The universe may be dominated by particles that break causality and move faster than light, new paper suggests
Could the cosmos be dominated by particles that move faster than the speed of light? This model of the universe agrees surprisingly well with observations, a pair of physicists has discovered.
In a new paper that has yet to be peer-reviewed, the physicists propose that our universe is dominated by tachyons — a hypothetical kind of particle that always moves faster than light. Tachyons almost certainly don’t exist; going faster than light violates everything we know about the causal flow of time from past to future. But the hypothetical particles are still interesting to physicists because of the small chance that even our most closely held notions, like causality, might be wrong.
The researchers suggest that tachyons might be the true identity of dark matter, the mysterious form of matter that makes up most of the mass of almost every single galaxy in the universe, outweighing normal matter 5 to 1. Astronomers and physicists alike currently do not know what dark matter is made of, so they are free to cook up all manner of ideas —– because, after all, sometimes a far-out idea is right, and even if it’s wrong, it can help us on the path to a better understanding.
The researchers calculate that an expanding universe filled with tachyons can initially slow down in its expansion before reaccelerating. Our universe is currently in an accelerating phase, driven by a phenomenon known as dark energy, so this tachyon cosmological model can potentially explain both dark energy and dark matter at the same time. [Continue reading…]