The effects caused by gravity are not always desirable, however. This is especially true for certain phases of materials processing. Gravity also limits scientists' efforts to study the various processes used in manufacturing and the internal changes to the structure of the material as it reaches its final form. For example, gravity is the driving force behind convection currents between hot and cold regions. These currents mask other events that scientists wish to study and can lower the quality of the final product by causing it to be improperly mixed.
Gravity also causes other phenomena that can mask subjects of interest to scientists.
In a spacecraft orbiting the Earth, gravity is greatly reduced. In this environment, known as microgravity, scientists can strip away the masking effects of gravity and pursue research not possible on Earth. Conducting materials science research in microgravity may eventually lead to improvements in both production methods and final products. Updated January 24, 1996.