The universe’s expansion rate remains one of the most fundamental questions in modern astrophysics. Scientists have been trying to determine this rate for decades, known as the “Hubble constant,” which shapes our understanding of the cosmos and its age.
Adam Riess, a physicist at Johns Hopkins University, has dedicated his career to resolving the Hubble tension, a discrepancy between measurements of the universe’s expansion rate in different parts of space. The tension was first discovered by a team that included NASA and European Space Agency (ESA) astronomers, who used data from the Planck satellite and the Hubble Space Telescope.
Despite significant advances in measuring the Hubble constant with high-precision instruments like the James Webb Space Telescope, the tension persists. Brenda Frye and her team used an innovative method called gravitational lensing to measure the Hubble constant in a different part of the universe.
Their analysis revealed a Hubble constant value that matches measurements in our local universe but is somewhat at odds with values obtained when the universe was young. Riess emphasizes that resolving this discrepancy may require new physics or a revised understanding of dark energy and dark matter.
The cause of the Hubble tension remains unknown, leading some scientists to speculate about the existence of extra dimensions or modifications to gravity at large scales. The search for answers continues with upcoming missions like NASA’s Nancy Grace Roman Space Telescope and ESA’s Euclid mission, offering hope for new insights into the nature of the universe.
Source: https://www.earth.com/news/webb-telescope-confirms-hubble-constant-our-understanding-of-universe-expansion-very-wrong/