Observation of image pair creation and annihilation from superluminal scattering sources

TL;DR

This paper demonstrates that superluminal sources can cause inverted event sequences and image pair creation or annihilation, revealing fundamental limits in deducing event kinematics from imaging alone.

Contribution

It provides experimental evidence of superluminal source effects, including event inversion and image pair dynamics, which were previously unobserved.

Findings

Superluminal sources invert event order.

Image pair creation and annihilation occur at speed interfaces.

Imaging alone cannot uniquely determine event kinematics.

Abstract

The invariance of the speed of light implies a series of consequences related to our perception of simultaneity and of time itself. Whilst these consequences are experimentally well studied for subluminal speeds, the kinematics of superluminal motion lack direct evidence. Using high temporal resolution imaging techniques, we demonstrate that if a source approaches an observer at superluminal speeds, the temporal ordering of events is inverted and its image appears to propagate backwards. If the source changes its speed, crossing the interface between sub- and super-luminal propagation, we observe image pair annihilation and creation. These results show that it is not possible to unambiguously determine the kinematics of an event from imaging and time-resolved measurements alone.