ickerelativistisk

Ickerelativistisk is an adjective used to describe theories, models, or approximations in physics in which the effects of relativity are neglected. In practice, this means calculations assume velocities much less than the speed of light and gravitational fields are weak, so predictions align with Newtonian mechanics or the non-relativistic form of quantum mechanics rather than with full relativistic theory.

The term is typically used in Scandinavian languages, where the standard spelling is often icke-relativistisk or icke-relativistisk, sometimes appearing without a hyphen as ickerelativistisk. It denotes a regime or approximation rather than a fundamental theory, and it is common in contexts such as introductory quantum mechanics, solid-state physics, and low-energy physics.

In quantum mechanics, the non-relativistic framework is represented by the Schrödinger equation, which serves as the cornerstone for many problems in atomic, molecular, and condensed-matter physics. The non-relativistic limit of relativistic equations (for example, the Dirac equation) leads to corrections such as the Pauli equation, which incorporate spin and magnetic interactions but still neglect high-velocity relativistic effects.

Limitations of the non-relativistic approach are clear: it omits time dilation, length contraction, and mass-energy equivalence, and it breaks down at high energies, near-light speeds, or in strong gravitational fields. When such effects are significant, relativistic theories—special relativity, general relativity, or relativistic quantum field theories—are required.

In summary, ickerelativistisk refers to the non-relativistic scope or approximation in physics, valid under low-velocity and weak-gravity conditions, with clear boundaries beyond which relativistic corrections become necessary.