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Elaboration:
Physical research largely follows the scientific method, which is based on setting up hypotheses to explain a phenomenon. These hypotheses are then used to make
predictions about the outcome of new experiments or observations, and depending on the outcome of these experiments, the hypothesis will either be rejected or
retained. Since physics is a quantitative science, the theories are formulated expressed in mathematical concepts; certain disciplines such as string theory are
today rather a middle ground between physics and mathematics. Physicists must also – depending on the field – have good knowledge of statistics, partly to analyze
results from experiments, but also to be able to describe large complex systems. Although physicists often use sophisticated mathematical methods, it is often possible
to get a long way by just using dimensional analysis, which is basically the realization that one physical quantity – such as mass or length – is not readily
exchangeable for another; a sentence like "this rod is five kilograms long" seems to be pure nonsense, but if you know that a rod made of that material and with that
diameter has a mass of ten kilograms per meter, it is easy to switch between mass and length, and see that if the rod has a mass of five kilograms, it is half a meter
long. For the most part, dimensional analysis is applied to more complex systems, and can then be a good help to, for example, be able to say which parameters are
important or unimportant. Physics (from the Greek fysykos, physikos meaning "natural" or from the Latin physica meaning "the science of nature") is the science of how nature works at the most
fundamental level. From the beginning, the word "physics" was a collective name for all natural sciences such as chemistry, biology and earth sciences. The development
then led to the division of natural science into the disciplines we know today. Simply put, physics as a scientific discipline deals with different forms of energy
and transformations between these forms of energy. Today, physics deals with the constituents that make up matter and the fundamental forces that affect these
constituents and how matter moves through spacetime. Physicists study these problems at all levels, from the smallest constituents at the subatomic level in
high-energy and nuclear physics to the structure of the universe at the very largest scale in cosmology. In between are research fields such as atomic and molecular
physics, condensed matter physics and space and astrophysics. At a more abstract level, physics can be said to be formulated in terms of symmetries and conservation
laws of energy, momentum, charge and parity. This connection, between symmetries and conserved quantities, is described by Noether's theorem which is a fundamental
theorem in theoretical physics.