They apply the laws of science in order to provide practical solutions to problems. Mechanical Engineers generally deal with the relations among forces, work or energy, and power in designing systems which will render the achievements of science to the betterment of the human environment. They may work to extract oil from deep within the earth or to send a spacecraft to the moon. They are involved in programs to better utilize natural resources of energy and materials as well as to lessen the impact of technology on the environment. Mechanical Engineers, while strongly oriented towards science, are not scientists.
Science is a search for knowledge.
The science of mathematics extends abstract knowledge. The science of physics extends organized knowledge of the physical world. In each of these, consideration can be limited to a carefully isolated aspect of reality. The Mechanical Engineer, however, must deal with reality in all its aspects. He or she must not only be competent to use the most classical and the most modern parts of science, but also must be able to devise and make a product which will be used by people.