Spring 2010 Issue
This physics professor’s ‘lab’ is light years away
By Illyce Suarez
Some people are out there, and others are way out there. Barry’s new assistant physics professor, Dr. Maurizio Giannotti, can be described as falling into the latter category – at least when it comes to his research. He studies a natural phenomenon called a supernova - essentially what happens when a huge star explodes - and uses it as a “laboratory” to explore an eternal question: What is the universe made of?
To begin with, it’s made of electrons, protons and neutrons, the major building blocks of everything we see and feel, but it is likely that there are many other particles hiding “beneath the woodwork.” Specifically, Giannotti is searching for a hypothetical particle called the axion that is likely produced in supernovae. The axion is hypothetical because no one has ever detected it.
So why search for particles that may not exist? The reality is that if we take into account all the particles and forces we are sure about - what is known as the standard model of particle physics - we still can’t fully explain how the world works. For example, why doesn’t anti-matter cancel out all matter, including the earth? Are there extra dimensions beyond space and time curled up and hidden from view? And what exactly is dark matter?
To fill these gaps in knowledge, physicists sometimes propose new particles. The axion in particular plays a starring role in what physicists call the Strong CP problem. Simply put, there is a hole in the theory that explains the Strong force (the glue that holds atomic nuclei together) so that predictions don’t always match what happens in the real world. “The axion was named after an old detergent,” explains Giannotti, “because it washes away the Strong CP problem.” Now the race is on to actually find it.
Giannotti is not alone as he embarks on this great race. The Italian native moved to Miami last July with his wife, Elizabeth Price, who will soon begin teaching Developmental English at Barry. He also has two dedicated students on his team, Rafaela Nita and Erin Welch. Nita, a senior, who is planning to pursue a doctorate in chemistry, became interested in his work during a presentation he gave at Barry while he was interviewing for his current position. “She asked a lot of intelligent questions during that talk, and we stayed in touch,” Giannotti says.
Nita and Welch are collaborating with Giannotti on the axion project for their independent study research class. The class is focused on studying relativity, quantum mechanics, and astrophysics, as well as engaging in thought-provoking conversations. “Dr. Giannotti is a very open person and a good listener,” Nita says. “We get together two or three times a week to talk about the research and discuss interesting papers we’ve read.”
These conversations are helping his students build critical thinking skills, but for Giannotti, they are more than just teaching opportunities. He sees them as a vital part of his research: “Talking to students opens my mind. They help me to see the big picture and look at things in a different way, and that can bring new ideas.”
His engaging manner seems to be working well in the classroom too. On a recent stroll through the halls of the Department of Physical Sciences, a student from his introductory physics class was overheard saying, “Physics is fun.”
Part of the “fun” of searching for axions is that they are invisible. They interact so weakly with standard matter that they can travel through walls or anything else placed in their way, including particle detectors, making it difficult to perform an experiment in a normal laboratory. Instead, Giannotti looks to the skies. “It’s a charming idea because astrophysics deals with huge stars. What do they have to do with tiny particles like axions? Actually, there is a big connection,” he says.
The inside of a supernova can be thought of as a laboratory where a medley of ingredients mix and mingle in the perfect environment for making axions. These axions are believed to be released with the explosion. “If a supernova is close enough, but hopefully not too close, we can study it,” Giannotti says. His research centers around two such events: Supernova 1987A, recorded in 1987, and Cassiopeia A, first seen more than 300 years ago. Although any axions released in these supernovae cannot be observed directly, Giannotti hopes that an interesting property will remove their cloak of invisibility. With time, axions decay into gamma rays, a form of light that is very easy for space telescopes to see.
By making hypotheses about the properties of axions, Giannotti is able to calculate the spectrum of light they would emit as they decay. A large area telescope such as NASA’s FERMI Gamma-Ray Space Telescope is capable of detecting this light. If the data matches his calculations, he will have found the elusive axion, but even a negative result yields valuable information by helping to narrow the search.
Combining astrophysics with particle physics is a relatively novel approach, one that Giannotti became interested in during his three-year postdoctoral fellowship at the Los Alamos National Laboratories in New Mexico. The site of top-secret national security research and birthplace of the Manhattan Project is a world-renowned institution where cooperation across disciplines is the norm. As his former Los Alamos colleague, Dr. Leanne Duffy, puts it, “Los Alamos offers the opportunity to speak with people from many different backgrounds at seminars, meetings, or even in the hallway.”
The same open manner and attention to detail that Giannotti brings to his classes at Barry were great assets to his teams at Los Alamos. “He is always very thorough and brings good ideas to the table,” Duffy says. Another former Los Alamos colleague, Dr. Alex Friedland, agrees and adds, “He has good taste in choosing problems.”
And as long as the axion remains a mystery, Giannotti says he’ll keep going back to his lab in the sky.