The concept of dark energy emerged to reconcile observations of distant supernovae. These celestial explosions appeared farther away than expected if the Universe’s expansion were consistent with a purely gravitational model. Physicists theorized that a repulsive force, dubbed dark energy, was driving the acceleration. This idea became a cornerstone of the ΛCDM (Lambda Cold Dark Matter) model, the standard framework for cosmology.
However, recent observations have raised questions about the accuracy of this model. The “Hubble tension”, for instance, reveals discrepancies between the current expansion rate of the Universe and its inferred early expansion from the Cosmic Microwave Background (CMB). Additionally, data from advanced instruments like the Dark Energy Spectroscopic Instrument (DESI) suggest that the ΛCDM model struggles to account for evolving patterns in cosmic structures.
Researchers at the University of Canterbury, led by Professor David Wiltshire, offer an alternative explanation that removes the need for dark energy altogether. Their timescape model proposes that the appearance of an accelerating Universe is an illusion caused by the uneven effects of gravity on time.
The theory hinges on a key principle of Einstein’s general relativity: gravity can distort the flow of time. In regions of space with strong gravitational fields, such as galaxies, time runs more slowly compared to vast, empty voids in the cosmos. These differences in time dilation mean that clocks in galactic regions would measure billions of years less than clocks in cosmic voids.
Previously: Maybe ‘dark matter’ doesn’t exist after all, new research suggests.
I’m no astrophysicist but dark energy and matter always felt a bit like cheats.