Instead of a single Big Bang that brought the universe into existence billions of years ago, cosmologists are starting to suspect there may have been a second transformative event that could explain the vast abundance of dark matter in the universe. This intriguing hypothesis challenges our understanding of cosmic origins and opens up new avenues for exploration.
Dark matter is the hypothetical form of matter that doesn’t interact with light or electromagnetic fields in any way, yet it appears to make up roughly 27 percent of the known universe. Astronomers have long grappled with this enigmatic substance, which seems to defy the laws of physics as we currently understand them.
One of the key puzzles related to dark matter is the behavior of galaxy clusters. These massive structures, composed of thousands of galaxies, move in ways that our existing Standard Model of physics can’t fully account for. To make the math work, scientists propose that there’s a significant amount of unseen matter—dark matter—out there. However, despite our best efforts, we’re still unable to directly observe this mysterious substance.
Enter the concept of a “Dark Big Bang.” In a yet-to-be-peer-reviewed paper, physicist Katherine Freese and her colleagues from the University of Texas at Austin propose that this secondary cosmic event may have occurred when the universe was less than one month old. Here are the intriguing details:
Darkzillas: Imagine monstrously sized particles, 10 trillion times the mass of a single proton. These “darkzillas” could have formed during the Dark Big Bang, adding to the pool of dark matter.
Dark Cannibals: Alternatively, if the event was more gradual, it might have produced lighter particles known as “dark cannibals.” These particles would absorb each other upon collision. Interestingly, dark cannibals share similarities with one of the leading dark matter candidates: weakly interacting massive particles (WIMPs).
Freese hopes that studying gravitational waves emerging from the universe’s gravitational wave background could shed more light on her Dark Big Bang theory. These waves, caused by cataclysmic events like merging black holes or neutron stars, carry information about the early moments of the cosmos. By analyzing disturbances in signals from highly magnetized neutron stars called pulsars, scientists aim to pinpoint the origin of these gravitational waves.
This research reflects a broader shift in cosmology. Instead of envisioning a single explosive event that birthed the universe, scientists now consider the possibility of multiple phase transitions. These gradual shifts could have gradually brought everything—from regular matter to dark matter—into existence.
As we continue to explore the cosmos, the Dark Big Bang hypothesis invites us to rethink our cosmic narrative. Perhaps the universe’s story is more complex than we ever imagined, with hidden chapters waiting to be unveiled by the light of scientific inquiry.