Cosmic Voids May Contain the Universe’s Best Secrets

Key Takeaways

• Nature abhors a vacuum, so the saying goes, but nobody told the universe.
• Space is filled with cosmic voids—vast regions mostly free of matter that have opened between dense threads of material that make up a cosmic web.
• Far from being vacant backwaters with little to study, these voids may hold solutions to some of the most persistent cosmic mysteries, such as the behavior of gravity, the nature of dark energy, and the so-called Hubble tension, an observational mismatch in the expansion rate of the universe that has caused astronomers’ headaches for years.
• “With voids, we have the power to tackle most of the interesting cosmological riddles,” says Alice Pisani, a research professor in cosmology working at the Centre for Particle Physics in Marseille (CPPM) of the French Centre for Scientific Research.
• She adds that because there’s less interference from matter, there’s a “high signal-to-noise” ratio in terms of what researchers can observe.