In the film, which is a part of the NOVA series Secrets of Lost Empires, a team of timber framers and other specialists design, build, and fire a pair of trebuchets, a devastating engine of war popular in the Middle Ages.

The film, which is a part of the NOVA series Secrets of Lost Empires, documents a 1999 effort by a NOVA-assembled crew of scholars and timber framers to design and build a Chinese bridge known only from an ancient painting.

In "Tattooed Doctor," the first hour of NOVA's "Survivor M.D." series, emergency-room physician Dr. Tom Tarter eloquently describes some of the challenges and rewards of emergency medicine.

In 1987 NOVA embarked with seven brilliant, natural-born survivors on the longest-running boot camp in higher education: the nearly decade-long process of training to be a fully qualified doctor. Now all but one of them (who switched careers) are out in the world in high-powered medical careers, trying to balance the demands of work, families, and personal lives, as NOVA reports on Survivor MD, which airs in three one-hour segments.

In 1987 NOVA embarked with seven brilliant, natural-born survivors on the longest-running boot camp in higher education: the nearly decade-long process of training to be a fully qualified doctor. Now all but one of them (who switched careers) are out in the world in high-powered medical careers, trying to balance the demands of work, families, and personal lives, as NOVA reports on Survivor MD, which airs in three one-hour segments.

In 1987, NOVA's cameras began rolling to chronicle the lives of seven young, bright medical students embarking on the longest and most rigorous endeavor in higher education: the years-long journey to become a doctor. From their first days at Harvard Medical School to the present day, none of them could have predicted what it would take, personally and professionally. In "Doctors' Diaries," a two-hour special, NOVA returns to find out what sorts of doctors—and people—the seven young students have become. The program is the latest installment in the longest-running U.S. documentary of its kind.

In 1987, NOVA's cameras began rolling to chronicle the lives of seven young, bright medical students embarking on the longest and most rigorous endeavor in higher education: the years-long journey to become a doctor. From their first days at Harvard Medical School to the present day, none of them could have predicted what it would take, personally and professionally. In "Doctors' Diaries," a two-hour special, NOVA returns to find out what sorts of doctors—and people—the seven young students have become. The program is the latest installment in the longest-running U.S. documentary of its kind.