This perspective unveils the breadth of human activity on Earth. It spans the globe. An ongoing global effort is the International Space Station. Like any spacecraft in orbit, the people and objects on board will be in free fall. This state of near weightlessness is called microgravity.
Matter behaves differently in a microgravity environment.
Most critical is how gases and liquids will flow through the Station's life support and safety systems. Many believe the Station will also be a platform for microgravity experiments, such as manufacturing computer chips and assembling protein crystals for drugs. Simulations can help scientists understand how heated or cooled fluids behave in microgravity. Computationally reducing gravity, we find that temperature variation on the fluid surface becomes dominant and causes the fluid to move. A few degrees' variation can lead to significant motion.