The twin paradox and the principle of relativity

TL;DR

This paper examines the twin paradox within relativity, emphasizing the role of inertial dragging and presenting new results on cosmic time effects, perfect dragging solutions, and extended Minkowski models to clarify the principle of relativity.

Contribution

It reviews three novel results related to inertial dragging, cosmic time effects, and models avoiding absolute acceleration, enhancing understanding of the twin paradox and relativity principles.

Findings

Cosmic time effect distinct from gravitational and kinematical time dilation

Perfect dragging in an exact Einstein field solution with Kerr spacetime

Extended Minkowski spacetime model to eliminate absolute acceleration

Abstract

In the standard formulation of the twin paradox an accelerated twin considers himself as at rest and his brother as moving. Hence, when formulating the twin paradox, one uses the general principle of relativity, i.e. that accelerated and rotational motion is relative. The significance of perfect inertial dragging for the validity of the principle of relativity is made clear. Three new results are reviewed in the discussion. A cosmic time effect which cannot be reduced to the gravitational or the kinematical time dilation. Perfect dragging in an exact solution of Einsteins field equations describing flat spacetime inside a shell with Kerr spacetime outside it. An extended model of Minkowski spacetime in order to avoid introducing absolute acceleration and rotation through the asymptotic emptiness of the Kerr spacetime.