Fermions: Seeds That Survive a Cosmic Singularity ✎ express

The end of the Universe is not just the fading of light. If dark energy, the mysterious substance accelerating cosmic expansion, tears it apart in a Big Rip scenario, or if expansion reverses into a contraction that pulls everything back to a point like a big bang in reverse, a singularity arrives: a moment where familiar physics breaks down. Here, spacetime curvature and density become infinite, and our theories lose predictive power. For a long time, it was thought that everything vanishes without a trace in this cosmic fire. But the equation derived by Paul Dirac in 1928 to describe relativistic electrons showed a surprising asymmetry: particles of matter (fermions, such as quarks and electrons) are like seeds that do not burn, while force carriers — bosons (e.g., photons, quanta of light)—are flames doomed to die out.

In the very heart of the singularity, where spacetime curvature reaches infinity, the Dirac equation, a mathematical framework combining quantum mechanics and special relativity, yields finite, well-behaved solutions for fermions. In other words, their wave functions remain regular even at extreme curvature. For bosons, which obey different equations (e.g., Klein–Gordon), no such loophole exists: their solutions diverge, predicting destruction. Researchers first spotted this loophole by merging Dirac's ideas with Stephen Hawking's work on black holes — regions where a singularity is hidden behind an event horizon. The analysis showed that near a singularity, fermionic fields can preserve information, unlike bosonic ones.