Join Cedar Amateur Astronomers on Saturday, May 17 at 8:30 PM as we welcome University of Iowa professor Hai Fu as he presents: "Why Can’t Astronomers Agree on the Universe’s Expansion Rate?"
For nearly a century, humanity has known that we reside in an expanding universe. The rate of this cosmic expansion is quantified by the Hubble constant (H₀), defined as the ratio of a galaxy’s recession velocity (caused by spatial expansion) to its distance from Earth. Astronomers use galaxies as tracers to measure this value, yet even today, they have not reached consensus on H₀—current estimates vary by ~7%, defying expectations of modern precision (1-2%). In this talk, professor Fu will dissect the root of this enduring problem and reveal how local gravitational effects, periodic variable stars, and subtle statistical biases have collectively misled the field.
Go to cedar-astronomers.org/events for more information.
After the presentation, weather permitting, CAA members will be operating several of our large telescopes to view the wonders of the night sky.
