By John Yemma

A Brandeis Lab helps scientists study the effects of zero gravity on humans and their machines.

Rub your stomach while you pat your head. Spin around a few times. Most parlor tricks are designed to show the limitations of motor control and how your senses can deceive you.

Now imagine trying those tricks in zero gravity. James Lackner has done just that. He has ridden through more than 15,000 parabolic maneuvers aboard the National Aeronautics and Space Administration's famed "vomit comet," the KC-135 aircraft used to create weightless conditions for up to 30 seconds for astronauts in training. He has spun, done deep knee bends, turned somersaults. It is part of his work as director of the Graybiel Spatial Orientation Laboratory, at Brandeis University.

Lackner has learned that, far from our being masters of the universe, ready to boldly go where no one has ever gone, we humans are very much slaves of Earth's gravity. We can adapt to environments other than 1-G, but it's no picnic.

Weightlessness looks like a blast on TV and in the movies. For astronauts, however, it quickly becomes as hassle. If not for Velcro, foil-packed dinners, and special toilets, the space shuttle would be an even dirtier, more dangerous habitat than it already is. Even the neatest astronaut inadvertently contributes crud to cabin air, where it stays suspended, affecting eyes, lungs and delicate interments. Zero-G causes other problems as well, including calcium loss from bones, atrophy of muscles, and visual disorientation. Cooking food, taking a shower, dealing with even minor first-aid - all are problematic without gravity. "Can you imagine a routine problem like an appendectomy in a weightless environment?" asks Lackner. "What a mess that would be."

Gravity is our most basic human assumption. The force of gravity is part of every terrestrial activity, it is a given from the time we first drop into the world. It takes three or four years to become masters of 1-G; those who are better at it than others end up in the Olympics or the NBA. But all humans need their feet on the ground for reasons of health, safety, and convenience. Even small annoyances are compounded in Zero-G. Losing the keys to your spacecraft, for instance, would force you to look not just on tables, sofa cushions, or the floor. You would have to search the space above you, too.

For many years, scientists have planned on generating centrifugal force as replacement for Earth's gravity on long space flights. Remember the carnival ride on which everyone spins in a circular chamber and the floor drops out? The wall you are pinned against on the ride would be the floor of a spacecraft using artificial gravity. If astronauts don't want to float along in Velcro-lined pig pen, turning into space slugs, they are destined to spin through space.

Lackner and his colleague, Paul DiZio, study the centrifugal-force environment in their Brandeis lab, which features, among other clever devices, one of the world's only rotating rooms. The room is about the size of a tight two-car garage. It is anchored to terra firma in the basement of the Rabb Graduate Center, so it's not a perfect replica of a rotating spacecraft. It is, however, useful for understanding how unusual forces play on mind and body.

The room can rotate at up to 40 r.p.m., producing a force equal to six times that of gravity. A graduate student works the controls, and you put your back to the wall, just like in the vertiginous carnival ride. On a recent Friday, DiZio and I took a 10 r.p.m. trip - not enough to make a reporter loose his lunch, but enough to get the idea. DiZio tells me to point straight ahead. My arm swings out to the side. I toss a tennis ball across the room, and it flies wildly to the right. This is a product of Coriolis force, a side effect of rotation, and it takes practice for my motor control to adapt. I turn my head to catch what DiZio is saying, and a wave of dizziness comes over me.

Other experiments at Graybiel are thrill rides for only the most daring student volunteer. Most, however, are tame tests of how the senses, nerves, inner ear, and brain read - and often misread - information. Lackner and DiZio have worked on problems with eye-hand coordination, visual tracking, auditory response, and other normal human functions. If you walk forward in a rotating room, you get heavier; walk backward, and you get lighter.

None of these problems are insurmountable. Some might even be beneficial. But it is clear that artificial gravity is no walk in the park. "We think that people can adapt pretty well for simple tasks," says Lackner. "Humans function in the gravitational-force environment of Earth without ever thinking about it. We don't perceive the actual forces on our bodies. When we move about, we feel virtually weightless. So in a new environment, you find that you do make errors if you haven't adapted."

We may be children of the universe, but our design parameters and our habits work best in one particular spot of that universe, our gravitational home. As Lackner puts it: "We've grown up in 1-G. We take it for granted."

And when we leave home, we're going to miss the little things.

The Boston Globe Magazine
June 16, 1996, Page 11