Science’s Hall of Fame : To walk through Caltech is to revisit Einstein, Oppenheimer, Millikan and other 20th-Century lions of the field.

Caltech. The very name conjures headlines of seismology and Richter scales, of outer space and underwater exploration, of Einstein, Oppenheimer, Pauling and other marquee names in physics and chemistry.

As one of the world’s premier research schools of science and engineering, the 103-year-old California Institute of Technology is a mouse that roars--only 900 undergraduates and 1,100 graduate students with dreams that reach not just for stars but whole galaxies.

This is where Albert Einstein served as a visiting scholar in the early 1930s, where J. Robert Oppenheimer consulted while siring the atomic bomb, where Linus Pauling determined how atoms form molecules, where Charles Richter helped give birth to the modern study of earthquakes.

It has produced 23 Nobel Prize winners ever since astronomer George Ellery Hale, the first director of the Mount Wilson Observatory, and others founded it. In 1920, they gave what had begun modestly in 1891 as Amos G. Throop University--a local arts and crafts school--a new name (California Institute of Technology), a fresh start in problem-solving and a vision that could see forever.

Once-per-weekday tours of the 124-acre campus are aimed mainly at prospective students (separate architectural tours require reservations and occur on the fourth Thursday of each month except July, August and December; because of Thanksgiving, November tours occur on the third Thursday).

A video that starts the tour celebrates Caltech’s centennial and rekindles the first impressions in 1931 of a freshman named Willy Fowler, who would become one of the school’s renowned physicists.

“I saw Robert Millikan and Albert Einstein in a heated discussion on the steps,” Fowler recalls. “I said, ‘Boy! This is the place to be!’ ”

1:45 p.m.: Tourists should report first to Caltech’s public relations and visitors center at 315 S. Hill Ave. Here, the 15-minute video explores not just the school’s history and pedigree but also its world-class reputation for student pranks.

Examples: Caltech insurgents reconfigured a UCLA card stunt at halftime of the 1984 Rose Bowl game to read: “GO CIT.” And during the seniors’ annual “Ditch Day” in 1987, others changed Los Angeles’ famed hillside letters--from HOLLYWOOD to CALTECH. Says one faculty member: “A lot of us are here because we can’t wait for the next prank.”

2 p.m.: It’s a sprawling campus of 100 buildings--grouped by scientific disciplines and arranged in some places to resemble Mediterranean plazas, with courtyards, arcades and handsome landscaping, eucalyptus trees and evergreens.

It’s unhurried and uncrowded here--owing to Caltech’s ratio of just three students for every faculty member.

Our student guide, a senior from Escondido, backpedals as she talks, leading a dozen visitors south on Hill Avenue past a mansion that serves as campus residence of Thomas E. Everhart, Caltech’s president since 1987.

She looks back on four exhausting years of academic pressure among peers who ranked in the top 1% of their high school classes. “Around here,” she says, “we tend to forget the real world.”

Turning right on San Pasqual Street, we soon enter North House--one of seven on-campus residence halls patterned not so much after fraternities but Oxford University’s family-style of housing. About 60% of Caltech’s students live on campus.

North House is a remodeled 1960s-vintage dormitory with bunk beds designed by students to relieve overcrowding. On the main floor is a room lined with about 60 personal computers. Each house has such a facility, with all terminals linked to a central campus-wide network and free electronic mail anywhere--a perk to students who loathe writing letters.

2:15 p.m.: A few steps beyond North House sits an impressive Italian Renaissance-style building named the Athenaeum, which serves faculty and staff. “It’s our version of an officers’ club,” the guide says.

With its archways, tile roof and courtyard, Athenaeum also has served as a location site for feature films such as “Beverly Hills Cop” (1984) and “The War of the Roses” (1989).

2:30 p.m.: We pass South House, a more elegant residence hall built in the 1930s, and the Winnett Student Center, a brick building that contains the bookstore, coffeehouse lounge, piano room and Caltech’s YMCA chapter.

Along a nearby sidewalk, a turn-of-the-century cannon looms--a three-ton relic of the Franco-Prussian War on loan from Southwestern Academy in nearby San Marino (and sometimes pilfered by prankish students from Harvey Mudd College in Claremont, the guide says).

A cannon blast (“harmless--but noisy,” school officials say) fires about six times a year to herald important events such as final-exams week and commencement.

2:45 p.m.: Farther along the walkway is a knot of buildings including the Firestone (applied mathematics and flight sciences) and Guggenheim (aeronautics and applied physics) laboratories.

The Guggenheim Laboratory, which once tested the late Howard Hughes’ Spruce Goose aircraft, contains wind- and shock-tunnels enabling the study of how aircraft perform at high speeds and high altitude.

3 p.m.: Near the west end of the campus, the nine-story Millikan Library (named for physicist Robert A. Millikan, who helped George Ellery Hale start Caltech on its new mission in 1921) dominates the landscape.

The library, completed in 1967, was built to withstand earthquakes of magnitude 8.0, officials say. During the 1971 Sylmar quake, the building survived, but countless books toppled along with their shelves (which now are bolted to walls).

Nearby is the Arms Laboratory (geological and planetary sciences), which is said to house the largest collection of gems and minerals in the Southwestern United States.

3:10 p.m.: Mudd Laboratory-South, at the school’s southwesternmost corner (California Boulevard and Wilson Avenue), cuts an even taller public profile than the Millikan Library.

It’s Caltech’s so-called Seismic Center, where Kate Hutton and other scientists hold court amid swarms of reporters and TV cameras after major Southern California earthquakes and aftershocks.

Here, instruments record an average of 30 earthquakes (mostly small) a day, the guide tells visitors. She points to cylinders of white paper nicknamed the “Pasadena Drum,” a seismograph whose wavy lines become jagged whenever a high-magnitude quake occurs.

“Not much is going on today,” she says, with relief.

3:15 p.m.: Near mid-campus sits a white circular building with a pointed roof. It’s Beckman Auditorium, scene of lectures, concerts, dance recitals and theatrical programs that attract crowds from across Greater Los Angeles.

Close by are the Beckman Institute, where biologists interact with chemists, and the Beckman Laboratories of Behavioral Biology, representing Caltech’s role as one of the first schools to conduct major studies of the brain and nervous system.

3:30 p.m.: At tour’s end, you can dodge the start of rush hour by strolling to the Pie ‘N Burger (913 E. California Blvd.), a down-home, family-style cafe which, like Caltech, is a neighborhood institution--popular with students and faculty for three decades. “My son likes it because they still make sodas there the old-fashioned way,” one Caltech employee says of the Pie ‘N Burger, 1 1/2 blocks from the campus. “They pour the syrup and mix it all up right in front of you.”

Where and When

What: Public tours of the Caltech campus. Public relations and visitors center, 315 S. Hill Ave., Pasadena.

When: 2 p.m. Mondays through Fridays (except on holidays or winter break), preceded by showing of video at 1:45 p.m. Separate architectural tours occur on the fourth Thursday of each month (except for July, August and December; because of Thanksgiving, November tours occur on the third Thursday).

Price: Free.

Call: (818) 395-6327.