Scientific knowledge is one of the most powerful forces in the development of human civilization. Nevertheless, science is often considered inherently impractical because the primary purpose of scientific inquiry is simply to better understand all aspects of the natural world, regardless of whether this understanding will actually influence the reality of day-to-day life. Applied science, however, converts abstract scientific knowledge into the technology that has transformed, and that continues to transform, all aspects of human society.
The discipline of science commonly referred to as physics encompasses a vast array of theories and laws related to the interactions between matter and energy. Newton's three laws of motion are the foundation for the analysis of moving objects, such as trains, cargo ships and billiard balls. Motion in outer space is not significantly influenced by friction or terrestrial gravitation, and it thus provides a particularly clear demonstration of the practical value of Newton's concepts and mathematical relationships. Newton's laws are the fundamental principles that have guided spacecraft to the moon and even into distant reaches of the solar system. Newton's second law, for example, accurately predicts the acceleration that will result from the force generated by a rocket engine.
Electricity from Chemicals
The field of chemistry is concerned primarily with the physical properties of matter and the ways in which different types of matter interact, especially in relation to chemical reactions. A chemical reaction occurs when an energy source stimulates existing substances to react in a way that creates different substances and, in some cases, different types of energy. Chemists can create a remarkable variety of useful materials and devices by applying the principles that govern chemical reactions. Typical lead-acid batteries, for example, generate electrical energy through a chemical reaction involving lead, lead dioxide and sulfuric acid.
The Science of Solar Power
One of the more abstract scientific disciplines is quantum physics, which explores the mysterious properties and interactions of the infinitesimal particles associated with matter and energy. But even this esoteric branch of science has yielded important practical applications. For example, one of the foundational experiments in quantum physics involved the photoelectric effect, which refers to the ejection of electrons from a metal surface illuminated by certain wavelengths of light. Quantum theory provided an explanation for the details observed in this experiment, and this improved scientific understanding of the photoelectric effect eventually contributed to the technological development of digital cameras, computer monitors and solar cells that efficiently produce electricity from the energy in sunlight.
Microbiology is the study of the fascinating microscopic creatures that are found everywhere from frozen tundra to the human digestive tract. Numerous practical applications have resulted from scientific investigation into the structure, reproduction, metabolism and environmental adaptation of microorganisms. Cheesemaking, for instance, has been revolutionized by the knowledge and techniques that allow microbiologists to isolate and mass-produce the particular strains of bacteria responsible for the textures and flavors of different types of cheese. These formulated microbial cultures enable cheesemakers to produce cheese with consistent, desirable characteristics. while also ensuring that delicious cheese can be made from pasteurized milk, which lacks native cheesemaking bacteria. Microbiological research has also contributed to the creation of medicines, the development of new treatments for human digestive disorders and a deeper understanding of soil fertility and plant health.