Dark matter is the invisible substance that “glues” galaxies together. The composition and physical properties of this mysterious substance still do not give rest to astrophysicists, who are trying to understand it, putting forward new theories. But what if, in fact, dark matter was once ordinary light? This bold hypothesis has been proposed by physicists at Dartmouth University.
Scientists suggest that this invisible substance, which makes up 22% of the mass of the Universe, was formed from high-energy massless particles that suddenly “lost” energy and gained mass after the Big Bang. The results of the study are published in Physical Review Letters.
How did the light get heavy?
According to the new model, dark matter was born in the first moments after the Big Bang, when space was filled with chaotic streams of photon-like particles. They moved at the speed of light, but because of a special interaction – similar to magnetic attraction – they began to pair up. This caused a sudden drop in energy, as if the hot vapor had suddenly turned to ice.
This transition resembles the process in superconductors, where electrons form “Cooper pairs” moving without resistance. It was this analogy that inspired scientists: if electrons can change state abruptly, then dark matter particles can do the same.
Key in cosmic radiation
The theory suggests that traces of this transformation can be found in the cosmic microwave background – the “echo” of the Big Bang. When dark matter particles lost energy, they left a unique imprint in the background that modern observatories can detect.
“We didn’t invent new physics,” emphasizes Guanming Liang, lead author of the study, “Our model is simple and based on already known concepts. That makes it a real test.”
Why did the Universe get “cold”?
This metamorphosis explains why the modern Universe has a much lower energy density than in the first moments after the Big Bang. Liang compares the process to turning double espresso into cold oatmeal: the particle energy is “frozen” into mass, creating the basis for the structure of the cosmos.
The next step is to analyze the cosmic microwave background data. If the theory is confirmed, it would be a breakthrough in understanding the evolution of the universe. “We are closer to solving one of the greatest mysteries of modern physics,” summarizes Caldwell.
This study is a reminder: even in the darkness, the light of the past can lurk.
We previously reported on how dark matter could have existed before the Big Bang.
According to scitechdaily.com
