Superluminal phenomena shed new light on time: Graham Shore talks about the research into the possibility that photos can move faster than the speed of light as we know it and whether the existence of such photons would imply that time travel is possible.
Quantum effects such as vacuum polarization in gravitational fields appear to permit "superluminal" photon propagation and give a fascinating new perspective on our understanding of time and causality in the microworld. To understand these new developments, we first need to question the origin of the received wisdom that superluminal motion necessarily leads to unacceptable causal paradoxes.
- "Faster than Light" Photons in Gravitational Fields -- Causality, Anomalies and Horizons
- Accelerating Photons with Gravitational Radiation
- Faster than Light Photons in Gravitational Fields II - Dispersion and Vacuum Polarisation