A half-meter-long protein floats in midair, several centimeters in front of a monitor. It looks like an oversize curled ribbon from a birthday package. As three molecular biologists maneuver around the image, studying the complex molecule from different angles, it begins to fold, slowly twisting and interlocking into a tangled knot. Its shape is a clue to the function it performs in the human body: some proteins produce chemical reactions or behave like a kind of scaffolding for cells, while others help with cell division. Creation of a drug that encourages or blocks a protein's action-say, preventing cancerous cells from dividing-could lead to more effective treatments. One of the researchers uses a stylus to prod the protein at several points. As she does so, the protein refolds itself, revealing a location that could be targeted with a drug to inhibit the protein's function.

This kind of interactive science is on the way, and it will be made possible by a new generation of 3-D video displays. The technology enlists the power of holograms-or reasonable facsimiles thereof-to dish up startlingly realistic images that appear to pop out of the screen. Imagine the 3-D scenes produced by the venerable View-Master toy cranked up to "11" on the reality dial. But the new 3-D video images won't require  special viewing devices. Users won't have to don the headgear or eyewear that tends to be distracting and can cause eyestrain, as they do with current so-called 3-D displays.

No. Three-dimensional holographic video images will be generated by a computer rather than being fixed in a static medium; they will be shown in full-motion color and, with input from a user, changed on the fly. What's more, viewers who move around a holographic video image will be able to see it moving from every side-a phenomenon important to realism and one that many conventional eyeglass-based systems cannot replicate.

The mainstream of doctors, scientists, researchers, and new-product developers who already rely on high-end computer displays to visualize their work will see dramatic differences in this new technology. Currently their work is constrained by the flat, two-dimensional images of conventional displays. No matter how cleverly the screens are dressed up, they can't convey all the nuances, intricacies, and immediacy of real objects in the 3-D world. Because the new video holograms produce fully 3-D images that float in space near the viewing screen, they can be examined from different angles by multiple viewers. Geophysicists examining high-resolution images of rock formations will be able to predict the location of hidden oil deposits with greater accuracy. Industrial designers will be able to modify a sports car's body using the tip of a stylus, instantly establishing the change's effect on overall design. Military commanders will be able to visualize the best battlefield scenario. Surgeons will be better able to determine the safest approach for removing a brain tumor without ever wielding a knife. "Someday we're going to wonder how we used to put up with 2-D images," says Stephen Benton, who heads the Spatial Imaging Group at the MIT Media Lab.