Renowned physicist Joel R. Primack, who played a pivotal role in understanding the formation of galaxies and the structure of the universe, passed away on November 13, 2023, in Palo Alto, California. He was 80 years old. His wife, Nancy Ellen Abrams, confirmed that the cause of death was pancreatic cancer.
Primack served as a professor of physics and astrophysics at the University of California, Santa Cruz, where he significantly contributed to the field of cosmology. His groundbreaking work included a landmark paper published in the journal Nature in 1984. This influential study detailed how quantum fluctuations in the early universe led to the formation of galaxies and larger cosmic structures.
At the time of the paper’s publication, scientists acknowledged that ordinary matter, which includes the particles that form stars, planets, and living beings, accounted for only a small fraction of the universe’s mass. Observations of galaxies revealed that their outer edges were spinning at speeds too high for the visible mass to hold them together. This observation led to the hypothesis of dark matter, an unseen substance that exerts gravitational forces.
Even decades later, the exact nature of dark matter remains unknown. However, Primack, along with colleagues George Blumenthal and Sandra Faber, and Martin Rees of the University of Cambridge, identified crucial properties of dark matter that are essential for understanding the universe’s structure.
Saul Perlmutter, an astrophysicist at the University of California, Berkeley, remarked on Primack’s contributions, stating, “That became part of this whole foundation that we’ve been using now for years.” His work laid the groundwork for much of contemporary astrophysics, influencing both theoretical and observational studies in the field.
Primack’s legacy extends beyond his research contributions. He was known for his ability to communicate complex scientific ideas to a broader audience, fostering a greater appreciation for astrophysics. His influence can be seen in the ongoing research that continues to explore the mysteries of the universe, particularly the elusive nature of dark matter.
As the scientific community mourns the loss of Joel Primack, his impact on the field of physics and our understanding of the cosmos will be remembered for generations to come.
