IN THE MEDIA: Could faster-than-light particles send messages into the past?

Scientists have long used the hypothetical concept of faster-than-light particles to explore the limits of physics, causality, and time. 

Robert Ehrlich, professor emeritus in the George Mason University Department of Physics and Astronomy, spoke with Popular Mechanics about tachyons, hypothetical particles that would always travel faster than light. If such particles existed, they could theoretically make it possible to send messages into the past, although they have never been observed.  

Ehrlich explained that Einstein’s theory of special relativity prevents particles traveling below the speed of light from being accelerated beyond it because doing so would require infinite energy. However, Einstein did not explicitly rule out particles that had always traveled faster than light. 

The article also discusses Ehrlich’s research into whether neutrinos detected around the 1987 supernova SN 1987A could provide evidence about neutrino mass and the possibility of faster-than-light behavior. His paper is currently available as a preprint and is being submitted for peer review. Ehrlich also noted that most physicists do not believe the available observations show that neutrinos travel faster than light.