Martin Schmidt, the Dutch-born American astronomer whose discovery of quasars changed our understanding of the evolution of the universe and revealed the power and effectiveness of monsters roaming deep space, died in his Fresno home.
Schmidt, professor emeritus at Caltech, died Saturday at the age of 92.
Schmidt only recently arrived at Caltech when he climbed into the observation cage of the Mount Palomar Great Telescope to try to understand measurements that radio astronomers got from a strange object that was supposed to be a star but couldn’t be.
The object, known as 3C273 in the flavorless astronomy argument, was 3 billion light-years away, a large part of the way back to the Big Bang. However, it was hundreds of times brighter than our galaxy of 100 billion stars. Even more intriguingly, when Schmidt finally got his signature light spectrum, it looked like nothing he had seen before.
After weeks of futile bewilderment, Schmidt told his wife, Cory, “Something terrible happened in the office.”
It turns out not so terrible, after all. Martin Schmidt discovered the quasar (a quasi-stellar radio source), an engine of incredible power. It’s unbelievable, it was another six years before Donald Linden Bell, one of Schmidt’s students, came up with an explanation: a hungry black hole consuming a meal. Nothing can escape the frightening gravitational force of a black hole, but the material at the edge of the ripple vortex is so hot that bursts of energy shoot out at nearly the speed of light.
This burst of energy was what radio telescopes on Earth were capturing. It wasn’t a galaxy, and it wasn’t a star, or even a black hole, exactly. It was the radiation that resulted from the greatest show in the universe.
This discovery made Schmidt famous. His angular, bespectacled face appeared on the cover of Time magazine. Trophies flowed his way. And unlike some discoveries of anomalies in space, Schmidt’s work has grown in importance over time, as cosmologists realize the role quasars play in building the modern universe.
“The discovery of quasars is one of the fundamental discoveries of astrophysics, and it has completely changed astronomy,” said George Djorowski, professor of astronomy and director of the Center for Data-Driven Discovery at Caltech. Black holes have been a theoretical concept for some time, but quasars have proven their existence in a concrete way. They will play a role in everything from proving the existence of dark matter to the formation of galaxies.
In 2008, more than four decades after its discovery, Schmidt and Linden Bell received the $1 million Kavli Prize for Astrophysics for their work that “dramatically expanded the scope of the visible universe and led to our current view of a violent universe in which massive black holes play a major role.”
Schmidt, the son of a government accountant, was born in Groninge, Netherlands on December 28, 1929. At the age of twelve, he built his first telescope using a lens he had found on his grandfather’s farm. He was still a student at the University of Groningen when he caught the attention of the country’s leading astronomer, Jan Oort, who gave his name to the Oort cloud of comets surrounding the Solar System.
He put Ort-Schmidt to work at the University of Leiden Observatory, the oldest in the world, to measure the brightness of comets. But it was his other early work, studying the spectral signature of hydrogen, which would prove important a decade later, when he discovered something that made the supernova look like a baby gun.
Schmidt’s reputation for persistence eventually caught the attention of astronomers at the Mount Wilson Observatory and Palomar in Southern California. At the time, those observatories boasted the world’s largest gathering of star surveyors, from Walter Bade, who doubled the known size of the universe, to Fritz Zwicky, who predicted the existence of dark matter.
By the time Schmidt joined them in 1959, an important instrument was revolutionizing astronomy, the radio telescope. For thousands of years, visible light was the only medium that people used to make sense of what was going on outside Earth. But electromagnetic waves come in all sizes, from the shortest wavelengths, the highest frequencies – strong gamma rays and X-rays – through ultraviolet, visible, infrared, microwave and finally low-frequency radio waves.
Radio waves are much longer than light waves, ranging from centimeters to kilometers, which is why radio telescopes must be so large. This may be a problem, but a radio telescope has major advantages, including the ability to see through interstellar dust that blocks radiation at shorter wavelengths. This means that radio telescopes can reach very distant regions of the universe.
By 1961, Schmidt finally got his chance to operate the large 200-inch telescope at Palomar, an instrument so large that even the greatest astronomers waited months and years for a chance to use it. Schmidt’s mission was to track down some of the strange objects detected by radio telescopes. It was hard and time-consuming work, but one for which the sick young astronomer was a perfect fit.
“It was romantic!” Tell an interviewer later. “Once in a while you just have to stop and look around.”
Most of the radio sources turned out to be ordinary elliptical galaxies. But a few of them were baffling. They did not look at everything like galaxies. Instead, they looked very much like stars. Very powerful stars. He was particularly interested in 3C273, which radio astronomers in Australia had narrowed down enough to a region of the sky that Schmidt thought he had a chance of picking up at Palomar. In late December 1962, just weeks after the Cuban missile crisis pushed the world to the brink of nuclear annihilation, Schmidt finally solved the problem. But this did not solve the mystery. In fact, it was just the beginning.
The mysterious 3C273 turns out to be two sources, a star and a jet of attached gaseous matter. The spectra he got on his photographic plates are meaningless. The emission lines on the spectrogram didn’t match up with anything he knew.
A few weeks later, Schmidt was sitting in his office on the second floor of the Robinson Building at Caltech, when something clicked. I suddenly realize that the image looks a lot like a fingerprint of hydrogen, the primary fuel for stars. Only it was massively redshifted, which meant that the object was moving away from Earth at an astonishing speed, about 30,000 miles per second, and was fantastically far away.
However, it was much brighter than most of the closer galaxies. If it is so far away, how can it be seen? It shone with the light of 2 trillion stars, but it was only the size of our solar system, less than a light year away, while the Milky Way is 100,000 light years in diameter. what was going on?
Schmidt was still not sure if he was looking at something much closer, in our galaxy, and therefore less interesting, when he went to a colleague baffling about a similar object. It had the same signature, and was more redshifted, which means it was farther away. That was the aha moment.
In March 1964, Schmidt became an instant scientific celebrity when he and his colleagues published four classic papers describing what Schmidt called quasi-stellar radio sources. It took some time before the scientific community accepted the term quasars.
In an interview in 2014, Schmidt recalled excitement about his discovery. It was all very interesting, not meaningless, good for his career. He became chair of the Department of Physics, Mathematics, and Astronomy at Caltech in 1975, then director of the Hill Observatories, which operate the Palomar and Mount Wilson instruments.
“It was an amazing event,” Schmidt said. “But once it’s done, it’s done.”
The most satisfying work came later, when he was able to show where quasars lie in the universe’s timeline. As one of the most remote things to study, which also makes it the oldest, “it shows a snapshot of what the universe was like at the time,” he said. “I was able to gather evidence about the early evolution of the universe.”
According to Djegorovsky, they provided the first indications of what is known as the era of reionization of the early universe, when stars and galaxies first began to form. “This was one of the main steps in the evolution of the universe,” Djegorovsky added.
Quasars turned into cosmic dinosaurs, as ancient beasts roamed the landscapes of space and fed on weaker creatures to satiate their colossal appetites. This, along with the discovery of the cosmic microwave background, proved to be the final nail in the coffin of the so-called steady-state theory of the universe, which asserted that the universe has always been this way, and always will be.
The remnants of the ancient universe, fantastically remote and completely different from anything being created in space today, were evidence that the young universe was a completely different place.
It is now believed that there are supermassive black holes at the center of most large galaxies, such as the Milky Way. But relatively few, these days, have quasars, or what are now called active galactic nuclei. They are active because they eat. Over time, the vast majority of black holes consume all the dust, gas, and other things in their area and go into hibernation.
The black hole at the center of the Milky Way, known as Sagittarius A*, is one of those. However, in the future, his appetite will wake up. The nearest large galaxy, Andromeda, is steadily approaching the outskirts of the Milky Way. The two giants will collide in about 4 billion years.
This event will trigger tidal waves of gas and dust on the deadly shore of black holes in both galaxies. It must be a great show, but no one on earth will see it. By that time, the Sun will have swollen and reddened and made our planet uninhabitable.
After his success to fame, Schmidt served for two years as president of the prestigious American Astronomical Society. Along with the Kavli Prize, he was awarded the Royal Astronomical Society’s Gold Medal in 1980 and the James Craig Watson Medal in 1991.
Schmidt was married to Cornelia “Corey” Tom Schmidt for 64 years, until her death in 2020. He is survived by his three daughters, Ann, Marijke, and Elizabeth.
Johnson is a former staff writer for The Times.