The universe is made of fundamental particles that cannot be divided. Despite there being more atoms in a grain of sand than there are stars in the universe, atoms are not the smallest building blocks of the universe. They are in fact composed of smaller, subatomic particles. Particle physics is the scientific field devoted to understanding subatomic particles; its Standard Model theorizes which subatomic particles exist and which rules determine their behavior.
Despite focusing on tiny subatomic particles, particle physics helps us understand the vastness of space. And it will almost certainly continue to help us learn more about the cosmos. The field, for instance, may help us decipher the composition of dark matter, which cannot be seen but which apparently provides extra mass that allows galaxies to maintain their shapes. Another way particle physics may adjust our understanding of the universe is by supporting or falsifying theories about the existence of other dimensions.
Particle physicists seek to expand the Standard Model. They often work at colliders, which are giant machines that smash streams of particles into one another. The largest collider in the world is the Large Hadron Collider (LHC), a 27-kilometer ring-shaped tunnel beneath the France-Switzerland border. The LHC is one of several colliders managed by the European Organization for Nuclear Research (CERN), a research organization with 22 member states.
Filling Space spoke with Dr. Seyda Ipek, a postdoctoral particle physics researcher at University of California, Irvine. She shared her thoughts on the field and her experience in it.
What are particle colliders and what is the most exciting experimentation being done with them right now?
Particle colliders are experiments where beams of particles are accelerated to high speeds (close to the speed of light) and smashed onto another beam of particles or onto a different target. The particles that are accelerated can be elementary particles like electrons or positrons, or larger particles like protons and antiprotons. Currently the world’s largest particle collider is the Large Hadron Collider at CERN. It collides two beams of protons. After the collisions, we can sift through the end products to see if any new particles, beyond the ones we have in the Standard Model of elementary particles, are produced.
Can you explain how advances in your field affect everyday people?
This is hard to quantify; particle physics is not like medicine in regards to our everyday lives. We aspire to further our understanding of the building blocks of our universe. This contributes immensely to human knowledge, even when it might seem impractical. It also sometimes takes decades for us to understand if something is “useful”. For example, when electricity was first discovered, it was used for party tricks. It took about a century for people to recognize its true value.
One very interesting gift of particle physics to humankind is the World Wide Web. It was invented at CERN in order to share the large amounts of data effectively with faraway researchers. This is not directly related to particle physics, but shows that we don’t always know what the advances are going to be when we embark on some academic research.
How did you come to be interested in particle physics, and what would you suggest to individuals who wish to enter the field?
I was interested in physics and mathematics since high school. In college, I majored in physics but took many classes from the math department. I didn’t really know much about particle physics back then, but that was part of the allure: I wanted to learn something I had no idea about. I knew this was my calling after taking a Quantum Field Theory class; it was a perfect combination of mathematical tools and physics. Unfortunately, many students think they want to study particle physics until they take QFT. So, if you want to be a particle physicist, be prepared for pages of calculations of cross sections and make sure you have the attention to catch the correct factors of pi.