Jeremiah Ostricker, an astrophysicist, helped revolutionize humanity's view of the universe, revealing it is a larger and darker area than we can see, ruled by invisible forms and energy we still don't understand, died on Sunday in his home, west of Manhatan. He was 87 years old.
His daughter, Rebecca Ostriker, said the cause was end-stage renal disease.
For over 40 years, primarily at Princeton University, Dr. Ostricker's work has changed our understanding of how galaxies form and evolve as we explore the nature of pulsars, the role of black holes in the evolution of cosmos, and what the universe is.
Most astronomers before the 1970s believed that galaxies were mostly made up of stars.
David Spergel, president of the Simons Foundation, which supports scientific research in 2022, “is probably the single most important person in convincing the astronomical community that this natural and fascinating assumption is wrong,” nominated his leader, Dr. Ostricker, nominated the Crafford Prize and mentored Nobel's astronomical equivalent award. He cited Dr. Ostricker's “an eloquent defense of the radical new model of the time, in which visible stars in the galaxy were minor contaminants at the heart of a much larger halo of dark matter of unknown composition.”
He said Dr. Ostricar's work was “the most epic revision in understanding the galaxy” for half a century.
Jerry Ostricker was known to his friends and colleagues, so the man with a thorny humor and a soft but commanding voice was willing to go wherever data and scientific calculations led him, and was not embarrassed to question the assumptions. Notably on display at his home was a photograph of himself taken during a California sabbatical, driving a moped with a bottle of wine.
“He had the fastest wit of any scientist I've encountered,” said James Peebles, a Nobel Physics recipient and colleague of Princeton's Dr. Ostricker. On the issue, “And I don't remember matching him with a voluntary argument.”
In an oral history interview with the Institute of Physics in 1988, when he entered the field in the 1970s, he was asked if he preferred one of the universe's models.
“Scientists followed their own biases, and my principled bias at the time was lightly empty and intolerant towards all these people who had a particular model,” he replied. “How can they be so sure when the evidence is confused and decisive?”
“Classic Geek Kids”
Jeremiah Paul Ostreker was born on April 13, 1937, on the second of four brothers, Upper West Side. His father, Martin Ostricker, ran a clothing company, and his mother, Jeanne (Sampf) Ostricker, was a teacher at a public school. Babe Ruth lived around the corner, and the kids chased the car in search of autographs.
“I must have been a classic nerd kid,” Dr. Ostricker wrote in a memoir published in 2016 in the Annual Review of Astronomy and Astrophysics. He began to become interested in science when he was four years old.
After graduating from the Bronx Ethics and Culture Field Ston School, Jerry Ostricker planned to go to Harvard University where he studied chemistry. Instead, he switched to physics. It appealed to what he called his “universal perspective.”
“I probably spent more time on literature than I spent on science,” he said in an oral history interview.
He soon began commuting to Brandeis University, visiting Alicia Suskin, a former Fieldston classmate who was an ambitious artist and poet. They married in 1958, but they were still undergraduates.
Alicia Ostriker, professor of English at Rutgers University, became an award-winning poet and often wrote her husband in her work. He then found poetry in astrophysics. “As an astrophysicist, you get a perspective on humanity,” he said.
In addition to his wife and daughter Rebecca, editor of the Boston Globe opinion section, Dr. Ostricker was survived by Princeton astrophysicist Eve Ostricker and data engineer Gabriel Ostricker, two other children. sister, Naomi Seligman. two brothers, John and David; and three grandchildren.
After graduating from Harvard in 1959, Dr. Ostricker worked for a year at the U.S. Naval Research Institute before enrolling in graduate school at the University of Chicago, splitting time between the university's Yerkes Observatory and the Faculty of Physics.
He received his PhD. 1964. After spending his postdoc years at Cambridge, he rubbed his elbows with future black hole eminences like Stephen Hawking and Martin Reese. He remained there for 47 years, rising ranks and becoming chairman of the Astronomy department and university provost.
The dark side of the universe
In Princeton, Dr. Ostriker wrote a series of papers that led astronomy to the dark side.
He wondered if star-like galaxies could break and fall apart if they were too fast. This issue was particularly relevant to so-called disc galaxies like the Milky Way, with star-like thin yorky centres in fat-shaped shaped circles surrounded by thin, white star flats.
Working with Dr. Peebles, he built a computer simulation and discovered that the disc galaxy is indeed unstable. If there were nothing we couldn't see, they would fall apart, some additional halos of invisible mass, lending gravity support.
Anything like this called dark matter – exotic subatomic particles left from dim stars, black holes, rocks, and big bangs – may have ten times the mass of normal atomic matter.
This was one of the first theoretical arguments that galaxies must have more than you can see in Starlight. In the 1930s, astronomer Fritz Zwicky suggested that most of the mass of the galaxy was “dark.” His ideas were largely ignored until Dr. Ostricar and Dr. Peebles published their papers in 1973.
The response from the scientific community was primarily hostile, Dr. Ostricker said. “I didn't know why,” he said in oral history. “It was just a fact.”
A year later, he and his colleagues, who took in more data from Galaxy Clusters and other star systems, in fact, claimed that most of the universe is invisible.
By the early 1980s, the idea of dark matter had become an accepted part of cosmology, but there were still some conundrums, including calculations that suggested they were older than the universe in which the stars lived.
The missing components, Dr. Ostricar and theoretical physicist Paul Steinhardt, were fudge factors known as cosmic constants at the University of Pennsylvania, proposed in 1995. Einstein came up with this concept in 1917, but later abandoned it, considering it as a disappointment.
As Dr. Steinhardt recalls, he and Dr. Ostrike “were convinced that a universe with only dark, ordinary matter could not explain existing observations.” But when they added the cosmological constants, everything came out right.
They weren't the only ones who had this idea. Cosmologist Michael Turner, who is now retired from the University of Chicago, and Lawrence Kraus, who is now retired from Arizona State, also argued that he supports regaining his position. “To say Jerry was a giant in this field is an understatement,” Dr. Turner wrote in an email, adding, “Sparling with Jerry over science was a privilege and often a learning experience.”
Three years later, two competing teams of astronomers discovered that the expansion of the universe acts as a cosmological constant, accelerated by the “dark energy” that separates the galaxy. The cosmic constant has become part of the standard model of the universe, as predicted by Dr. Ostricar and others.
In another series of papers, he and various collaborators changed the views of astronomers about what is happening in interstellar space.
Princeton's Dr. Ostricker and Dr. Renuu Sen concluded in 1999 that most ordinary atomic matter in the nearby universe is invisible.
Passion that never faded
In Princeton, Dr. Ostricker helped set up the Sloan Digital Sky Survey, an advanced research laboratory in Princeton, the University of Chicago and Princeton, New Jersey.
“Studies will increase our knowledge and understanding of the universe by a hundred times,” he told The New York Times in 1991.
The study, which began in 1998, is now the fifth iteration, generating approximately 10,000 research papers and archived measurements of five billion stars and galaxies, all free to astronomers around the world.
As a Provost, Dr. Ostriker led efforts to significantly expand the university's financial aid program, changing many loans to grants that do not require repayment, making Princeton education more egalitarian. In 2000 he was awarded the Medal of Science by President Bill Clinton.
Dr. Ostricker retired from Princeton in 2012, as his daughter, Eve, joined the astronomy faculty there. He took a part-time job at Columbia University and returned to his childhood neighborhood.
“I grew up in New York City so I couldn't see the stars,” he once told The Times. He found them anyway, and found so much more than we could see if we were in the glare of the streetlights.
It was a passion that never faded. Recently, a reporter met on the sidewalk in front of Columbia, Dr. Ostricker has begun a frenzy of an explanatory novel theory of dark matter.
At the beginning of 2023, he got sick and took him to bed at home. However, he caught up with his research via email and regularly had pizza lunches with his colleagues.
A recent acknowledgement of James Webb's Space Telescope results seemed to reinforce his idea of dark matter, he emailed his colleagues, “Please keep doing a good job.”
The dark universe that he helped to recall half a century ago developed several small cracks, leading to new ideas about the nature of its dark matter.
“It's a very, very, very, very specific and clear theory. So God bless it, it could be wrong,” Dr. Ostriker said in a recent interview. “That's how science goes on. And what we know about it is that it's a bit wrong and not so wrong.”
Dr. Reese, a cosmologist at Cambridge University and the Royal Astronomer, summed up Dr. Ostricker's life in this way. “Some scientists have come up with pioneering ideas on novel subjects.
“He wrote in his earliest papers on the nature of the pulsar, evidence of dark matter, galaxy formation and cosmology. His paper flow continued into the '80s,” Dr. Reese added. “He was enthusiastic about new data and computational techniques. He inspired young colleagues and collaborators not only in Princeton but around the world.”
