The old San Francisco home shook violently as two strong earthquakes ruptured the ground, one at a time. But in the dining room the visitors just laughed in delight - and hung on.

As they clung to strong railings, a chandelier swayed; a shelf of fancy dishes clattered and clashed; in a fishbowl the frightened fish's simulated water rocked like a wave; books on two shelves banged against each other; and on the wall a framed painting swung back and forth.

The house is part of a new earthquake exhibit and planetarium show set to open Saturday at the California Academy of Sciences. Its purpose is to offer a near real-life example of how the deadly quakes of 1906 and 1989 must have felt - and how any future temblor with a similar magnitude is bound to feel when it strikes, as someday it surely will.

During a preview last week, the two earthquakes shook everything in the room within a three-minute span - first 1989's Loma Prieta, then the '06 quake a few seconds later.

Although the house sits in the academy, visitors can look out a window and see Steiner Street and a view of the "Painted Ladies," those famed houses on Alamo Square. Their colors change to appear as they did in 1989 and 1906.

All the sounds outside change too: It's 1989 and from a distance, a stranded car's alarm sounds above the cheers of the crowd in Candlestick Park; a few seconds later, the clip-clop of a horse-drawn wagon and the noise of falling bricks tell visitors it's 1906.

The house will likely be the star attraction in the academy's new "Earthquake!" exhibit opening Saturday, but the planetarium is also strikingly vivid.

The production gives visitors the impression they are flying above the 800-mile length of the San Andreas fault as they hear and see the story of how Earth's continents were formed over hundreds of millions of years.

In sound and image, viewers learn about the deep structures beneath the Earth's crust where endlessly moving tectonic plates grind against each other, finally triggering the earthquakes we know.

It's the story of continental drift and, thus, the story of all earthquakes.

Other exhibits show movements of the continents are factors in shaping how plants and animals have evolved as Earth's crust alters and oceans form. There will be plenty of information and interactive displays, as well, about quake magnitudes, quake-proofing homes, surviving earthquakes, and how best to live when the shaking stops.

Ostriches may seem unrelated to earthquakes, but in one exhibit a flock of ostrich chicks illustrates how they and their closest relatives, the rheas, emus and kiwis, have evolved from a single common ancestor that lived before the breakup of an ancient continent, perhaps some 200 million years ago.

"The exhibit should give us all an appreciation of the geologic processes that formed the Earth and influence life today," said Peter Roopnarine, the academy's curator of geology and paleontology who helped assure its scientific accuracy. "Earthquakes are the violent events that that reveal the forces at work inside the Earth, and that's what we'll be showing clearly and vividly."

This article appeared on page C - 1 of the San Francisco Chronicle