Nothing can go faster than light. It is a law of physics woven into the very fabric of Einstein’s special theory of relativity. The faster something goes, the closer the prospect of time freezing to a standstill.
Go even faster and you run into time-reversal problems, messing with the concepts of causation.
But researchers from the University of Warsaw in Poland and the National University of Singapore have now pushed the limits of relativity to come up with a system that doesn’t run afoul of existing physics and may even point the way to new theories.
What they have come up with is an “extension of special relativity” that combines three dimensions of time with a single dimension of space (“1+3 spacetime”), as opposed to the three dimensions of space and one dimension of time that we are all used to.
Rather than creating major logical inconsistencies, this new study adds more evidence to support the idea that objects may well be able to go faster than light without completely violating our current laws of physics.
“There is no fundamental reason why observers moving relative to the described physical systems at speeds greater than the speed of light should not be subject to this,” says physicist Andrzej Dragan, of the University of Warsaw in Poland.
This new study builds on earlier work by some of the same researchers who argue that ultraluminous perspectives could help connect quantum mechanics with Einstein’s special theory of relativity—two branches of physics that currently cannot be combined into one a single general theory that describes gravity in the same way we explain other forces.
Particles can no longer be modeled as point-like objects under this framework, as we could in the more mundane 3D (plus time) perspective of the Universe.
Instead, to understand what observers might see and how an ultraluminous particle might behave, we should turn to the kinds of field theories that underpin quantum physics.
Based on this new model, superluminescent objects would look like a particle expanding like a bubble in space – not unlike a wave through a field. The high-velocity object, on the other hand, would “experience” quite different timelines.
Even so, the speed of light in a vacuum would remain constant even for those observers going faster than it, which preserves one of Einstein’s fundamental principles – a principle he had previously thought of only in relation to observers going slower than the speed of light (like all of us).
“This new definition preserves Einstein’s axiom of the constancy of the speed of light in vacuum even for superluminous observers,” Dragan says.
“So our extended special relativity doesn’t seem like a particularly far-fetched idea.”
However, the researchers acknowledge that moving to a 1+3 model of spacetime raises some new questions even as it answers others. They suggest that the theory of special relativity needs to be extended to incorporate faster-than-light reference frames.
This may well involve borrowing from quantum field theory: a combination of concepts from special relativity, quantum mechanics and classical field theory (which aims to predict how physical fields are going to interact with each other).
If the physicists are right, the particles of the Universe will all have extraordinary properties in extended special relativity.
One of the questions raised by the research is whether we could ever observe this widespread behavior – but answering that will require much more time and many more scientists.
“The simple experimental discovery of a new fundamental particle is a Nobel Prize-worthy feat, and it is possible for a large research team using the latest experimental techniques,” says physicist Krzysztof Turzyński, from the University of Warsaw.
“However, we hope to apply our results to a better understanding of the phenomenon of spontaneous symmetry breaking associated with the mass of the Higgs boson and other particles in the Standard Model, especially in the early Universe.”
The research has been published in Classical and Quantum Gravity.