December 9, 2024
Wendy Freedman recognized for pioneering work on Hubble constant measurements
Wendy Freedman, the University of Chicago John and Marion Sullivan University Professor in Astronomy and Astrophysics, was named to Nature’s 10—a list that recognizes key scientific developments over the past year.
Compiled by Nature’s editors, the list highlights notable trends in science, technology, engineering, and medicine.
Freedman was recognized for her work on the cosmic expansion rate, known as the Hubble constant. Scientists have long disagreed on how quickly the universe is expanding, and this year, Freedman released results that bring us closer to a definitive answer.
In the past, two primary methods of studying the Hubble constant—using fluctuations in the cosmic microwave background and measuring the recession of far galaxies—have resulted in conflicting rates.
Freedman specializes in the second method, which requires estimating the distance of far-off galaxies by observing the brightness of their supernovae and calibrating the brightness-to-distance relationship using “standard candles”—well-studied, relatively nearby stars.
In 2001, Freedman led a team that made a landmark measurement of the expansion of the universe using this method, known as the Hubble Key Project. More recently, she pioneered two new methods to use different types of stars to cross-check the accuracy of the measurements.
This summer, she released new results based on readings from the newly launched James Webb Space Telescope, which align with the cosmic microwave background measurements within the margin of error.
“Getting good agreement from three completely different types of stars, to us, is a strong indicator that we’re on the right track,” she told UChicago News. “It looks like our standard cosmological model for explaining the evolution of the universe is holding up.”