Childhood & Early Life
Martin Lewis Perl was born on June 24, 1927 in New York City, New York to Fay and Oscar Perl. His parents were Jewish who had immigrated to the USA from Polish-occupied Russia. His mother worked as a secretary and bookkeeper for a textile firm while his father worked as a stationery salesman before founding his own printing and advertising company.
Academically, Perl was a bright student. Upon completing his early education, he enrolled at James Madison High School in 1942. Despite being a good student and winning a physics prize, Perl did not aim to become a scientist as he wasn’t sure if he could make a living out of the profession. As such, he chose chemical engineering over physics research.
Following high school, he enrolled at the Polytechnic Institute of Brooklyn for a course in chemical engineering. However, with the onset of World War II, he left his studies to take up a course in the United States Merchant Marine Academy. For a year, he was drafted into the army. Post war, he resumed his studies and graduated from the institute in 1948.
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Following his graduation, Perl took up work as a chemical engineer for the General Electric Company, producing electron vacuum tubes. His interest in the working of television tubes led him to enrol for a course in atomic physics and advanced calculus at Union College, Schenectady, New York.
Perl’s course in physics ignited his interest in the subject so much so that he decided to study the subject formally. He graduated as a physics student in 1950. Following this, Perl enrolled at the Columbia University for a PhD. Under the guidance of Isidor Isaac Rabi, he completed his thesis on measurements of the nuclear quadrupole moment of sodium, using the atomic beam resonance method. He received his PhD in 1955.
Post PhD, he worked at the University of Michigan for eight years. He studied the scattering of pions and later neutrons on protons using bubble chambers and spark chambers. Though he worked on the physics of strong interactions, he sought for a simpler interaction mechanism to study. He gave electron and muon interactions a steady consideration.
In 1963, he moved to Stanford Linear Accelerator Center (SLAC), California. At Stanford, Perl was keen on satiating his curiosity in the understanding of muon. He wondered why muon interacted exactly like the electron despite being 206.8 times heavier and why it decayed through the route that it does.
His quest for the understanding of muon led him to a series of experiments. He wanted to know why there was a single muon and that was there a possibility that more muons’ existed?
Together with his group, he aimed at finding an even heavier electron than muon that would help explain the role of muon in the grand scheme of things. For this, he realized that such particles could be figured out only through the new collider, Stanford Positron Accelerating Ring. The method would lead to the decay of particles radioactively, leaving behind a distinctive trail of subatomic debris.
In 1973, Perl began the magnum opus of his career. The Spear machine became operational, colliding electrons and positrons in higher energy to produce tiny fireballs. Though the collision led to the production of a particle, the life of the unknown particle was just 2.9×10−13 second long, leading to its decay within a few millimetres of the collision.
By 1975, it was clear that there existed something that was heavier in mass than an electron. Perl excited by the new research, held a conference and made public his finding of a new particle.
Perl’s discovery of the new particle met with a lot of criticism early on. He was severely panned as there was no logical explanation of his finding. It took Perl and his group more than two years to collect data and establish the existence of ‘tau’, the elementary particle similar to electron. Together with electron and muon, it formed a triad.
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‘Tau’, meaning ‘third’ in Greek was 3500 times as massive as electron. Despite its massive size, it lived for only third of the trillionth of a second before decaying into a spray of its lighter brethren, nuetrinos. Tau is the heaviest of the electron brothers. As per the rules laid down in the physical world, matter in the universe is divided into two sets of six particles each – six leptons comprising of three electron brothers and three nuetrinos and six quarks which make up for innards of particles protons and nuetrons.
Perl did not give up on his research career after his outstanding discovery of the tau lepton. He continued to investigate the nature of quarks. Post retirement as well, Perl continued his research, collaborating with scientists at SLAC on numerous projects including one investigating dark energy.
Apart from his research, Perl took up academic positions as well. From 1955 to 1963 he served as an instructor and later associate professor at the University of Michigan. In 1963, he joined the faculty of Stanford University, and became Professor Emeritus in 2004. He even joined University of Liverpool as a visiting professor.
Awards & Achievements
In 1995, Perl was felicitated with the Nobel Prize in Physics for his discovery of tau lepton. The discovery established the fact that there was an additional family of particles alongside two previously known families. He shared the prize with physicist Frederick Reines, who discovered another subatomic particle, the neutrino, in the 1950s.
He served on the board of advisors of Scientists and Engineers for America, an organization focused on promoting sound science in American government.
In 2009, Perl received an honorary doctorate from the University of Belgrade.