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Pioneering Astrophysicist Jeremiah Ostriker Dies at 87
Jeremiah Ostriker, a celebrated astrophysicist who spearheaded a transformation in humanity’s perception of the universe, unveiling a more expansive and mysterious reality governed by unseen forms of matter and energy, passed away on Sunday at his home in Manhattan’s Upper West Side. He was 87 years old. Ostriker’s revolutionary insights into dark matter and galaxy formation have left an indelible mark on the field of cosmology.
His daughter, Rebecca Ostriker, stated that the cause of death was end-stage renal disease.
For over forty years, primarily at Princeton University, Dr. Ostriker’s research redefined our comprehension of galaxy formation and evolution. His investigations encompassed pulsars, the influence of black holes on the cosmos, and the fundamental components of the universe.
Before the 1970s, the prevailing view among astronomers was that galaxies primarily consisted of stars.
David Spergel, president of the Simons Foundation, lauded Dr. Ostriker as “arguably the most influential individual” in convincing the astronomy community of the inaccuracy of this long-held assumption. In his 2022 nomination of Dr. Ostriker for the Crafoord Prize, astronomy’s equivalent to the Nobel, Spergel, a former mentee, highlighted Dr. Ostriker’s “compelling advocacy for the then-radical new paradigm where visible stars were merely a minor constituent at the core of a significantly larger halo of dark matter with an unknown composition.”
Revolutionizing Galactic Understanding
Dr. Ostriker’s contributions, according to Spergel, represented “the most significant revision in our understanding of galaxies” in half a century.
Known as Jerry to friends and colleagues, Ostriker was recognized for his sharp wit, gentle yet commanding voice, and intellectual curiosity. He embraced data and scientific calculations, fearlessly challenging established assumptions while maintaining a playful spirit. A photograph displayed in his home captured him during a California sabbatical, riding a moped with a wine bottle – a testament to his zest for life.
James Peebles, Nobel laureate in physics and Princeton colleague, remarked on Ostriker’s “quickest wit of any scientist I have encountered” and his unmatched ability in spontaneous debates.
In a 1988 interview, when questioned about his inclinations towards specific cosmological models prevalent in the 1970s – concerning the universe’s finiteness, infiniteness, origin, or ultimate fate – Ostriker stated his lack of preference.
“Scientists have adhered to their biases, and my primary bias at the time was disdain for those with rigid models,” he explained. “How could they possess such certainty when the evidence remained ambiguous and inconclusive?”
Early Life and Education
Jeremiah Paul Ostriker was born on April 13, 1937, in the Upper West Side of Manhattan, the second of four children. His father, Martin Ostriker, owned a clothing business, and his mother, Jeanne (Sumpf) Ostriker, was a public school educator. Famously, baseball legend Babe Ruth resided nearby, and the Ostriker children would often pursue his car for autographs.
“I must have embodied the quintessential nerd child,” Dr. Ostriker wrote in a 2016 memoir for the Annual Review of Astronomy and Astrophysics. His fascination with science ignited at age four when his mother began reading science books aloud to encourage him to sit still for a portrait, sparking a lasting interest.
Following his graduation from the Ethical Culture Fieldston School in the Bronx, Jerry Ostriker attended Harvard University, initially intending to study chemistry. However, he transitioned to physics, drawn to its “cosmic perspective,” as he described it.
“I likely dedicated more time to literature than science,” he admitted in the oral history interview, reflecting on his undergraduate years.
During this period, he frequently visited Alicia Suskin, a former classmate and aspiring artist and poet, at Brandeis University. They married in 1958 while still undergraduates.
Alicia Ostriker, now an emerita professor of English at Rutgers University, became an acclaimed poet, often incorporating her husband into her poems. He, in turn, found poetic resonance in astrophysics. “Astrophysics provides a unique perspective on humanity,” he noted, portraying it as “toiling on this minute grain of spinning sand.”
Besides his wife, Alicia, and daughter Rebecca, Dr. Ostriker is survived by two other children: Eve Ostriker, an astrophysicist at Princeton, and Gabriel Ostriker, a data engineer; a sister, Naomi Seligman; two brothers, Jon and David; and three grandchildren.
After graduating from Harvard in 1959, Dr. Ostriker spent a year at the United States Naval Research Laboratory before pursuing graduate studies at the University of Chicago. He divided his time between the Yerkes Observatory and the physics department, working under Subrahmanyan Chandrasekhar, a future Nobel laureate.
He earned his Ph.D. in 1964 and completed a postdoctoral year at the University of Cambridge, interacting with future black hole luminaries like Stephen Hawking and Martin Rees. Subsequently, Dr. Ostriker joined Princeton as a research scientist, where he remained for 47 years, progressing to chairman of the astronomy department and provost of the university.
Unveiling the Dark Universe
At Princeton, Dr. Ostriker authored influential papers that steered astronomy towards the investigation of the “dark side” of the universe.
He questioned whether galaxies, like stars, could disintegrate if they rotated too rapidly. This question was particularly pertinent to disc galaxies, such as the Milky Way, characterized by a central bulge and a thin, flat disc of stars.
Collaborating with Dr. Peebles, he developed a computer simulation revealing the instability of disc galaxies. Their findings suggested that these galaxies would collapse unless stabilized by an unseen component – a halo of invisible mass providing gravitational support.
This elusive substance, termed dark matter, could consist of faint stars, black holes, rocks, or exotic subatomic particles originating from the Big Bang. Its quantity could be substantial, potentially ten times the mass of ordinary matter.
This marked one of the initial theoretical arguments for the existence of more to galaxies than visible starlight. In the 1930s, astronomer Fritz Zwicky had proposed the concept of “dark matter,” but his idea was largely disregarded until Dr. Ostriker and Dr. Peebles published their groundbreaking paper in 1973.
Dr. Ostriker recalled that the scientific community’s reaction was predominantly skeptical. “I didn’t quite understand why,” he commented, “It seemed like a straightforward conclusion.”
Expanding on this research, a year later, he and his colleagues incorporated data from galaxy clusters and other star systems, asserting that the majority of mass in the universe was indeed invisible.
By the early 1980s, dark matter became a widely accepted element of cosmology. However, paradoxes remained, notably calculations indicating stars older than the universe itself.
Dr. Ostriker and theoretical physicist Paul Steinhardt proposed in 1995 that the missing element was the cosmological constant, a concept Einstein introduced in 1917 but later dismissed as a mistake.
Dr. Steinhardt recounted their conviction that observations couldn’t be explained by a universe solely composed of dark matter and ordinary matter. However, incorporating the cosmological constant resolved these discrepancies.
Other cosmologists, including Michael Turner and Lawrence Krauss, independently advocated for reinstating the cosmological constant. Dr. Turner described Jerry Ostriker as a “giant in the field” and valued their intellectual sparring as a “privilege and often a learning experience.”
Three years later, astronomical teams independently confirmed the accelerating expansion of the universe driven by “dark energy,” manifesting as the cosmological constant and propelling galaxies apart. Consequently, the cosmological constant became integral to the standard cosmological model, aligning with Dr. Ostriker’s earlier predictions.
Furthermore, Dr. Ostriker and collaborators revolutionized the understanding of interstellar space through additional publications.
In 1999, Dr. Ostriker and Renyue Cen posited that most ordinary atomic matter in the observable universe existed invisibly as intergalactic gas, heated to millions of degrees by shock waves and cosmic explosions.
Enduring Passion for Discovery
At Princeton, Dr. Ostriker played a crucial role in establishing the Sloan Digital Sky Survey, a collaborative project between Princeton, the University of Chicago, and the Institute for Advanced Study, aimed at digitally mapping the entire sky using a dedicated telescope at Apache Point Observatory in New Mexico.
He predicted in 1991 that the survey would “increase our knowledge and understanding of the universe a hundredfold.” He elaborated, “The map won’t reveal the universe’s origin, but it will illuminate the nature and source of large-scale structure, the most compelling question in astrophysics today. Answering this will significantly aid our understanding of cosmic origins.”
Launched in 1998, the Sloan Digital Sky Survey is currently in its fifth phase, having produced approximately 10,000 research papers and archived data from half a billion stars and galaxies, freely accessible to astronomers worldwide.
As provost, Dr. Ostriker championed the expansion of Princeton’s financial aid program, converting loans to grants and enhancing accessibility to a Princeton education. In 2000, President Bill Clinton awarded him the National Medal of Science.
Dr. Ostriker retired from Princeton in 2012, coinciding with his daughter Eve joining the astronomy faculty. He then assumed a part-time position at Columbia University, returning to his childhood neighborhood.
“Growing up in New York City, I couldn’t observe the stars,” he once mentioned. Yet, he discovered them, alongside a vast realm beyond ordinary sight, with or without city lights.
This passion remained undiminished throughout his life. In a recent sidewalk encounter, Dr. Ostriker eagerly described a promising new theory of dark matter to a reporter.
In early 2023, despite declining health, he continued his research remotely, maintaining contact with colleagues via email and regular pizza lunches.
Upon learning of James Webb Space Telescope results seemingly supporting his dark matter theories, he emailed colleagues, “Keep up the good work.”
The dark universe he helped conceptualize fifty years prior has shown minor inconsistencies, prompting new theories about dark matter’s nature.
“It’s a highly specific and clear theory. Consequently, it can be proven wrong, which is essential for scientific progress,” Dr. Ostriker remarked in a recent interview. “We are finding it is slightly inaccurate, but not fundamentally flawed.”
Cosmologist Martin Rees summarized Dr. Ostriker’s career: “Some scientists pioneer novel ideas; others refine established concepts. Jerry belonged to the former.”
“He authored early, foundational papers on pulsars, dark matter, galaxy formation, and cosmology. His prolific output continued into his 80s,” Dr. Rees added. “He enthusiastically embraced new data and computational methods. He inspired young researchers and collaborators globally, not just at Princeton.”