The expansion of the universe observed by astronomer Edwin Hubble shows that galaxies are moving away from each other at a speed proportional to their distance. Scientists rely on the Hubble-Lemaitre constant to calculate this speed: fundamental parameter of cosmology.

Mysterious inconsistencies

Recent observations have revealed a discrepancy in the values ​​of the Hubble constant when examining distant regions and closer celestial objects such as supernovae. In remote regions the speed is measured at 244,000 kilometers per megaparsec, while in near-Earth regions it is almost 264,000 km/h per 1 Mpc of distance.

An alternative theory of gravity

Researchers from the University of Bonn and the University of St Andrews suggest that Earth’s location in a region of low-density matter surrounded by a high-density bubble may explain the observed discrepancies. The gravitational forces of this envelope affect the galaxies, causing them to move faster than expected*.

US astronomers made observations by changing the path of light from a distant supernova towards Earth. This allowed them to calculate a new value for the Hubble constant, which opened up a new perspective on the expansion of the universe. Similar observations in the future promise to reveal the reasons for the current discrepancies in the prediction of this important cosmological indicator.