Other Worlds
By Felix Winternitz
A star is born
Forgive anyone who suggests that Marco Fatuzzo sometimes keeps his head in the clouds.
The affable physics professor might well agree. After all, his area of expertise is theoretical astrophysics. “In a broad sense,” he says, “it means using physics and applying it to what processes occur in space—how stars live and die, that sort of thing.”
All this birthing and dying takes place in molecular clouds, those regions of space with a lot of gas, so that’s where the physicist spends his time—in a virtual sort of way, via computer models and data spreadsheets. Examining stars that are one-tenth to 100 times the size of the sun, Fatuzzo seeks to sort out some of the interstellar mysteries.
“The puzzle is, no matter where we look in the galaxy, it’s the same,” he says. “The reason it’s a puzzle is that things are very different in varying locations—environment, heat, magnetics.”
In contrast to other aspects of nature, for instance, this becomes baffling. “If you are comparing the environment at the North Pole with the environment in the Sahara Desert, for instance, you would expect differences.”
As part (and particle) of his interest, Fatuzzo focuses his research on the emission of cosmic rays and how they impact star formation. He’s particularly fond of particle acceleration and high-energy radioactive signatures, and enthusiastically launches into a discussion of gamma rays, protons, black holes, pulsars and supernovas at the broach of the subject. All the action, in short, that takes place at the universe’s “Galactic Center.”
“It’s complicated,” he says. “Basically, I take my knowledge of physics, how particles move and collide with other particles, and essentially build computer models. Then you compare predictions with actual signals from these stars, and try to make the picture make sense.”
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Herding bacteria
Imagine that bits of bacteria are actually like herds of cattle. Only tiny. Really, really tiny. Then you can begin to appreciate the challenges that Heidrun Schmitzer faces on a daily basis. The associate professor of physics is charged with corralling these miniscule munchkins while, get this, they are still squirming around inside the human body. No small feat.
Schmitzer—who holds 19 patents in the fields of nonlinear, polarization and quantum optics—now focuses her research on one of the few strains of bacteria in the world that are born with actual magnets inside, specifically, iron oxide nano-particles. Apparently, these magic magnets mutated over eons so they could better orient themselves with the earth’s magnetic field. “It knows, for instance, whether it’s swimming up or down in the water. In this case, they want to be down, in an environment that’s not oxygen rich.”
Schmitzer jumps from the dusty chalkboard in her office where she scribbles formulas and tries to mimic how the bacteria start to rotate, to the nearby physics lab to test her ideas. “It’s interesting to try out, because nobody did this before,” she says. “There are also applications to the findings. There is the idea out there in the medical science field to minimize.”
Whether you’re a physician dealing with cancer drugs, blood cells or body fluids, you end up wanting to pump things through small capillaries or channels. The challenge is how to do that. “You could fabricate tiny metal propellers, but that would be really expensive,” she says with a laugh.
The key to these creatures’ effectiveness, besides a naturally magnetic personality, is their spiral shape. Think a helix, or corkscrew, capable of speeding to 360 rotations per minute. “The test is in how fast you can transport fluid by dragging something in a whirl,” she says, peering into a microscope. A roto-rooter, as it were, on a nano scale.
Other Worlds (continued)
