Essays

by Gregory Benford

  A closed universe seems the ultimate doom. In all cosmological models, if the mass density of the universe exceeds the critical value, gravity inevitably wins. This is called a "closed" universe, because it has finite spatial volume, but no boundary. It is like a three dimensional analog of a sphere's surface. A bug on a ball can circumnavigate it, exploring all its surface and coming back to home, having crossed no barrier. So a starship could cruise around the universe and come home, having found no edge.

  A closed universe stars with a big bang (an initial singularity) and expands. Separation between galaxies grows linearly with time. Eventually the universal expansion of space-time will slow to a halt. Then a contraction will begin, accelerating as it goes, pressing galaxies closer together. The photons rattling around in this universe will increase in frequency, the opposite of the red shift we see now. Their blue shift means the sky gets brighter in time. Contraction of space-time shortens wavelengths, which increases light energy.

  Though stars will still age and die as the closed universe contracts, the background light will blue shift. No matter if life burrows into deep caverns, in time the heat of this light will fry it. Freeman Dyson remarked that the closed universe gave him "a feeling of claustrophobia, to imagine our whole existence confined within a box." He asked, "Is it conceivable that by intelligent intervention, converting matter into radiation to flow purposefully on a cosmic scale, we could break open a closed universe and change the topology of spacetime so that only a part of it would collapse and another would expand forever? I do not know the answer to this question."

  The answer seems to be that once collapse begins, a deterministic universe allows no escape for pockets of spacetime. Life cannot stop the squeezing.

  Some have embraced this searing death, when all implodes toward a point of infinite temperature. Frank Tipler of Tulane University sees it as a great opportunity. In those last seconds, collapse will not occur at the same rate in all directions. Chaos in the system will produce "gravitational shear" which drives temperature differences. Drawing between these temperature differences, life can harness power for its own use.

  Of course, such life will have to change its form to use such potentials; they will need hardier stuff than blood and bone. Ceramic-based forms could endure, or vibrant, self-contained plasma clouds --any tougher structure might work, as long as it can code information.

  This most basic definition of life, the ability to retain and manipulate information, means that the substrate supporting this does not matter, in the end. Of course, the style of thought of a silicon web feasting on the slopes of a volcano won't be that of a shrewd primate fresh from the veldt, but certain common patterns can transfer.

  Such life forms might be able to harness the compressive, final energies at that distant end, the Omega Point. Frank Tipler's The Physics of Immortality makes a case that a universal intelligence at the Omega Point will then confer a sort of immortality, by carrying out the computer simulation of all possible past intelligences. All possible earlier "people" will be resurrected, he thinks. This bizarre notion shows how cosmology blends into eschatology, the study of the ultimate fate of things, particularly of souls.

  I, too, find this scenario of final catastrophe daunting. Suppose, then, the universe is not so dense that it will ever reverse its expansion. Then we can foresee a long toiling twilight.

  Life based on solid matter will struggle to survive. To find energy, it will have to ride herd on and merge black holes themselves, force them to emit bursts of gravitational waves. In principle these waves can be harnessed, though of course we don't know how as yet. Only such fusions could yield fresh energy in a slumbering universe.

  High civilizations will rise, no doubt, mounted on the carcass of matter itself -- the ever-spreading legions of black holes. Entire galaxies will turn from reddening lanes of stars, into swarms of utterly dark gravitational singularities, the holes. Only by moving such masses, by extracting power through magnetic forces and the slow gyre of dissipating orbits, could life rule the dwindling resources of the ever-enlarging universe. Staying warm shall become the one great Law.

  Dyson has argued that in principle, the perceived time available to living forms can be made infinite. In this sense, immortality of a kind could mark the cold, stretching stages of the universal death.

  This assumes that we know all the significant physics, of course. Almost certainly, we do not. Our chimpanzee worldview may simply be unable to comprehend events on such vast time scales. Equally, though, chimpanzees will try, and keep trying.

  Since Dyson's pioneering work on these issues, yet more physics has emerged which we must take into account. About his vision of a swelling universe, its life force spent, hangs a great melancholy.

  For matter itself is doomed, as well. Even the fraction which escapes the holes, and learns to use them, is mortal. Its basic building block, the proton, decays. This takes unimaginably long -- current measurements suggest a proton lifetime of more than 10[sup 33] years. But decay seems inevitable, the executioner's sword descending with languid grace.

  Even so, something still survives. Not all matter dies, though with the proton gone everything we hold dear will disintegrate, atoms and animals alike. After the grand operas of mass and energy have played out their plots, the universal stage will clear to reveal the very smallest.

  The tiniest of particles -- the electron and its anti-particle, the positron -- shall live on, current theory suggests. No process of decay can find purchase on their infinitesimal scales, lever them apart into smaller fragments. The electron shall dance with its anti-twin in swarms: the lightest of all possible plasmas.

  By the time these are the sole players, the stage will have grown enormously. Each particle will find its nearest neighbor to be a full light-year away. They will have to bind together, sharing cooperatively, storing data in infinitesimally thin currents and charges. A single entity would have to be the size of a spiral arm, of a whole galaxy. Vaster than empires, and more slow.

  Plasmas held together by magnetic and electric fields are incredibly difficult to manage, rather like building a cage for jello out of rubber bands. But in principle, physics allows such magnetic loops and glowing spheres. We can see them in the short-lived phenomenon of ball lightning. More spectacularly, they occur on the sun, in glowing magnetic arches which can endure for weeks, a thousand kilometers high.

  Intelligence could conceivably dwell in such wispy magnetic consorts. Communication will take centuries . . . but to the slow thumping of the universal heart, that will be nothing.

  If life born to brute matter can find a way to incorporate itself into the electron-positron plasma, then it can last forever. This would be the last step in a migration from the very early forms, like us: rickety assemblies of water in tiny compartment cells, hung on a lattice of moving calcium rods.

  Life and intelligence will have to alter, remaking their basic structures from organic molecules to, say, animated crystalline sheets. Something like this may have happened before; some theorists believe Earthly life began in wet clay beds, and moved to organic molecules in a soupy sea only later.

  While the customary view of evolution does not speak of progress, there has been generally an increase of information transmitted forward to the next generation. Complexity increases in a given genus, order, class, etc. Once intelligence appears, or invades a wholly different medium, such "cognitive creatures" can direct their own evolution. Patterns will persist, even thrive, independent of the substrate.

  So perhaps this is the final answer to the significance of it all. In principle, life and structure, hopes and dreams and Shakespeare's Hamlet, can persist forever -- if life chooses to, and struggles. In that far future, dark beyond measure, plasma entities of immense size and torpid pace may drift through a supremely strange era, sure and serene, free at last of ancient enemies.

  Neither the thermodynamic dread of heat death nor gravity's gullet could then swallow them. Cosmology would
have done its work.

  As the universe swells, energy lessens, and the plasma life need only slow its pace to match. Mathematically, there are difficulties involved in arguing, as Dyson does, that the perceived span of order can be made infinite. The issue hinges on how information and energy scale with time. Assuming that Dyson's scaling is right, there is hope.

  By adjusting itself exactly to its ever-cooling environment, life -- of a sort -- can persist and dream fresh dreams. The Second Law of Thermodynamics says that disorder increases in every energy transaction. But the Second Law need not be not the Final Law.

  Such eerie descendants will have much to think about. They will be able to remember and relive in sharp detail the glory of the brief Early Time -- that distant, legendary era when matter brewed energy from crushing suns together. When all space was furiously hot, overflowing with boundless energy. When life dwelled in solid states, breathed in chilly atoms, and mere paltry planets formed a stage.

  Freeman Dyson once remarked to me, about these issues, that he felt the best possible universe was one of constant challenge. He preferred a future which made survival possible but not easy. We chimps, if coddled, get lazy and then stupid.

  The true far future is shrouded and mysterious. Still, I expect that he shall get his wish, and we shall not be bored.

  GREGORY BENFORD

  THE FIRE THIS TIME

  SCIENCE was invented once, and only once.

  This is a singularly striking fact of human history. There were many opportunities for science to emerge, in the sense that we know it -- the reasonably dispassionate search for objective, checkable troths about the physical world. The Egyptians and Babylonians had lots of rule-of-thumb engineering and geometry. The Romans could build magnificently. The Chinese invented paper, gunpowder, rockets, the great sailing vessels of the Ming era.

  Yet none devised the rather abstract rules which govern scientific discourse. No rival to Euclid's Elements. No deductive mathematics. No Chinese or Indian or African theorems or proofs before they learned from Euclid.

  Indeed, truly modern science emerged only half a millennium ago. The term "science," from the Latin, "to know," is less than two centuries old. Before that science existed but was called "natural philosophy." Science as we know it came at the hands of William of Ockham, Francis Bacon, and then the great experimenters, Galileo and his contemporaries. The crowning jewel was the systematic, mathematical description of the most classically serene part of the world, celestial dynamics, by Newton.

  They all built on the Greeks, who invented the basic idea of the method. Along the shore of that rough peninsula, over two thousand years ago, the methods of careful reasoning, always braced by consultation with the facts of the matter, evolved and won through.

  Not that all Greeks held to it, of course. Aristotle lusted after the great intellectual leaps. He was impatient with facts and seldom checked his many assertions. Simple enough, one would think, to see if a heavy ball of the same size as a light one fell to earth at a different rate. But it was nearly two thousand years before Galileo looked to see, and found the truth.

  I loved Greece and was immediately drawn to it. My first visit there led to an entire novel about Mycenean archeology, Artifact. I grew up on a warm sea's edge, and live in Laguna Beach, California now because I simply love the rub and scent of the sea. More, I admire the cutting clarity of the air--sharper than the Gulf coast where I grew up, but sharing a smell of brine and eternal organic consequence.

  I sometimes think that the Greeks developed their Euclidean certainties, their sharp visions of cause and circumscribed effect, because they lived in an air of razor clarity. The dry, lucid accuracies of Athenian air may have kindled in the ancient mind some vision of a realm beyond the raw rub of the day, a province of the eternal which obeyed finer laws, more graceful dynamics.

  I thought this particularly because I was preparing, in late October of 1993, the notes for a course in ethics which I would soon teach in the honors humanities program at the University of California, Irvine. (Usually ethics is strictly a matter for the humanists, but for the past five years I have served as the token scientist in the honors courses.) It struck me how strongly Plato believed in smooth certainties lying behind our rude world, the famous shadows on the cave wall analogy. Socrates believed in higher ethical laws, too, which men could but crudely glimpse and try to copy. Idealism emerged in the sharp air of civilization's morning.

  Somehow that city-state of a quarter million population produced an immense flowering in art, literature, philosophy- and science. Many cultures yield up art, music, and higher thought generally. But only the Greeks put together science. I wondered why.

  I saw the smoke as I went to my one PM lecture on a blustery Wednesday, October 27. The spire of oily black smoke was about seven miles inland, I judged, near the freeway, far from my home in Laguna Beach. Dry winds off the desert called the Santa Anas brought an eerie, skin-prick-ling apprehension to the sharp air.

  By the time I had held forth on turbulence theory for an hour and a half, a dark cloud loomed across all the southern horizon. The brush fire had swept to the sea. On the telephone my wife Joan said the smell was already heavy and asked me to come home.

  I tried to reach Laguna Beach by the Pacific Coast Highway, only to be turned back by a policeman at the campus edge. So I went south, looping the long way around, leaving the freeway and threading through surface streets. When I had bought my Mercedes 560 SL my son had deplored its excess power, quite ecologically unsound, and I had replied lightly that I wanted to "seize opportunities." Here was the chance: I cut through traffic, hoping to get ahead of the predictable wedge wanting the only access to town.

  I failed, of course. Traffic was chaotic. I took two hours to reach Monarch Bay, the community immediately south of Laguna Beach. At Monarch Bay the police stopped everyone. Smoke glowered across the entire horizon now.

  I left my car at 5:30 and hiked north, striking up a conversation with a man, Dave Adams, who was walking to his nearby home. I stopped there for a drink and heard that the high school had burned. Our house sits three hundred meters above the school. On the other hand, this was media wisdom, instantly discounted. I went on, hitchhiking and walking the five miles to central Laguna by seven PM. Police were turning everyone back but the acrid flavor in the air alarmed me, and the dark clouds blowing thickly out to sea seemed to come from our hill. The police stopped me several times. I always retreated, then worked my way around to another street and went on.

  I knew that Joan must have evacuated by then, but I had set out to come home and just kept at it, through the gathering pall. Maybe there was something I could do -fight the fire, water down the yard, rescue some precious memories...

  On Wendt Street, near the high school, a police car came cruising down, herding the few homeowners left. I ducked behind a stone wall. "Get out of my driveway!" a man wearing a headphone radio shouted at me. He waved a pistol wildly -- a part of me noted, .$2 revolver, finger on the trigger guard, probably knows how to handle it -- and I realized he perhaps mistook me for a looter. I ran behind the police car and down a street, following the narrow windings toward our hill. Night had fallen.

  I sprinted on -- excited, oblivious to choking smoke, sirens and hoarse cries. At the high school -untouched, of course -- I met fire teams and more police. Chaos. Flames leapt from our hill, a steady popping roar. Homes exploded in orange as their roofs burst open. Yellows and reds traced out the dark discords of walls collapsing, brush crackling, cinders churning up in cyclonic winds, orange motes in a fountain of air -then falling, bright tumbling fireworks. Ash swept through the streets like gray snow. Above it all a cowl of black smoke poured out to sea.

  I crossed the street and climbed up onto a high ledge and still could not see far enough up Mystic Canyon to make out our house. But all around it homes burned furiously. Our street, Skyline Drive, was a flaming artery both above and below our house.

  A fire warden sh
outed at me to get out. I hesitated, he shouted again, and I realized it was all over. At last I gave up our house and turned away. I had been rushing forward for several hours, intent on reaching home. That was impossible. I could do nothing in this inferno. I had not gotten in anybody's way, but I hadn't done any good, either. Working my way this close to the fires was risky, if only from the smoke I inhaled. Slowly I realized that I had been running on automatic, and all this was quite foolish.

  I retreated through deserted streets. I hitchhiked partway back out and a few miles south found a 7-Eleven open. An incongruous sight, bright beacon beside the exodus. I was parched, sagging. I went in and straight to the back to get a big container of cold tea.

  The store owner was in a heated argument with two men who wanted to get gasoline. Police had come by and ordered the pumps closed. Excited, the owner started rattling off Korean and one of the men grabbed him by the shin collar and pulled him halfway across the counter. More shouting. The owner got free and backed away and the rest of us in the store yelled at the two men. They swore at the owner but made no more moves.

  Plenty of talk then, accusations and retorts and barks of angry egos. I judged it was not going to get any worse so I left money on the counter and walked out with the tea. A block further south six motorcycle police from Newport Beach sat on their machines and watched people still leaving along the Coast Highway, their uniforms pressed and neat. They weren't interested in the 7-Eleven.

  I finished the tea before I reached the Adams home. They all watched the television news and I drank some more. My thirst would not go away. I sat and listened to the announcer declare that all homes in the Mystic Hills were lost. All. Confirmation sent me into a daze.

  I called friends, who reported that Joan had indeed evacuated town and come to them, and then went on to the refugee center. Dave Adams drove me to the center and I found Joan. She was in better shape mentally and physically than I. I sat on a curb and ate my first fast food burger ever, from a free canteen run by In 'n Out. It was improbably delicious.