It may be popularly known in the construction industry as "mechanical jobs" but this functional name hides an extremely complex and important discipline of engineering.
Working directly with the principles of physics and materials science, mechanical engineers are one of the most broadly trained specialisations in the profession and one of those most critical to modern society.
Throughout their careers, these engineers will work with all things mechanical. Jobs on offer for those trained in the discipline can take people from the depths of the ocean floor to the edges of outer space; as fanciful as this seems, mechanical engineers are the people who design, build and maintain the tools that have thrown our progress exponentially forward since the start of the industrial revolution.
To work in the field, engineers have to demonstrate a solid understanding of some of the central concepts of practical science. Aside from materials science (understanding the properties of different elements and compounds and their practical applications), this includes the fields of mechanics; kinematics; thermodynamics; fluid mechanics; heat transfer; and the principles of all types of energy, from electricity to radiation.
Typical mechanical jobs can range from the utilitarian to the extra-ordinary. Aside from working with the machinery vital to modern manufacturing processes, or with vehicles on all land, air and sea, mechanical engineers work behind the scenes - on heating, cooling and lighting systems - and at the very edge of scientific process.
Perhaps the most famous example of how mechanical engineering is pushing the frontiers of research towards the production of safer, cheaper and more efficient machines is the field of nanotechnology. Working at the very smallest scale of the physical world, mechanical engineering crosses over into the research field of molecular engineering. Though most mechanical jobs have yet to make use of this branch of science as common practice, the field has massively expanded the understanding of materials science. New materials made from nanomaterials such as carbon nanotubes or nanoparticles are being used everyday in everything from electrical storage, solar energy or construction.
Though the width of their expertise can make it hard to reach a single definition of the disciple, mechanical engineering is essentially where science meets the real world. Without their ability to apply concepts from chemical, electrical, nuclear or any other field of research, there would be hundreds of books on science and very little actual technology.
As you can see, 'mechanical jobs' is a remarkably pragmatic way of describing a profession that has had an amazingly profound influence upon the world and is certain to be critical to our way of life for the foreseeable future.