Mechanics

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In physics, mechanics includes all theories explaining the behaviour of matter. Mechanics can also refer to the practical subjects of creating and maintaining machines.

Each physical theory of mechanics has these three ingredients.

Principles are developed from the knowledge of routine observations and from deliberately planned experiments. As a mechanical theory becomes established, an extensive body of mathematical deduction develops. This yields further opportunities for verification of principles. The mathematical deductions and verifications can address extreme cases. Thus F = ma is true for many problems of engineering while it fails for objects moving at high speeds such as photons.

[edit] Examples

[edit] Unification

As understanding of theories expands, they become unified. Principles are simplified and generalized. For example, the earliest form of statistical mechanics was built upon Newtonian Mechanics with the addition of statistical concepts. That theory yielded the statement PV = NkT; N being the number of molecules of a gas and k the Boltzmann constant. Given Avogadro's number, this equation is equivalent to the Ideal Gas Law. This demonstrates a connection between Newtonian Mechanics and thermal mechanics. PV = nRT is no longer a principle of thermal mechanics but is found to be understandable from Newtonian Mechanics with the addition of statistical concepts.

Unification of theories of mechanics has been a central preoccupation of theoretical physicists. Grand Unification is the problem of unifiying the theories of the four fundamental forces currently known: gravity, strong and weak nuclear interactions and electromagnetic interaction.

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