"Particle" Physics
Elementary "particle" physics is the branch of science, which deals with the most fundamental levels of the physical reality. The theoretical foundation of "particle" physics is Quantum Field Theory, which is a mathematically based theory of high complexity. Quantum Field Theory deals, in a very direct manner, with the fundamental mechanisms be means of which the material universe came, and still comes, into existence.
Since times unknown, philosophers and spiritualists have claimed that, since natural science is only concerned with what is measurable, natural scientists can only have a very limited understanding of reality. This claim may still hold for other branches of science but the accusation has indeed turned obsolete as far as quantum physics goes.
Ever since the late fifties, unmeasurable - and even undetectable - phenomena have been central issues in quantum physics. Theoretical considerations, based on Quantum Field Theory, concerning such phenomena have provided "particle" physicists with numerous clues on what to expect from experiments. Clues that, when tested in high-energy laboratories, eventually turned out to be correct - and thus gave the scientific minded part of humanity a deeper understanding of nature. Quantum Field Theory has not yet yielded a complete understanding of everything, but through the past 40 years a profound model, the Standard Model, of the fundamentals of the physical universe has gradually evolved.
This tour will introduce you to some central concepts connected with the more essential of the unmeasurable phenomena physicists are concerned with these days. Be prepared to enter realms where an atom is as huge as the Earth is huge compared to a human body. On the next page some well-known and quite measurable entities will be presented. For historical reasons these entities are often referred to by the rather misleading name "elementary particles". As will be learned further on, "elementary particles" are neither elementary nor particles.
