Tyngdkraftsfält

Tyngdkraftsfält, stemming from the Swedish words for gravity and field, denotes the gravitational field surrounding a mass. In physics, a field is a region where a particle would experience a force if placed there. The term is used primarily in Swedish academic and popular science literature to describe what is internationally known as the gravitational field.

Mathematically, the gravitational field g at a point due to a point mass M is described by Newton’s law of universal gravitation: g = GM/r², where G is the gravitational constant and r is the distance from the mass centre. The field vectors point radially towards the mass, and the magnitude decreases with the square of the distance. For extended bodies, the field at a point is the vector sum of contributions from infinitesimal mass elements, which can be calculated via the gradient of the gravitational potential.

In practice, measurements of tyngdkraftsfält are obtained with gravimeters and satellite missions such as GRACE. These data are essential for mapping mass anomalies on Earth, studying ocean circulation, and determining variations in sea‑level rise. In celestial mechanics, the concept underpins the calculation of orbits, the analysis of tidal forces, and the modelling of stellar structure.

General relativity extends the idea by interpreting gravity not as a force but as curvature of spacetime caused by mass–energy. Even here, the familiar Newtonian field emerges as an approximation in weak‑field limits, providing continuity between the classical and relativistic descriptions.

Thorical and experimental investigations of tyngdkraftsfält continue to refine our understanding of mass distribution, climate change indicators, and fundamental physics.