Authors: Carl Sagan
Ordinary hydrogen has a nucleus comprising a single proton. Heavy hydrogen, called deuterium, has a nucleus comprising one proton and one neutron. An astronomical telescope in Earth orbit called “Copernicus” has measured, for the first time, the amount of deuterium between the stars. Deuterium must have been made in the Big Bang in an amount that depends on the early density of the universe. The early density of the universe is connected with the present density of the universe. The amount of deuterium found by “Copernicus” implies a value to the early density of the universe and suggests that the present density is insufficient to prevent the universe from expanding forever.
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And what is said to be the best value of the Hubbell constant—which specifies how much faster more distant galaxies are receding from us than nearby ones—is consistent with this whole story.
Gott and his colleagues stressed that there may be loopholes in their argument, that it may be possible to hide intergalactic matter in ways which we could not then detect. Evidence for such missing mass has now begun to emerge. The High Energy Astronomical Observatories (HEAO) are a set of satellites orbiting the Earth and scanning the universe for particles and radiation that we cannot detect down here, under our thick
blanket of air. Satellites of this sort have detected intense emission of X-rays from clusters of galaxies, from intergalactic spaces where there was hitherto no hint of any matter. Extremely hot gas between the galaxies would be invisible to other experimental methods and therefore missed in the inventory of cosmic matter made by Gott and his colleagues. What is more, ground-based radio astronomical studies with the Arecibo Observatory in Puerto Rico have shown that the matter in galaxies extends far beyond the optical light from the apparent edges of galaxies. When we look at a photograph of a galaxy, we see an edge or periphery beyond which there is no apparent luminous matter. But the Arecibo radio telescope has found that the matter fades off extremely slowly and that there is substantial dark matter in the peripheries and exteriors of galaxies, which had been missed by previous surveys.
The amount of missing matter required to make the universe ultimately collapse is substantial. It is thirty times the matter in standard inventories such as Gott’s. But it may be that the dark gas and dust in the galactic outskirts, and the astonishingly hot gas glowing in X-rays between the galaxies, together constitute just enough matter to close the universe, prevent an expansion forever—but condemn us to an irrevocable end in a cosmic fireball 50 billion or 100 billion years hence. The issue is still teetering. The deuterium evidence points the other way. Our inventories of mass are still far from complete. But as new observational techniques develop we will have the capability of detecting more and more of any missing mass, and so it would seem that the pendulum is swinging toward a closed universe.
It is a good idea not to make up our minds prematurely on this issue. It is probably best not to let our personal preferences influence the decision. Rather, in the long tradition of successful science, we should permit nature to reveal the truth to us. But the pace of discovery is quickening. The nature of the universe emerging from modern experimental cosmology is very different from that of the ancient Greeks who speculated on the universe and the gods. If we have avoided anthropocentrism,
if we have truly and dispassionately considered all alternatives, it may be that in the next few decades we will, for the first time, rigorously determine the nature and fate of the universe. And then we shall see if Gott knows.
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But there is still a debate on how much deuterium can be made in the hot insides of stars and later spewed back into the interstellar gas. If this is substantial, the present deuterium abundance will have less impact on the density of the early universe.
It is as natural to man to die as to be born; and to a little infant, perhaps, the one is as painful as the other.
FRANCIS BACON
,
Of Death
(1612)
The most beautiful thing we can experience is the mysterious. It is the source of all true art and science. He to whom this emotion is a stranger, who can no longer wonder and stand rapt in awe, is as good as dead: his eyes are closed.… To know that what is impenetrable to us really exists, manifesting itself as the highest wisdom and the most radiant beauty which our dull facilities can comprehend only in the most primitive forms—this knowledge, this feeling, is at the center of true religiousness. In this sense, and in this sense only, I belong to the ranks of the devoutly religious men.
ALBERT EINSTEIN
,
What I Believe (1930)
WILLIAM WOLCOTT
died and went to heaven. Or so it seemed. Before being wheeled to the operating table, he had been reminded that the surgical procedure would entail a certain risk. The operation was a success, but just as the anaesthesia was wearing off his heart went into fibrillation and he died. It seemed to him that he had somehow left his body and was able to look down upon it, withered and pathetic, covered only by a sheet, lying on a hard and unforgiving surface. He was only a little sad, regarded his body one last time—from a great height, it seemed—and continued a kind of upward journey. While his surroundings had been suffused by a strange permeating darkness, he realized that things were now getting brighter—looking up, you might say. And then he was being illuminated from a distance, flooded with light. He entered a kind of radiant kingdom and there, just ahead of him, he could make out in silhouette, magnificently lit from behind, a great godlike figure whom he was now effortlessly approaching. Wolcott strained to make out His face…
And then awoke. In the hospital operating room where the defibrillation machine had been rushed to him, he had been resuscitated at the last possible moment. Actually, his heart had stopped, and by some definitions of this poorly understood process, he had died. Wolcott was certain that he
had
died, that he had been vouchsafed a glimpse of life after death and a confirmation of Judaeo-Christian theology.
Similar experiences, now widely documented by physicians and others, have occurred all over the world. These perithanatic, or near-death, epiphanies have been experienced not only by people of conventional Western religiosity but also by Hindus and Buddhists and skeptics. It seems plausible that many of our conventional ideas about heaven are derived from such near-death experiences, which must have been related regularly over the millennia. No news could have been more interesting or more hopeful than that of the traveler returned, the report that there is a voyage and a life after death,
that there is a God who awaits us, and that upon death we feel grateful and uplifted, awed and overwhelmed.
For all I know, these experiences may be just what they seem and a vindication of the pious faith that has taken such a pummeling from science in the past few centuries. Personally, I would be delighted if there were a life after death—especially if it permitted me to continue to learn about this world and others, if it gave me a chance to discover how history turns out. But I am also a scientist, so I think about what other explanations are possible. How could it be that people of all ages, cultures and eschatological predispositions have the
same sort
of near-death experience?
We know that similar experiences can be induced with fair regularity, cross-culturally, by psychedelic drugs.
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Out-of-body experiences are induced by dissociative anaesthetics such as the ketamines (2-[o-chlorophenyl]-2-[methylamino] cyclohexanones.) The illusion of flying is induced by atropine and other belladonna alkaloids, and these molecules, obtained, for example, from mandrake or jimson weed, have been used regularly by European witches and North American
curanderos
(“healers”) to experience, in the midst of
religious ecstasy, soaring and glorious flight. MDA (2,4-methylenedioxyamphetamine) tends to induce age regression, an accessing of experiences from youth and infancy which we had thought entirely forgotten. DMT (N,N-dimethyltryptamine) induces micropsia and macropsia, the sense of the world shrinking or expanding, respectively—a little like what happens to Alice after she obeys instructions on small containers reading “Eat me” or “Drink me.” LSD (lysergic acid diethylamide) induces a sense of union with the universe, as in the identification of Brahman with Atman in Hindu religious belief.
Can it really be that the Hindu mystical experience is pre-wired into us, requiring only 200 micrograms of LSD to be made manifest? If something like ketamine is released in times of mortal danger or near-death, and people returning from such an experience always provide the same account of heaven and God, then must there not be a sense in which Western as well as Eastern religions are hard-wired in the neuronal architecture of our brains?
It is difficult to see why evolution should have selected brains that are predisposed to such experiences, since no one seems to die or fail to reproduce from a want of mystic fervor. Might these drug-inducible experiences as well as the near-death epiphany be due merely to some evolutionarily neutral wiring defect in the brain which, by accident, occasionally brings forth altered perceptions of the world? That possibility, it seems to me, is extremely implausible, and perhaps no more than a desperate rationalist attempt to avoid a serious encounter with the mystical.
The only alternative, so far as I can see, is that every human being, without exception, has already shared an experience like that of those travelers who return from the land of death: the sensation of flight; the emergence from darkness into light; an experience in which, at least sometimes, a heroic figure can be dimly perceived, bathed in radiance and glory. There is only one common
experience that matches this description. It is called birth.
HIS NAME IS STANISLAV GROF
. In some pronunciations his first and last names rhyme. He is a physician and a psychiatrist who has, for more than twenty years, employed LSD and other psychedelic drugs in psychotherapy. His work long antedates the American drug culture, having begun in Prague, Czechoslovakia, in 1956 and continuing in recent years in the slightly different cultural setting of Baltimore, Maryland. Grof probably has more continuing scientific experience on the effects of psychedelic drugs on patients than anyone else.
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He stresses that whereas LSD can be used for recreational and aesthetic purposes, it can have other and more profound effects, one of which is the accurate recollection of perinatal experiences. “Perinatal” is a neologism for “around birth,” and is intended to apply not just to the time immediately after birth but to the time before as well. (It is a parallel construction to “perithanatic,” near-death.) He reports a large number of patients who, after a suitable number of sessions, actually re-experience rather than merely recollect profound experiences, long gone and considered intractable to our imperfect memories, from perinatal times. This is, in fact, a fairly common LSD experience, by no means limited to Grof’s patients.
Grof distinguishes four perinatal stages recovered under psychedelic therapy. Stage 1 is the blissful complacency of the child in the womb, free of all anxiety, the center of a small, dark, warm universe—a cosmos in an amniotic sac. In its intrauterine state the fetus seems to experience something very close to the oceanic ecstasy described by Freud as a fount of the religious
sensibility. The fetus is, of course, moving. Just before birth it is probably as alert, perhaps even more alert, than just after birth. It does not seem impossible that we may occasionally and imperfectly remember this Edenic, golden age, when every need—for food, oxygen, warmth and waste disposal—was satisfied before it was sensed, provided automatically by a superbly designed life-support system; and, in dim recollection years later, describe it as “being one with the universe.”
In Stage 2, the uterine contractions begin. The walls to which the amniotic sac is anchored, the foundation of the stable intrauterine environment, become traitorous. The fetus is dreadfully compressed. The universe seems to pulsate, a benign world suddenly converted into a cosmic torture chamber. The contractions may last intermittently for hours. As time goes on, they become more intense. No hope of surcease is offered. The fetus has done nothing to deserve such a fate, an innocent whose cosmos has turned upon it, administering seemingly endless agony. The severity of this experience is apparent to anyone who has seen a neonatal cranial distortion that is still evident days after birth. While I can understand a strong motivation to obliterate utterly any trace of this agony, might it not resurface under stress? Might not, Grof asks, the hazy and repressed memory of this experience prompt paranoid fantasies and explain our occasional human predilections for sadism and masochism, for an identification of assailant and victim, for that childlike zest for destruction in a world which, for all we know, may tomorrow become terrifyingly unpredictable and unreliable? Grof finds recollections in the next stage connected with images of tidal waves and earthquakes, the analogues in the physical world of the intrauterine betrayal.