When we gaze at the night
sky, we see sparkles of visible light. But stars and galaxies also unleash
radio waves, x-rays, and other radiation toward earth. Ignoring that steady
rain would be like hearing just one octave within nature's symphony of sounds.
Astronomers capture those special waves with some rather odd telescopes,
including one in New Mexico called Milagro. It's a football-field-sized
reservoir, shielded by a light-tight cover and chock full of water and
detectors. This device catches gamma rays, the most powerful bursts of energy
in the cosmos.
It's fitting that Miguel Morales, a physics graduate student at UCSC, works on Milagro. Morales has always loved "wonder science," the big questions about the universe that Carl Sagan used to pose.
"Many areas of physics are pretty well mined," Morales said. "But with Milagro, we're at such high energies that we don't know what we might find. That's an interesting place to be."
Morales earned his B.S. at Swarthmore College and then taught science for three years at a private high school in Milwaukee. One of his course themes was, "What is matter made of?" Today, he asks a very different question: "What are some of the wildest things matter can do?"
Gamma rays give Morales some clues. They crash into earth's atmosphere, triggering showers of other particles that cascade to the ground. In Milagro's dark waters, the particles spark tiny flashes that Morales and his coworkers can detect with sensitive light tubes (pictured). By analyzing the flashes, the team tries to trace where the gamma rays came from--the remains of a supernova, for instance, or a black hole gulping a stellar neighbor.
Milagro intercepts less interesting cosmic particles as well, thousands
of them every second. These also spawn flashes, but they differ in subtle
ways. Morales is working on smart computer software that zeroes
in on genuine gamma rays. He models his approach on a biological network
of simple neurons, almost like the brain of an insect. Over time, the network
should "learn" to spot all gamma-ray flashes in their many guises.
"I'm trying to design something that behaves like the early visual processing system of an animal," Morales said. "It boils down to recognizing objects. That's the first question any developing brain has to deal with."
The project reflects the creativity fostered at the Santa Cruz Institute for Particle Physics (SCIPP), a research unit at UCSC. "I would not thrive in a graduate student factory," Morales said. "At SCIPP, the professors listen to our ideas, even the crazy ones. It makes learning much more entertaining."
--Robert Irion