Recent observations indicate that our current models of the universe may be fundamentally flawed, and a surprising solution has emerged: space itself might behave like a viscous fluid. This means the vacuum of space isn’t empty but has a subtle resistance to expansion, potentially resolving discrepancies in our understanding of dark energy.
The Problem with Current Models
For decades, scientists have relied on the Lambda-CDM model, which treats dark energy – the force driving the accelerating expansion of the universe – as a constant, unchanging background energy. However, recent data from the Dark Energy Spectroscopic Instrument (DESI) revealed a slight mismatch between this model and the actual rate at which galaxies are moving apart. This discrepancy suggests that our understanding of dark energy might be incomplete.
A Viscous Universe?
Muhammad Ghulam Khuwajah Khan, a researcher at the Indian Institute of Technology, proposes that space may possess bulk viscosity – a measure of how much a fluid resists flow or deformation. In this case, it means the vacuum of space isn’t perfectly empty but has a ghostly resistance to expansion.
Khan suggests that this viscosity arises from “spatial phonons,” longitudinal vibrations within the fabric of space itself, similar to how atoms vibrate in a crystal. These vibrations would act as sound waves within the vacuum, creating a drag on cosmic expansion. As space stretches, these phonons slosh around, generating pressure that opposes the outward push of dark energy.
How the Model Fits the Data
This model, which treats the universe as a viscous fluid, aligns remarkably well with the DESI data. It offers a potential solution to the observed discrepancies between theory and observation, suggesting that the universe’s expansion may be slower than predicted due to this viscous effect.
Caution: It’s Still Early Days
While promising, this hypothesis remains unconfirmed and requires peer review. If proven correct, viscous dark energy would fundamentally change our view of the vacuum of space. Currently, it’s unclear whether this viscosity is a genuine property of nature or merely an artifact of measurement errors.
“This is not a definitive answer, but a compelling alternative that deserves further investigation,” says Khan.
The hard data from DESI are still being analyzed, and the scientific community remains cautious. However, the possibility that the universe is “stickier” than we thought opens up exciting new avenues for cosmological research.
