Physical Laws and Theories

There are huge numbers of physical laws of changeable degrees of complexity and detail, example, laws of motion, of nuclear interactions, of electromagnetism, and so on. Though cutting across such laws there exists basic general principles that all the laws seem to obey. Illustrations are the principles of conservation, certain qualities of equilibrium, the common form of quantum-mechanical principles, and so on. Physical laws and theories are basically strategies for systematizing facts of experience and examination to allow predictions about the future, and design of devices to fetch about the effects one wants. Few physical theories even have the capacity and power to recommend new discoveries.

“Conservation” law inhabit a central place in many regions of physics; they imply the existence of a property or amount that remains unchanged in time even as the system undergoes a huge number of changes in its state. Illustrations of such conserved properties are momentum, mass, angular momentum, energy, charge, and so forth.

There is a hierarchy of laws! For illustration, Newton’s “laws” of motion and the “laws” of thermodynamics inhabit a higher level in terms of universality and comprehensiveness; there are other principles, loosely termed as “laws”, that are of limited applicability.
Such involve:

• Constitutive associations in continuum mechanics,
• Flux-gradient associations of transport phenomena: Fick’s laws, Newton’s law & Fourier’s law, and
• Empirical gas laws, like Joule’s law, Boyle’s law, Joule-Thomson law, Charles law, and so on. That is all consequences of the ideal gas law.

It will be observed that nearly all such statements are associated to properties of matter. Roger Penrose has a random classification of three big categories of fundamental physical theory: superb, useful and tentative. To qualify as “superb”, he deems in essential that the theory must apply without negation to the phenomenon of the world, though also needs that the variety and accuracy with which it applies must, in some suitable logic, and “phenomenal”. Under this group, he lists Euclidean geometry, quantum theory, Newtonian mechanics, Maxwell’s electromagnetic theory, Einstein’s theory of general relativity, and quantum electrodynamics (QED).

Under “helpful” theories, he lists the Gell Mann-Zweg quark model for hadrons, the Glashow-Salam-Ward-Weinberg theory for leptons, and the big-bang theory for the foundation of the universe. Nearly all others he categorizes as “tentative”. The significant distinction among the helpful and tentative categories is the lack of any important experimental support for the theories in the latter group.

It is, obviously, possible for a tentative theory to develop into the helpful category, and even into the superb category. It is not too astonishing that the main superb theories are early ones that have indeed developed over the years from tentative starting.

Albert Einstein said: “A theory is more remarkable – the greater is the simplicity of its premise, the more dissimilar are the types of things it associates, and the more extended its variety of applicability. And hence, the deep impression that classical thermodynamics prepared on me. It is the only physical theory of universal content which convinced, within the framework of the applicability of its fundamental concepts, will never be overthrown”.

Arthu Eddington state “The laws of thermodynamics control, in the last option, the increase and fall of political systems, the freedom of bondage of Nations, the movements of commerce & industry, the beginning of wealth and poverty, and the common physical welfare of the human race”.