It is hard to imagine armed guards, metal detectors and bomb-sniffing dogs at the Science Center, but in the wake of last week’s terrorist attacks, security and terrorism experts say nothing can be ruled out.

But they also say the risk of an attack on the nation’s oldest University is a low one, and one that can be lessened still further through basic security precautions.

“Abroad, when people think of things that represent America they do think of Harvard. On the other hand, [Harvard] doesn’t represent America in the same way that the World Trade Center or the Pentagon does,” says Juliette Kayyem, executive director of the Kennedy School’s executive session on domestic preparedness.

“Universities are only a target because of their symbolic nature,” says Michael L. Taylor, president of American International Security Corp. (AISC), a Boston-based security-consulting firm.

Retired Army Gen. John C. Reppert, who now works at the Kennedy School, explains that Harvard’s symbolic stature is both an attraction and a deterrent to terrorists.