ean Gary B. Schuster of the College of Sciences points to development of the quantum theory as among the most significant achievements of the century. • “It changed the way we view the physical universe from one of an infinite continuum to a universe of discrete states,” he says. • Physicist Max Planck’s work provided a new foundation in physics and mathematics that ultimately was responsible for the “invention of the transistor, our understanding of spectroscopy, and led to creation of most of the things we think of as technological breakthroughs of the 20th century,” he explains. “Without that fundamental understanding, none of those technological developments would have occurred.”

r. Sue V. Rosser, dean of the Ivan Allen College, says the tremendous social gains that followed contraceptive and reproductive technologies rate as important achievements of the past century for both men and women in the United States.

“These technologies have permitted women to limit the number of children they have and decide when they want to have them,” she explains. The effect has been to free women from traditional roles to enter the work force in huge numbers. “It has also freed men, in that the responsibility for breadwinning is shared. Also, with smaller families, men don’t feel as constrained with just having to earn money to provide for their families.”

Looking ahead, the 20th century may one day be best remembered for the development of bioengineering, which owes some of its roots to the contraceptive and reproductive research of the 1950s, Rosser says.

“Along with its traditional engineering disciplines, Georgia Tech is moving into biomedical engineering and other kinds of biotechnologies,” she says. “The idea of engineering life—gene splicing and sequencing DNA and so forth—represents a fusion of the mechanical with the biological. Many people see this new type of engineering as the technology of the 21st century.”

rom an architectural point of view, Dean Thomas D. Galloway of the College of Architecture points out several key 20th century innovations: computers, which as design tools allow greater productivity and the ability to handle large-scale projects that would be virtually impossible under the manual system, and development of the glass-curtain wall, an innovation that has “facilitated the modern movement in architecture and significantly changed the skylines of American cities.”

On a larger scale, Galloway notes that the automobile, though technically a 19th century invention, didn’t come into its own until the 20th. With it came fundamental changes in the built environment, including the rise of suburbia and the decentralization of the population, highway construction and diminished air quality.

Air conditioning had a tremendous effect not only on buildings, but on regional development patterns in the United States, according to Galloway. “The growth of the Sunbelt could not have happened at the speed and magnitude it did without air-conditioning systems,” he says.

mong those developments is the stored-program computer, which Dr. Peter A. Freeman rates as one of the great technological advances of the century. The device, the first practical models of which appeared in the 1940s, was the direct ancestor of the modern computer, explains the dean of the College of Computing. The distinction between it and its computing-type predecessors is that the operating program resides within the computer and can be modified by the device itself.

“That’s the key operational difference,” Freeman explains. “It allows a computer to do the things it does. Without the computer being able to modify its own program, and without having that program explicitly stored in the computer so you can replace it with another, you would not have the modern computer.”

He adds that the miniaturization of electronics is a related noteworthy advance, though it’s more a process than a single invention.

“Miniaturization is a way of implementing technology,” he says. “It has made electronics useful in a wider variety of situations. In theory, without miniaturization you could still have all the computers we have today. But you couldn’t have them sitting on every desktop.”

ew, transformational technologies related to health and communication—the transistor and silicon chip in particular—have been hallmarks of the past century, and set the stage for the Information Age and the emerging Biotechnology Age, according to Dean Terry C. Blum of the DuPree College of Management. “These technologies include recombinant DNA—and the implications it has for technology transfer from universities because of the combination of social policy through the Bayh-Dole Bill—penicillin, polio vaccine, oral contraceptives, insulin and Prozac, along with the heart-lung machine: a personal choice since my daughter is alive because of this invention.” She also adds public-health measures contributing to clean air and water to the list.

or their work describing the structure of DNA, Schuster includes James Watson and Francis Crick among the founders of the biological revolution. Like his colleagues, he believes genetic engineering may in retrospect prove to be a momentous legacy of the 20th century. “Life evolved on this planet, according to a particular scheme, for two-and-a-half billion years, and in the past 25 years we’ve changed that scheme,” he says. “This is going to have profound implications. We have no idea where it’s going or what it’s going to lead to.”