One hundred years ago, on Aug. 28, 1911, Victor Hess took to the skies in a hot-air balloon to begin the work that would earn him a Nobel Prize in Physics.

At the time, scientists were puzzled by the fact that the air in electroscopes (instruments used to detect electrical charges) would often become electrically charged no matter how well the containers were insulated. Most physicists believed radioactivity from ground minerals was responsible for this. They suspected that the ionization levels in the atmoshere would diminish greatly at higher altitudes.

Enter a Jesuit scientist. In 1910, Theodor Wulf, S.J., measured ionization at the bottom and top of the Eiffel Tower in Paris. He found that ionization levels were puzzlingly higher at the top of the tower, some 300 meters above ground. But his results were not given unqualified acceptance by the scientific community, nor were the experiments of other scientists who made balloon ascents to record ionization. Their instruments developed defects at high altitudes, casting doubt on their measurements.

Victor Hess, a postdoctoral student at the University of Vienna, was in his late 20s, an accomplished balloonist, a dedicated scientist and an adventurous spirit. He had read about Father Wulf’s experiments and speculated that the main source of radiation could be located in the atmosphere rather than in the Earth.

But before he took to the skies, he did two key things: He determined the height at which ground radiation should stop producing ionization (approximately 500 meters), and he designed his instruments so they would not be damaged by temperature or pressure changes as he went up in his balloon. He then made 10 daring ascents—two in 1911, seven in 1912 and one in 1913—rising to more than 17,000 feet above ground to take his measurements.

What Hess found confirmed Father Wulf’s measurements. The radiation levels increased the higher he climbed. In fact, Hess found that the ionization rate increased approximately fourfold over the rate on the ground. He interpreted these results to mean that radiation enters the atmosphere from outer space.

We now know that cosmic rays are actually high-energy particles that flow into our solar system from far away in the galaxy. But at the time, of course, no one really believed radiation could be coming from a celestial source. Hess had ruled out the sun as the source of the radiation, as he made several of his balloon ascents at night and one during a total eclipse.

“The results of my observation,” he concluded, “are best explained by the assumption that a radiation of a very great penetrating power enters our atmosphere from above.”

This was the discovery that would earn him a 1936 Nobel Prize in Physics. Two years later, Hess arrived at Fordham. In his lab in Freeman Hall, he helped develop a method for detecting minute traces of radium in the body. A company hired him to test its radium-dial workers—women who hand-painted watch dials so that the faces would glow at night. It was probably some of the first environmental testing of its kind in the workplace.

In 1958, Laurence J. McGinley, S.J., president of Fordham, presented Hess with the University’s highest honor, the Fordham University Insignis Medal.

“He has ever been zealous to develop in his students the love of research and the tireless dedication to it which have always marked his life,” the citation reads. “Both as explorer of the secrets God has hidden in nature, and as interpreter of those secrets to his students and to the world, Professor Hess has given a notable example of how the curiosity of the true scientist and the faith of the devout Catholic can dwell harmoniously under one roof.”

—Martin A. Sanzari, Ph.D., Assistant Professor and Director of the Engineering Physics Program, Fordham University

On April 14, Fordham University held a day to honor Hess, its only Nobel Laureate, who received the esteemed international award 75 years ago for his discovery of cosmic particles.

Speaking to an audience of 137 on the Rose Hill campus, Martin Sanzari, Ph.D., assistant professor of physics, called Hess a courageous, dedicated scientist for whom the sky became the limit—literally.

As a post-doctoral student at the University of Vienna, Hess conducted a series of ionization experiments in hot air balloons inspired by the scientist Theodor Wulf, S.J.

In 1910, Father Wulf had measured ionization (electrical charge) levels at the bottom and the top of the 985-foot Eiffel Tower. While most scientists believed ionization was caused by radioactivity from ground minerals, Father Wulf’s experiment showed that ionization levels were puzzlingly higher at the top of the tower than at the bottom.

Father Wulf’s findings were not confirmed scientifically until Hess made a dramatic series of hot air balloon experiments over three years, from 1911 to 1913. On 10 separate trips, Hess went as high as 17,500 feet in a small balloon to measure ionization; what he found was that, at the height of several miles, ionization increased rapidly.

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Hess, right, prior to one of his ten balloon trips to measure atmospheric ionization levels.

Hess concluded that radiation must be entering the atmosphere from outer space, and he named the phenomenon “cosmic radiation,” also called “cosmic rays.”

“At this time, scientists had no idea that this phenomenon possibly existed,” Sanzari said. “This was the discovery that would win him the 1936 Nobel Prize in physics.”

In 1938, Hess, a Catholic married to a Jew, was tipped off by a sympathetic Gestapo officer that he was in danger of Nazi persecution if he stayed in Austria. The Hesses swiftly immigrated to New York, where the Jesuits at Fordham offered Hess a full professorship, Sanzari said.

Hess’ Fordham-based research flourished until his retirement in 1956 and even beyond, said Sanzari. He was tapped to conduct the first tests for radioactive fallout in the United States following the bombing of Hiroshima. At the request of the City of New York, Hess joined a consortium of scientists to investigate the science of producing artificial rain.

He also co-developed a method for detecting minute traces of radium in the human body.

Based on his expertise, Hess was hired by a company to test its radium dial workers—women who hand-painted watch dials so that the faces would glow at night—for radiation levels in their bodies. Hess determined that the workers were being dangerously exposed, Sanzari said.

“This testing was probably some of the first environmental testing of its kind,” he said.

In 1958, the University presented Hess with its highest honor, the prestigious Insignis Medal, which is awarded to “Catholic leaders for extraordinary distinction in the service of God through excellent performance in their professions.” Hess continued to do research at Fordham as professor emeritus until his death in 1964.

In 2008, Hess was feted again by the University when he was made a member of Fordham’s Hall of Honor. A plaque that bears his name hangs in the lobby of Rose Hill’s administration building.

“There are only a few universities in the country who have had a Nobel Prize winner on their faculty,” said Martin Sanzari, Ph.D., assistant professor of physics and the event organizer. “This 75th anniversary is a great opportunity for us to celebrate it.”

To pay homage to Hess’ research, Mark Alford, Ph.D., professor of physics at Washington University, delivered a keynote lecture on the area of Hess’ expertise: cosmology and particle physics.

“We scientists all hope that we, too, might make a difference of Hess’ level in the world,” Alford said.

Hess ended up at Fordham University, where he taught in the Department of Physics until he retired 1956.

This week, the University honors Hess’ legacy with two special lectures on Thursday, April 14 on the Rose Hill campus. “Victor Hess Day” coincides with the 100th anniversary of his discovery of cosmic rays and the 75th anniversary of his Nobel award.

“There are only a few universities in the country who have had a Nobel Prize winner on their faculty,” said Martin Sanzari, Ph.D., assistant professor of physics and the event organizer. “This anniversary presents a great opportunity for us to celebrate it.”

Mark Alford, Ph.D., professor of physics at Washington University, will deliver a keynote lecture on the area of Hess’ expertise: cosmology and particle physics. Sanzari will speak on Hess’ scientific achievements and give some detailed accounts of the research that Hess did while a member of the Fordham faculty.

The event begins at 3:30 p.m. in Freeman Hall, Room 105. Sanzari will speak 3:50 p.m., followed at 4:10 p.m. by Alford. For further information contact Sanzari.

A native of Austria, Hess earned a Ph.D. in physics from the University of Vienna in 1906  and later worked at the Physical Institute in Vienna, where he first began his seminal research in the field of radioactivity.

By conducting atmospheric readings while making several ascents in a hot-air balloon, Hess discovered cosmic rays—high-energy radiation originating in outer space. This breakthrough opened the door to many new discoveries in nuclear physics and earned Hess the 1936 Nobel Prize in Physics.

In 1958, the University presented Hess with its highest honor, the prestigious Insignis Medal, which is awarded to “Catholic leaders for extraordinary distinction in the service of God through excellent performance in their professions.”

“Much of the university community is not aware that Fordham had a Nobel Prize winner,” said Sanzari. “We would like to share that fact, and we hope that a cross-section of faculty, students and administrators from all departments will join us to hear Hess’ story and his science.”