Encyclopedia of Computer Science and Technology

420 scientific computing applicationstransmitted from a remote location (telemetry). See spaceexploration and computers.Data AnalysisThe analysis of data to obtain theoretical understanding ofthe processes of nature also greatly benefits from the powerof computers ranging from ordinary PCs to high-performancescientific workstations to large supercomputers. Thepossible significance of variables can be determined by statisticaltechniques (see also statistics and computing).The fundamental task in understanding any systemis to isolate the significant variables and determine howthey affect one another. In many cases this can be done bysolving differential equations, where a dependent variablechanges as a result of changes in one or more independentvariables. For example, the classical Maxwell theoryof wave behavior is a system of differential equations thatcould be used to understand, for example, how radar waveswill bounce off an object with a given shape and reflectivity.However, real-world objects have complicating factors:A given problem may include aspects of wave behavior,electromagnetic interaction, deformation of material, andso on. While the great scientists of the late 19th to mid-20thcentury could develop elegant formulas showing key relationshipsin nature, the interaction of many different phenomenaoften requires much more formidable computationthat must be applied to many individual components.It might be considered fortunate that the computer camealong at about the time that it was required for furtherscientific progress. However, another way to look at it isto note that much of the pressure that led to investment inthe development of computers came from that very needfor computational resources, albeit primarily for wartimeprojects.Simulation and VisualizationEven if scientists have a basic understanding of a system,it may be hard to determine what the overall results of theinteraction of the many particles (or other elements) in thesystem will be. This is true, for example, in the analysis ofevents taking place in nuclear reactors. Fortunately computerscan apply the laws of the system to each of manyparticles and determine the resulting actions from theiraggregate behavior (see simulation). Simulation is particularlyimportant in fields where actual experiments are notpossible because of distance or time. Thus, a hypothesisabout the formation of the universe can be tested by applyingit to a set of initial conditions believed to reflect those ator near the time of the big bang.However, even the most skilled scientists have troublerelating numbers to the shape and interaction of real-worldobjects. Computers have greatly aided in making it possibleto visualize structures and phenomena using high-resolution3D color graphics (see computer graphics). FeaturesComputer processing of photographic or scanned data can provide detailed information about our environment. In this NASA test project,aerial and satellite imagery is analyzed to yield information about the ripeness of grapes in a vineyard, as well as moisture, soil conditions,and plant disease. (NASA photo)