WENDY FREEDMAN looks down into space. For 40 years, she has delved into the universe’s greatest secrets, patiently tweaking uncertainties to find the numerical values that define its expansion, determine its age, and seal its ultimate fate. rice field.
Friedman at work at the University of Chicago, studies the Hubble constant, a number that describes how fast the expansion of the universe is accelerating. This escalating expansion has been known to American astronomer Edwin since 1929 when Hubble discovered that the farther away a celestial body is, the faster it appears to be moving away.
That’s when things got tricky. Determining numbers requires accurate measurements of astronomical distances. In Hubble’s time, astrophotography was taken by shining light onto a photographic plate through a telescope. Calculating distances from these images was difficult and inaccurate.
In the 1980s, when Friedman was completing his PhD, digital photography was poised to revolutionize astronomy as a whole, and the measurement of the Hubble constant in particular. “That really spurred me on,” Friedman says. Since then, her work has been key to the development of the Hubble tension, a puzzling way in which the two main methods of measuring the Hubble constant give different values.
Now that Freedman has been working on this problem for decades, something interesting is happening. Her latest results suggest that everything is fine after all. If so, decades of pointless work searching for new physics that could explain this discrepancy would be ruined. Luckily, Friedman isn’t afraid of a little controversy.
Hubble constant…
