There are almost endless mysteries from the dawn of time hanging in the cosmos, and now there might be an answer to one of the most perplexing ones.
Something is twisting light that spawned with the Big Bang 13.8 million years ago. Japanese scientists Yuto Minami and Eiichiro Komatsu now believe this is happening may not have seen the phenomenon with their eyes (more on that in a second), but they think they have seen its effects on the polarization of light in the cosmic microwave background (CMB). Faint remnants of light from the Big Bang still flicker in the CMB. The scientists have come to the conclusion that dark energy or dark matter could have been rotating light particles, or photons, putting an apparent warp in the light.
"This phenomenon is called direct interaction (or coupling) between photons and dark energy or dark matter," Minami, who recently published a study with Komatsu in Physical Review Letters, told SYFY WIRE. "The coupling is Chern-Simons coupling."
Whatever is changing the orientation of photons in the CMB is violating physics. Physics says that everything should look and act the same, even if it is flipped the other way into a mirror image of itself. This is parity. It goes for all subatomic particles and forces in the universe, including gravity, electromagnetism and strong force. Weak force (which is ironically stronger than gravity and brings on decay) is the only force exempt from parity. The warping of photons by something unseen could mean a violation of parity—something physics doesn't agree with is interacting with them. Does it have anything to do with weak force? Nobody knows.
"Twisting, or rotation, has two directions: clockwise and anti-clockwise," said Minami. "If parity is not violated, both rotation happens equally; that means there is no rotation in total. However, if parity is violated, one of the rotation directions is favored. There is a possibility that the parity violation of the universe which happened before the emission of the cosmic microwave background photons creates a similar signal."
This is starting to sound like Star Wars with all the forces involved, but it will make sense.
Minami and Komatsu measured how instruments rotated by using light from the Milky Way. What they could make out from the way the instruments were positioned was that something had disturbed those photons, which were supposedly oriented in a slightly different way when they first emerged with the rest of the universe. However, if no one can see dark matter or dark energy or prove their existence, how can such a bold assumption be made? Their existence and behavior can only be theorized about by physicists with plenty of coffee and doubts until there is proof they exist, and that proof will also make it possible to study them up close like never before. If only it were that easy.
Dark energy is thought to be behind the unusually rapid expansion of the universe. If dark energy really is stretching the universe further than the human brain could ever fathom, some sort of movement must be happening there. The repulsive force of dark energy could be having a direct affect on how light particles are polarized while dark matter could be interacting with another force and having an indirect effect through the way it affects particles that then affect photons. It might be pulling at molecules in the process of expanding the universe that burst out of the Big Bang. The endless stretching of the universe may also affect photons that get screwed around with as a result.
Dark matter, on the other hand, can exert gravity but refuses to interact with light. Whether dark matter interacts with weak force or either of the three other fundamental forces remains unknown. The fact that it won’t touch photons does not cancel out the chance of it interacting with other type of particles. Particles that interact with dark matter could be bumping into photons. There is also a chance that dark matter and dark energy are both directly or indirectly affecting how light in the CMB is polarized, kind of like Darth Vader and Darth Sidious facing down a nervous Jedi with the Dark Side of the Force.
It isn't easy to tell how light in the universe has changed since the Big Bang, and it continues to change, which is something even Minami does not believe can be followed (at least yet).
"It is not possible to see the effects of change during the propagation of the photons in the framework of our search," he said. "We can only see the differences between the point where photons are emitted and the point where photons are observed."
The scientists even think that there could be an unknown type of particle that pushes dark matter, energy or both to cause the warp. It isn’t out of the question when there are already so many unknowns.
So does their find expose the real dark side? Not yet, but it very well could.