Produced by: Tarun Mishra
The James Webb Space Telescope (JWST) has provided new data, suggesting that the long-debated "Hubble tension" – the discrepancy in measuring the universe's expansion – may not exist. This comes from recent research led by cosmologist Wendy Freedman from the University of Chicago.
Freedman and her team measured the distances to 10 nearby galaxies using JWST. They found the universe's expansion rate to be 70 kilometers per second per megaparsec, aligning with other major methods related to the Hubble constant.
– The Hubble constant measures the rate at which the universe is expanding. Since 1929, scientists have been calculating this expansion, but agreeing on a precise value has remained elusive. The Hubble constant helps to understand how the universe evolves over time. –
Two methods have traditionally been used to measure the Hubble constant: studying the cosmic microwave background from the Big Bang, which estimates the rate at 67.4 kilometers per second per megaparsec, and measuring nearby galaxies, which suggests 74 kilometers per second per megaparsec.
Freedman, based on JWST data and using three independent methods, stated that there is no strong evidence for Hubble tension. This implies the standard cosmological model of the universe's evolution is still robust.
One approach to determining the expansion rate is by analyzing the light left over from the Big Bang, known as the cosmic microwave background. This method has provided a lower estimate of the Hubble constant compared to local measurements.
The second method focuses on galaxies within Earth's cosmic neighborhood, using specific stars to calculate distances. Earlier measurements using this method yielded higher expansion rates.
Resolving the Hubble tension could have profound implications for fundamental physics and modern cosmology, helping scientists better understand the universe's expansion and the potential fate of cosmic evolution.