The cosmos may be fueled by the absurd: a new theory suggests the universe's expansion could be a cosmic 'fuel' that was once dismissed as nonsensical.
For decades, black holes were ridiculed as a cosmic joke. In the 1930s, astronomer Arthur Eddington mocked the idea that a star could collapse into an extreme black hole, calling it absurd. Fast forward to today, and the conversation has taken a dramatic turn. A recent peer-reviewed study argues that black holes might be linked to dark energy, the mysterious force driving the universe's accelerated expansion.
From Absurd to Avoidable
Black holes have evolved from mathematical concepts to observable realities over the past century, thanks to advanced instruments and persistent scientists. Stephen Hawking popularized them in physics, but the debate about their inner workings remains. This historical skepticism is crucial, as it influences the rigor of current scientific claims.
Understanding Dark Energy
Dark energy is the term scientists use for the unknown force causing the universe's rapid expansion. It's like an invisible 'pressure' pushing space outward, despite gravity's tendency to pull things together. This phenomenon is significant, as dark energy constitutes approximately 70% of the universe, yet its composition remains a mystery.
The Key Idea: Cosmological Coupling
The study introduces the concept of cosmological coupling, suggesting that a black hole's effective mass can increase as the universe expands, even without actively consuming stars or gas. This growth is essential because it can mimic the effects of dark energy. Researchers, including Kevin Croker, propose that black holes containing 'vacuum energy' could contribute to the observed acceleration of the expanding universe.
Testing the Theory
The team tested this idea using data from the Dark Energy Spectroscopic Instrument (DESI), a project mapping the universe in 3D by tracking millions of galaxies and their light distribution. This approach is akin to using a cosmic survey to measure the universe's 'stretching' over time.
In their paper, scientists compared the expansion history to the birth of black holes, primarily from massive star collapses. Gregory Tarlé described this as a reverse 'Big Bang,' where black hole formation could be linked to rising dark energy levels.
Potential Impact and Future Steps
If this theory holds, it would provide a concrete origin story for dark energy without inventing entirely new physics. It would also connect abstract cosmic questions to the tangible life and death of stars. However, significant questions remain. Brian Cartwright and Rogier Windhorst note that the strongest signals come from black holes born later in the universe's history, and researchers must determine their current locations and movements over billions of years.
Related research includes the team's earlier work on black hole growth in dormant galaxies, published in 2023, along with the DESI-based press release and the paper preprint for detailed insights.
The main study was published in the Journal of Cosmology and Astroparticle Physics.
