2 articles · Updated · The Brighter Side of News · Aug 9
Summary
University of Eastern Finland and Tampere University researchers proposed an accelerating wave equation for light that allows solutions only toward positive time, framing a possible microscopic arrow of time.
The 1+1-dimensional model adds an acceleration term missing from the standard wave equation when wave speed changes, and the team says its behavior resembles relativity through a wave-specific “proper time.”
The framework also revisits the Abraham-Minkowski momentum dispute, arguing light’s momentum stays unchanged in the wave’s own reference frame while apparent shifts in matter are relativistic to outside observers.
In time-varying photonic materials, the equation analytically describes pulses that slow exponentially, gain energy and shorten, with the authors attributing that local effect to an effective curved spacetime.
The work, published in Optica, remains theoretical; proposed tests in radio-frequency lines and epsilon-near-zero materials face losses, thin-material constraints and damage from ultrashort pulses.