neutralize the tug of gravity. By adjusting the strength of the magnet, Rosenblatt can control the amount of gravitational force acting on the "bridge," thus re-creating the gravity of Mars, say, or the moon. The apparatus also makes it possible to mimic abrupt gravitational changes, such as those that affect a spacecraft when it lands on another planet.
There are also more down-to-earth applications. For instance, the liquid bridge can be used to simulate the behavior of the fluids that coat the air sacs in the lungs. Rosenblatt says his teamcan even model the disorienting acceleration of fluid in the ear that occurs when a person stands up too quickly.
|Magnetic liquid turns from a stiff cylinder to a relaxed blob to simulate different gravities.|
Milind P. Mahajan