The 4th Dimension

Looking up in Yosemite begins a reverie on Einstein.

by Harold Gilliam
San Francisco Chronicle - July 17, 2005

My wild fantasy about the Flatlanders and the Fourth Dimension did not come to me entirely on that first day in Yosemite, but the story began when I walked by the newsstand at Curry Village. I was compelled by a lifetime habit to check the headlines. I found no surprises there, and I instantly regretted that I had even looked.

Yosemite, I told myself, should be a retreat, an escape from the frenetic pressures of the world down below.

Yet after innumerable visits here over the years, I had come to suspect that Yosemite is more than a retreat. Like John Muir, I have always felt here a rare sense of exhilaration that I have never been able to explain.

But this time, during several days in the valley, I began to pick up some clues to that "mysterious enjoyment."

The first clue came as I strolled along the newly restored quarter-mile walkway to the foot of Yosemite Falls. Coveys of schoolkids, including one ebullient group from the South Bronx, were being shepherded along by teachers, who were explaining the natural history of the rocks, trees and waters. Visitors of all ages were gazing at the falls, and I heard exclamations in a half-dozen languages.

Yosemite Falls is a study in verticality with the upper fall dropping straight down through plumes of mist. Chronicle photo by Michael Macor

They were transfixed, as I have always been, by the upper fall, which from here seems to pour out of the sky. White jets plunge out from the valley rim and descend in a free fall of racing comets, trailing spray in continually changing shapes and motions. An afternoon breeze sometimes spreads the white water across the cliff until the fall is almost as horizontal as vertical.

As I watched the changing play of the falling water, it occurred to me that part of the spell of Yosemite is that we are impelled to look up. The awesome monument of El Capitan, the brooding presence of Half Dome (Muir once wondered metaphorically what great thoughts it might be thinking), the overhanging rim of Glacier Point, the cathedral-like upthrust of Sentinel Rock -- all require us to stretch our necks and contemplate unaccustomed verticality.

I recalled the old story of the imaginary Flatlanders, who live on a plane surface and cannot conceive of the vertical dimension. Draw a line around them and they are imprisoned.

Humans resemble Flatlanders in certain ways, particularly in cities, where our vision is usually constricted to the thin slice of reality near eye level. We are normally too busy with whatever is in front of our noses even to glance at the doings in the sky, for example. But here we are induced to look up and discover a new dimension of vision, not only the vertical but maybe something beyond.

Another clue came the next day, when with about 40 other curious visitors I joined a nature walk led by ranger Erik Westurland. As we walked across the valley floor, pausing at various view points, he told us about the Earth processes that created this place. Owing to a series of cold spells in the climate, beginning 2 million years ago, snows falling on the Sierra failed to melt and consolidated into glaciers. One mass of moving ice, several thousand feet deep, ponderously plowed its way down the shallow, V-shaped canyon of the Merced River, until it formed the deep U-shape of today's Yosemite.

Several times the glaciers moved through the valley. Each was melted by warming climates and left its own traces -- grooves on the granite walls and moraines that acted as dams, creating lakes from the melting ice. Over millennia, the lakes filled with sediments and became meadows. The ranger informed us that we were standing on lake sediments 2,000 feet deep.

When Muir arrived in the valley in 1868, the conventional wisdom was that the valley had been created when the floor dropped into an abyss -- and might drop again. But Muir saw the marks left by the glaciers and was the first to understand that the sculptor was ice.

It occurred to me, as the ranger told the glacier story, that we were contemplating another dimension -- beyond verticality. I remembered vaguely that Einstein had said something about a fourth dimension, beyond the familiar three. He called it "space-time."

The complications of his theory were beyond me, but some sense of a profound time dimension seemed to be what we were experiencing in contemplating the eons involved in producing this phenomenon of nature.

Like the usual limitation of our urban vision to whatever is at eye-level,

our sight-lines in time normally tend to be limited to the present moment. We live in a "now" culture. The headlines I had read on the Curry newsstand, like the daily barrages of news from television, radio and the Internet, focus our attention on the immediate events of the day, with little awareness that they are the result of sequences coming out of the past, and preludes to the future.

Timewise, we resemble the Flatlanders, imprisoned in our narrow view. But as Yosemite requires us to look up and discover the vertical dimension, it can also open up the time dimension. We can begin to see ourselves as a product of the planetary processes that created this valley and set in motion the successive waves of life that came here as the glaciers retreated.

It may be that we don't truly know who we are until we know how we came to be here, until we develop a sense of the long progression from the primeval protoplasm through seemingly random transmutations to the arrival of the human mind that creates cities, writes epics, composes symphonies and probes the mysteries of the universe.

El Capitan is an awesome monument rising from the floor to the rim of the valley. Chronicle photo by Michael Macor

The emotional high we feel here may stem from a conscious or unconscious awareness of our roots in the past, our kinship with the lichen on the granite, the grasses in these meadows, the oaks and pines in these woods, the deer and the bears. Yosemite makes extraordinarily visible -- in its sculptured walls, its amazing display of flowing waters and its abundance of living forms -- the life force that runs through all plants and creatures, great and small, and inspires the creative impulse in humans.

My ambulatory reverie was interrupted when the group paused in a meadow where most of the valley was visible, and ranger Westurland told us that the coming of the glaciers resulted from a global temperature drop of only a few degrees.

Questions from the group indicated that many of us were following that logic into the future. What would happen if the global temperature becomes a few degrees warmer, resulting from human activities? And what if the climate change were to take place, as most scientists believe possible, not in millennia but in decades?

The ranger didn't answer our questions but wisely let us draw our own conclusions. It seemed clear that our new awareness of the time dimension, displayed so vividly here, involved not only a recognition of our membership in the community of life on Earth but also our role as the first species with the power to have a virtual geologic impact on that community, possibly as drastic as the effect of the glaciers.

And it also occurred to me that our role involves the power to change course, the responsibility to develop a sustainable way of life in harmony with the natural processes of the Earth.

My new understanding of that fourth dimension was intensified by an intuitive awareness as I wandered through the meadows and groves where dogwood blossoms appeared like swarms of white butterflies in the spring-green foliage. Even during seasonal visitor peaks, it's still possible to walk on quiet trails away from the crowds. I followed the Merced River upstream to Happy Isles, where it roars over boulders in constantly changing shapes -- waterwheels, plumes, geysers, cascades, shooting jets and flying spray, in Muir's words, "a jubilee of waters."

Along with an endless procession of other visitors, I made the familiar pilgrimage up the Mist Trail, scaling the steep staircase of wet rocks alongside Vernal Fall, exhilarated by the baptism of cold spray from the thundering water.

At the top of the fall, near the brink of the 300-foot drop, I spotted a no-swimming sign and concluded that someone in the Park Service had a mordant sense of humor. Farther upstream, the Emerald Pool was not emerald at this season but white with the seasonal flood waters from Nevada Fall above -- and from the record snowpack in the high country.

On my last day, I walked past the Curry newsstand and checked the headlines again, this time without guilt. I could consider the human happenings of the moment in a new context. Yosemite now seemed to be not merely a retreat from everyday reality but a confrontation of a greater reality -- our relation to the living planet, the proper subject of our ultimate concern.

As I left the valley, that new perspective seemed confirmed by one final view of Yosemite Falls, pouring out of the sky like a river of light.