https://phys.org/news/2024-03-webb-hubb ... verse.html
by Bethany Downer, Ninja Menning, European Space Agency
The rate at which the universe is expanding, known as the Hubble constant, is one of the fundamental parameters for understanding the evolution and ultimate fate of the cosmos.
However, a persistent difference, called the Hubble Tension, is seen between the value of the constant measured with a wide range of independent distance indicators and its value predicted from the afterglow of the Big Bang. The NASA/ESA/CSA James Webb Space Telescope has confirmed that the Hubble Space Telescope's keen eye was right all along, erasing any lingering doubt about Hubble's measurements.
One of the scientific justifications for building the NASA/ESA Hubble Space Telescope was to use its observing power to provide an exact value for the expansion rate of the universe. Prior to Hubble's launch in 1990, observations from ground-based telescopes yielded huge uncertainties. Depending on the values deduced for the expansion rate, the universe could be anywhere between 10 and 20 billion years old.