Death By Black Hole Part 15

SECTION 7.

SCIENCE AND G.o.d.

WHEN WAYS OF KNOWING COLLIDE.

FORTY.

IN THE BEGINNING.

Physics describes the behavior of matter, energy, s.p.a.ce, and time, and the interplay among them in the universe. From what scientists have been able to determine, all biological and chemical phenomena are ruled by what those four characters in our cosmic drama do to one another. And so everything fundamental and familiar to us Earthlings begins with the laws of physics.

In almost any area of scientific inquiry, but especially in physics, the frontier of discovery lives at the extremes of measurement. At the extremes of matter, such as the neighborhood of a black hole, you find gravity badly warping the surrounding s.p.a.ce-time continuum. At the extremes of energy, you sustain thermonuclear fusion in the ten-million-degree cores of stars. And at every extreme imaginable, you get the outrageously hot, outrageously dense conditions that prevailed during the first few moments of the universe.

This essay was the winner of the 2005 Science Writing Award from the American Inst.i.tute of Physics.

Daily life, we're happy to report, is wholly devoid of extreme physics. On a normal morning, you get out of bed, wander around the house, eat something, dash out the front door. And, by day's end, your loved ones fully expect you to look no different from the way you did when you left and to return home in one piece. But imagine arriving at the office, walking into an overheated conference room for an important 10:00 A.M A.M. meeting, and suddenly losing all your electrons-or worse yet, having every atom of your body fly apart. Or suppose you're sitting in your office trying to get some work done by the light of your desk lamp and somebody flicks on the overhead light, causing your body to bounce randomly from wall to wall until you're jack-in-the-boxed out the window. Or what if you went to a sumo wrestling match after work and saw the two spherical gentlemen collide, disappear, then spontaneously become two beams of light?

If those scenes played out daily, then modern physics wouldn't look so bizarre, knowledge of its foundations would flow naturally from our life experience, and our loved ones probably would never let us go to work. Back in the early minutes of the universe, though, that stuff happened all the time. To envision it, and understand it, one has no choice but to establish a new form of common sense, an altered intuition about how physical laws apply to extremes of temperature, density, and pressure.

Enter the world of E=mc E=mc 2 2.

Albert Einstein first published a version of this famous equation in 1905 in a seminal research paper t.i.tled "On the Electrodynamics of Moving Bodies." Better known as the special theory of relativity, the concepts advanced in that paper forever changed our notions of s.p.a.ce and time. Einstein, then just 26 years old, offered further details about his tidy equation in a separate, remarkably short paper published later the same year: "Does the Inertia of a Body Depend on Its Energy Content?" To save you the effort of digging up the original article, designing an experiment, and testing the theory, the answer is "Yes." As Einstein wrote: If a body gives off the energy E in the form of radiation, its ma.s.s diminishes by E/c2.... The ma.s.s of a body is a measure of its energy-content; if the energy changes by E, the ma.s.s changes in the same sense. (1952, p. 71) (1952, p. 71) Uncertain as to the truth of his statement, he then suggested: It is not impossible that with bodies whose energy-content is variable to a high degree (e.g. with radium salts) the theory may be successfully put to the test. (1952, p. 71) (1952, p. 71) There you have it-the algebraic recipe for all occasions when you want to convert matter into energy or energy into matter. In those simple sentences, Einstein unwittingly gave astrophysicists a computational tool, E=mc E=mc2, that extends their reach from the universe as it now is, all the way back to infinitesimal fractions of a second after its birth. that extends their reach from the universe as it now is, all the way back to infinitesimal fractions of a second after its birth.

The most familiar form of energy is the photon, a ma.s.sless, irreducible particle of light. You are forever bathed in photons: from the Sun, the Moon, and the stars to your stove, your chandelier, and your night-light. So why don't you experience E=mc E=mc2 every day? The energy of visible-light photons falls far below that of the least ma.s.sive subatomic particles. There is nothing else those photons can become, and so they live happy, relatively uneventful lives. every day? The energy of visible-light photons falls far below that of the least ma.s.sive subatomic particles. There is nothing else those photons can become, and so they live happy, relatively uneventful lives.

Want to see some action? Start hanging around gamma-ray photons that have some real energy-at least 200,000 times more than that of visible photons. You'll quickly get sick and die of cancer, but before that happens you'll see pairs of electrons-one matter, the other antimatter; one of many dynamic duos in the particle universe-pop into existence where photons once roamed. As you watch, you will also see matter-antimatter pairs of electrons collide, annihilating each other and creating gamma-ray photons once again. Increase the light's energy by a factor of another 2,000, and you now have gamma rays with enough energy to turn susceptible people into the Hulk. But pairs of these photons now have enough energy to spontaneously create the more ma.s.sive neutrons, protons, and their antimatter partners.

High-energy photons don't hang out just anywhere. But the place needn't be imaginary. For gamma rays, almost any environment hotter than a few billion degrees will do just fine.

The cosmological significance of particles and energy packets trans.m.u.ting into each other is staggering. Currently the temperature of our expanding universe, calculated from measurements of the microwave bath of light that pervades all of s.p.a.ce, is a mere 2.73 degrees Kelvin. Like the photons of visible light, microwave photons are too cool to have any realistic ambitions to become a particle via E=mc E=mc2; in fact, there are no known particles they can spontaneously become. Yesterday, however, the universe was a little bit smaller and a little bit hotter. The day before, it was smaller and hotter still. Roll the clocks backward some more-say, 13.7 billion years-and you land squarely in the primordial soup of the big bang, a time when the temperature of the cosmos was high enough to be astrophysically interesting.

The way s.p.a.ce, time, matter, and energy behaved as the universe expanded and cooled from the beginning is one of the greatest stories ever told. But to explain what went on in that cosmic crucible, you must find a way to merge the four forces of nature into one, and find a way to reconcile two incompatible branches of physics: quantum mechanics (the science of the small) and general relativity (the science of the large).

Spurred by the successful marriage of quantum mechanics and electromagnetism in the mid-twentieth century, physicists set off on a race to blend quantum mechanics and general relativity (into a theory of quantum gravity). Although we haven't yet reached the finish line, we know exactly where the high hurdles are: during the "Planck era." That's the phase up to 10-43 seconds (one ten-million-trillion-trillion-trillionth of a second) after the beginning, and before the universe grew to 10 seconds (one ten-million-trillion-trillion-trillionth of a second) after the beginning, and before the universe grew to 10-35 meters (one hundred-billion-trillion-trillionth of a meter) across. The German physicist Max Planck, after whom these unimaginably small quant.i.ties are named, introduced the idea of quantized energy in 1900 and is generally credited with being the father of quantum mechanics. meters (one hundred-billion-trillion-trillionth of a meter) across. The German physicist Max Planck, after whom these unimaginably small quant.i.ties are named, introduced the idea of quantized energy in 1900 and is generally credited with being the father of quantum mechanics.

Not to worry, though. The clash between gravity and quantum mechanics poses no practical problem for the contemporary universe. Astrophysicists apply the tenets and tools of general relativity and quantum mechanics to very different cla.s.ses of problems. But in the beginning, during the Planck era, the large was small, and there must have been a kind of shotgun wedding between the two. Alas, the vows exchanged during that ceremony continue to elude us, and so no (known) laws of physics describe with any confidence the behavior of the universe during the brief interregnum.

At the end of the Planck era, however, gravity wriggled loose from the other, still-unified forces of nature, achieving an independent ident.i.ty nicely described by our current theories. As the universe aged through 10-35 seconds it continued to expand and cool, and what remained of the unified forces split into the electroweak and the strong nuclear forces. Later still, the electroweak force split into the electromagnetic and the weak nuclear forces, laying bare the four distinct forces we have come to know and love-with the weak force controlling radioactive decay, the strong force binding the nucleus, the electromagnetic force binding molecules, and gravity binding bulk matter. By now, the universe was a mere trillionth of a second old. Yet its transmogrified forces and other critical episodes had already imbued our universe with fundamental properties each worthy of its own book. seconds it continued to expand and cool, and what remained of the unified forces split into the electroweak and the strong nuclear forces. Later still, the electroweak force split into the electromagnetic and the weak nuclear forces, laying bare the four distinct forces we have come to know and love-with the weak force controlling radioactive decay, the strong force binding the nucleus, the electromagnetic force binding molecules, and gravity binding bulk matter. By now, the universe was a mere trillionth of a second old. Yet its transmogrified forces and other critical episodes had already imbued our universe with fundamental properties each worthy of its own book.

While the universe dragged on for its first trillionth of a second, the interplay of matter and energy was incessant. Shortly before, during, and after the strong and electroweak forces parted company, the universe was a seething ocean of quarks, leptons, and their antimatter siblings, along with bosons, the particles that enable their interactions. None of these particle families is thought to be divisible into anything smaller or more basic. Fundamental though they are, each comes in several species. The ordinary visible-light photon is a member of the boson family. The leptons most familiar to the nonphysicist are the electron and perhaps the neutrino; and the most familiar quarks are...well, there are no familiar quarks. Each species has been a.s.signed an abstract name that serves no real philological, philosophical, or pedagogical purpose except to distinguish it from the others: up and down, strange and charmed, and top and bottom.

Bosons, by the way, are simply named after the Indian scientist Satyendranath Bose. The word "lepton" derives from the Greek leptos leptos, meaning "light" or "small." "Quark," however, has a literary and far more imaginative origin. The physicist Murray Gell-Mann, who in 1964 proposed the existence of quarks, and who at the time thought the quark family had only three members, drew the name from a characteristically elusive line in James Joyce's Finnegans Wake Finnegans Wake: "Three quarks for Muster Mark!" One thing quarks do have going for them: all their names are simple-something chemists, biologists, and geologists seem incapable of achieving when naming their own stuff.

Quarks are quirky beasts. Unlike protons, each with an electric charge of +1, and electrons, with a charge of1, quarks have fractional charges that come in thirds. And you'll never catch a quark all by itself; it will always be clutching onto other quarks nearby. In fact, the force that keeps two (or more) of them together actually grows stronger the more you separate them-as if they were attached by some sort of subnuclear rubber band. Separate the quarks enough, the rubber band snaps and the stored energy summons E=mc E=mc2 to create a new quark at each end, leaving you back where you started. to create a new quark at each end, leaving you back where you started.

But during the quark-lepton era the universe was dense enough for the average separation between unattached quarks to rival the separation between attached quarks. Under those conditions, allegiance between adjacent quarks could not be unambiguously established, and they moved freely among themselves, in spite of being collectively bound to each other. The discovery of this state of matter, a kind of quark soup, was reported for the first time in 2002 by a team of physicists at the Brookhaven National Laboratories.

Strong theoretical evidence suggests that an episode in the very early universe, perhaps during one of the force splits, endowed the universe with a remarkable asymmetry, in which particles of matter barely outnumbered particles of antimatter by a billion-and-one to a billion. That small difference in population hardly got noticed amid the continuous creation, annihilation, and re-creation of quarks and antiquarks, electrons and antielectrons (better known as positrons), and neutrinos and antineutrinos. The odd man out had plenty of opportunities to find someone to annihilate with, and so did everybody else.

But not for much longer. As the cosmos continued to expand and cool, it became the size of the solar system, with the temperature dropping rapidly past a trillion degrees Kelvin.

A millionth of a second had pa.s.sed since the beginning.

This tepid universe was no longer hot enough or dense enough to cook quarks, and so they all grabbed dance partners, creating a permanent new family of heavy particles called hadrons (from the Greek hadros, hadros, meaning "thick"). That quark-to-hadron transition soon resulted in the emergence of protons and neutrons as well as other, less familiar heavy particles, all composed of various combinations of quark species. The slight matter-antimatter asymmetry afflicting the quark-lepton soup now pa.s.sed to the hadrons, but with extraordinary consequences. meaning "thick"). That quark-to-hadron transition soon resulted in the emergence of protons and neutrons as well as other, less familiar heavy particles, all composed of various combinations of quark species. The slight matter-antimatter asymmetry afflicting the quark-lepton soup now pa.s.sed to the hadrons, but with extraordinary consequences.

As the universe cooled, the amount of energy available for the spontaneous creation of basic particles dropped. During the hadron era, ambient photons could no longer invoke E=mc E=mc2 to manufacture quark-antiquark pairs. Not only that, the photons that emerged from all the remaining annihilations lost energy to the ever-expanding universe and dropped below the threshold required to create hadron-antihadron pairs. For every billion annihilations-leaving a billion photons in their wake-a single hadron survived. Those loners would ultimately get to have all the fun: serving as the source of galaxies, stars, planets, and people. to manufacture quark-antiquark pairs. Not only that, the photons that emerged from all the remaining annihilations lost energy to the ever-expanding universe and dropped below the threshold required to create hadron-antihadron pairs. For every billion annihilations-leaving a billion photons in their wake-a single hadron survived. Those loners would ultimately get to have all the fun: serving as the source of galaxies, stars, planets, and people.

Without the billion-and-one to a billion imbalance between matter and antimatter, all ma.s.s in the universe would have annihilated, leaving a cosmos made of photons and nothing else and nothing else-the ultimate let-there-be-light scenario.

By now, one second of time has pa.s.sed.

The universe has grown to a few light-years across, about the distance from the Sun to its closest neighboring stars. At a billion degrees, it's still plenty hot-and still able to cook electrons, which, along with their positron counterparts, continue to pop in and out of existence. But in the ever-expanding, ever-cooling universe, their days (seconds, really) are numbered. What was true for hadrons is true for electrons: eventually only one electron in a billion survives. The rest get annihilated, together with their antimatter sidekicks the positrons, in a sea of photons.

Right about now, one electron for every proton has been "frozen" into existence. As the cosmos continues to cool-dropping below 100 million degrees-protons fuse with protons as well as with neutrons, forming atomic nuclei and hatching a universe in which 90 percent of these nuclei are hydrogen and 10 percent are helium, along with trace amounts of deuterium, tritium, and lithium.

Two minutes have now pa.s.sed since the beginning.

Not for another 380,000 years does much happen to our particle soup. Throughout these millennia the temperature remains hot enough for electrons to roam free among the photons, batting them to and fro.

But all this freedom comes to an abrupt end when the temperature of the universe falls below 3,000 degrees Kelvin (about half the temperature of the Sun's surface), and all the electrons combine with free nuclei. The marriage leaves behind a ubiquitous bath of visible-light photons, completing the formation of particles and atoms in the primordial universe.

As the universe continues to expand, its photons continue to lose energy, dropping from visible light to infrared to microwaves.

As we will soon discuss in more detail, everywhere astrophysicists look we find an indelible fingerprint of 2.73-degree microwave photons, whose pattern on the sky retains a memory of the distribution of matter just before atoms formed. From this we can deduce many things, including the age and shape of the universe. And although atoms are now part of daily life, Einstein's equilibrious equation still has plenty of work to do-in particle accelerators, where matter-antimatter particle pairs are created routinely from energy fields; in the core of the Sun, where 4.4 million tons of matter are converted into energy every second; and in the cores of every other star.

It also manages to occupy itself near black holes, just outside their event horizons, where particle-antiparticle pairs can pop into existence at the expense of the black hole's formidable gravitational energy. Stephen Hawking first described that process in 1975, showing that the ma.s.s of a black hole can slowly evaporate by this mechanism. In other words, black holes are not entirely black. Today the phenomenon is known as Hawking radiation and is a reminder of the continued fertility of E=mc E=mc2.

But what happened before all this? What happened before the beginning?

Astrophysicists have no idea. Or, rather, our most creative ideas have little or no grounding in experimental science. Yet certain types of religious people tend to a.s.sert, with a tinge of smugness, that something something must have started it all: a force greater than all others, a source from which everything issues. A prime mover. must have started it all: a force greater than all others, a source from which everything issues. A prime mover.

In the mind of such a person, that something is, of course, G.o.d.

But what if the universe was always there, in a state or condition we have yet to identify-a multiverse, for instance? Or what if the universe, like its particles, just popped into existence from nothing?

Such replies usually satisfy n.o.body. Nonetheless, they remind us that ignorance is the natural state of mind for a research scientist on the ever-shifting frontier. People who believe they are ignorant of nothing have neither looked for, nor stumbled upon, the boundary between what is known and unknown in the cosmos. And therein lies a fascinating dichotomy. "The universe always was" goes unrecognized as a legitimate answer to "What was around before the beginning?" But for many religious people, the answer "G.o.d always was" is the obvious and pleasing answer to "What was around before G.o.d?"

No matter who you are, engaging in the quest to discover where and how things began tends to induce emotional fervor-as if knowing the beginning bestows upon you some form of fellowship with, or perhaps governance over, all that comes later. So what is true for life itself is no less true for the universe: knowing where you came from is no less important than knowing where you are going.

FORTY-ONE.

HOLY WARS.

At nearly every public lecture that I give on the universe, I try to reserve adequate time at the end for questions. The succession of subjects is predictable. First, the questions relate directly to the lecture. They next migrate to s.e.xy astrophysical subjects such as black holes, quasars, and the big bang. If I have enough time left over to answer all questions, and if the talk is in America, the subject eventually reaches G.o.d. Typical questions include, "Do scientists believe in G.o.d?" "Do you believe in G.o.d?" "Do your studies in astrophysics make you more or less religious?"

Publishers have come to learn that there is a lot of money in G.o.d, especially when the author is a scientist and when the book t.i.tle includes a direct juxtaposition of scientific and religious themes. Successful books include Robert Jastrow's G.o.d and the Astronomers G.o.d and the Astronomers, Leon M. Lederman's The G.o.d Particle The G.o.d Particle, Frank J. Tipler's The Physics of Immortality: Modern Cosmology, G.o.d, and the Resurrection of the Dead, The Physics of Immortality: Modern Cosmology, G.o.d, and the Resurrection of the Dead, and Paul Davies's two works and Paul Davies's two works G.o.d and the New Physics G.o.d and the New Physics and and The Mind of G.o.d The Mind of G.o.d. Each author is either an accomplished physicist or astrophysicist and, while the books are not strictly religious, they encourage the reader to bring G.o.d into conversations about astrophysics. Even the late Stephen Jay Gould, a Darwinian pitbull and devout agnostic, joined the t.i.tle parade with his work Rock of Ages: Science and Religion in the Fullness of Life Rock of Ages: Science and Religion in the Fullness of Life. The financial success of these published works indicates that you get bonus dollars from the American public if you are a scientist who openly talks about G.o.d.

After the publication of The Physics of Immortality The Physics of Immortality, which suggested whether the law of physics could allow you and your soul to exist long after you are gone from this world, Tipler's book tour included many well-paid lectures to Protestant religious groups. This lucrative subindustry has further blossomed in recent years due to efforts made by the wealthy founder of the Templeton investment fund, Sir John Templeton, to find harmony and consilience between science and religion. In addition to sponsoring workshops and conferences on the subject, the Templeton Foundation seeks out widely published religion-friendly scientists to receive an annual award whose cash value exceeds that of the n.o.bel Prize.

Let there be no doubt that as they are currently practiced, there is no common ground between science and religion. As was thoroughly doc.u.mented in the nineteenth-century tome A History of the Warfare of Science with Theology in Christendom A History of the Warfare of Science with Theology in Christendom, by the historian and onetime president of Cornell University Andrew D. White, history reveals a long and combative relationship between religion and science, depending on who was in control of society at the time. The claims of science rely on experimental verification, while the claims of religions rely on faith. These are irreconcilable approaches to knowing, which ensures an eternity of debate wherever and whenever the two camps meet. Although just as in hostage negotiations, it's probably best to keep both sides talking to each other.

The schism did not come about for want of earlier attempts to bring the two sides together. Great scientific minds, from Claudius Ptolemy of the second century to Isaac Newton of the seventeenth, invested their formidable intellects in attempts to deduce the nature of the universe from the statements and philosophies contained in religious writings. Indeed, by the time of his death, Newton had penned more words about G.o.d and religion than about the laws of physics, which included futile attempts to invoke the biblical chronology to understand and predict events in the natural world. Had any of these efforts succeeded, science and religion today might be largely indistinguishable.

The argument is simple. I have yet to see a successful prediction about the physical world that was inferred or extrapolated from the content of any religious doc.u.ment. Indeed, I can make an even stronger statement. Whenever people have tried to make accurate predictions about the physical world using religious doc.u.ments they have been famously wrong. By a prediction, I mean a precise statement about the untested behavior of objects or phenomena in the natural world, logged before before the event takes place. When your model predicts something only after it has happened then you have instead made a "postdiction." Postdictions are the backbone of most creation myths and, of course, of the the event takes place. When your model predicts something only after it has happened then you have instead made a "postdiction." Postdictions are the backbone of most creation myths and, of course, of the Just So Stories Just So Stories of Rudyard Kipling, where explanations of everyday phenomena explain what is already known. In the business of science, however, a hundred postdictions are barely worth a single successful prediction. of Rudyard Kipling, where explanations of everyday phenomena explain what is already known. In the business of science, however, a hundred postdictions are barely worth a single successful prediction.

TOPPING THE LIST of religious predictions are the perennial claims about when the world will end, none of which have yet proved true. A harmless enough exercise. But other claims and predictions have actually stalled or reversed the progress of science. We find a leading example in the trial of Galileo (which gets my vote for the trial of the millennium) where he showed the universe to be fundamentally different from the dominant views of the Catholic Church. In all fairness to the Inquisition, however, an Earth-centered universe made lots of sense observationally. With a full complement of epicycles to explain the peculiar motions of the planets against the background stars, the time-honored, Earth-centered model had conflicted with no known observations. This remained true long after Copernicus introduced his Sun-centered model of the universe a century earlier. The Earth-centric model was also aligned with the teachings of the Catholic Church and prevailing interpretations of the Bible, wherein Earth is unambiguously created before the Sun and the Moon as described in the first several verses of Genesis. If you were created first, then you must be in the center of all motion. Where else could you be? Furthermore, the Sun and Moon themselves were also presumed to be smooth orbs. Why would a perfect, omniscient deity create anything else? of religious predictions are the perennial claims about when the world will end, none of which have yet proved true. A harmless enough exercise. But other claims and predictions have actually stalled or reversed the progress of science. We find a leading example in the trial of Galileo (which gets my vote for the trial of the millennium) where he showed the universe to be fundamentally different from the dominant views of the Catholic Church. In all fairness to the Inquisition, however, an Earth-centered universe made lots of sense observationally. With a full complement of epicycles to explain the peculiar motions of the planets against the background stars, the time-honored, Earth-centered model had conflicted with no known observations. This remained true long after Copernicus introduced his Sun-centered model of the universe a century earlier. The Earth-centric model was also aligned with the teachings of the Catholic Church and prevailing interpretations of the Bible, wherein Earth is unambiguously created before the Sun and the Moon as described in the first several verses of Genesis. If you were created first, then you must be in the center of all motion. Where else could you be? Furthermore, the Sun and Moon themselves were also presumed to be smooth orbs. Why would a perfect, omniscient deity create anything else?

All this changed, of course, with the invention of the telescope and Galileo's observations of the heavens. The new optical device revealed aspects of the cosmos that strongly conflicted with people's conceptions of an Earth-centered, blemish-free, divine universe: The Moon's surface was b.u.mpy and rocky; the Sun's surface had spots that moved across its surface; Jupiter had moons of its own that orbited Jupiter and not Earth; and Venus went through phases, just like the Moon. For his radical discoveries, which shook Christendom-and for being a pompous jerk about it-Galileo was put on trial, found guilty of heresy, and sentenced to house arrest. This was mild punishment when one considers what happened to the monk Giordano Bruno. A few decades earlier Bruno had been found guilty of heresy, and then burned at the stake, for suggesting that Earth may not be the only place in the universe that harbors life.

I do not mean to imply that competent scientists, soundly following the scientific method, have not also been famously wrong. They have. Most scientific claims made on the frontier will ultimately be disproved, due primarily to bad or incomplete data, and occasionally to blunder. But the scientific method, which allows for expeditions down intellectual dead ends, also promotes ideas, models, and predictive theories that can be spectacularly correct. No other enterprise in the history of human thought has been as successful at decoding the ways and means of the universe.

Science is occasionally accused of being a closed-minded or stubborn enterprise. Often people make such accusations when they see scientists swiftly discount astrology, the paranormal, Sasquatch sightings, and other areas of human interest that routinely fail double-blind tests or that possess a dearth of reliable evidence. But don't be offended. Scientists apply this same level of skepticism to ordinary claims in the professional research journals. The standards are identical. Look what happened when the Utah chemists B. Stanley Pons and Martin Fleischmann claimed in a press conference to have created "cold" nuclear fusion on their laboratory table. Scientists acted swiftly and skeptically. Within days of the announcement it was clear that no one could replicate the cold fusion results that Pons and Fleischmann claimed. Their work was summarily dismissed. Similar plot lines unfold almost daily (minus the press conferences) for nearly every new scientific claim. The ones you hear about tend to be only those that could affect the economy.

WITH SCIENTISTS EXHIBITING such strong levels of skepticism, some people may be surprised to learn that scientists heap their largest rewards and praises upon those who do, in fact, discover flaws in established paradigms. These same rewards also go to those who create new ways to understand the universe. Nearly all famous scientists, pick your favorite one, have been so praised in their own lifetimes. This path to success in one's professional career is ant.i.thetical to almost every other human establishment-especially to religion. such strong levels of skepticism, some people may be surprised to learn that scientists heap their largest rewards and praises upon those who do, in fact, discover flaws in established paradigms. These same rewards also go to those who create new ways to understand the universe. Nearly all famous scientists, pick your favorite one, have been so praised in their own lifetimes. This path to success in one's professional career is ant.i.thetical to almost every other human establishment-especially to religion.

None of this is to say that the world does not contain religious scientists. In a recent survey of religious beliefs among math and science professionals (Larson and Witham 1998), 65 percent of the mathematicians (the highest rate) declared themselves to be religious, as did 22 percent of the physicists and astronomers (the lowest rate). The national average among all scientists was around 40 percent and has remained largely unchanged over the past century. For reference, about 90 percent of the American public claims to be religious (among the highest in Western society), so either nonreligious people are drawn to science or studying science makes you less religious.

But what of those scientists who are religious? Successful researchers do not get their science from their religious beliefs. On the other hand, the methods of science currently have little or nothing to contribute to ethics, inspiration, morals, beauty, love, hate, or aesthetics. These are vital elements of civilized life and are central to the concerns of nearly every religion. What it all means is that for many scientists there is no conflict of interest.

As we will soon see in detail, when scientists do talk about G.o.d, they typically invoke him at the boundaries of knowledge where we should be most humble and where our sense of wonder is greatest.

Can one grow tired of wonderment?

In the thirteenth century, Alfonso the Wise (Alfonso X), the king of Spain, who also happened to be an accomplished academician, was frustrated by the complexity of Ptolemy's epicycles accounting for the geocentric universe. Being less humble than others on the frontier, Alfonso once mused, "Had I been around at the creation, I would have given some useful hints for the better ordering of the universe" (Carlyle 2004, Book II, Chapter VII).

In full agreement with King Alfonso's frustrations with the universe, Albert Einstein noted in a letter to a colleague, "If G.o.d created the world, his primary worry was certainly not to make its understanding easy for us" (1954). When Einstein could not figure out how or why a deterministic universe could require the probabilistic formalisms of quantum mechanics, he mused, "It is hard to sneak a look at G.o.d's cards. But that He would choose to play dice with the world...is something that I cannot believe for a single moment" (Frank 2002, p. 208). When an experimental result was shown to Einstein that, if correct, would have disproved his new theory of gravity Einstein commented, "The Lord is subtle, but malicious He is not" (Frank 2002, p. 285). The Danish physicist Niels Bohr, a contemporary of Einstein, heard one too many of Einstein's G.o.d-remarks and declared that Einstein should stop telling G.o.d what to do! (Gleick 1999) Today, you hear the occasional astrophysicist (maybe one in a hundred) publicly invoke G.o.d when asked where did all our laws of physics come from or what was around before the big bang. As we have come to antic.i.p.ate, these questions comprise the modern frontier of cosmic discovery and, at the moment, they transcend the answers our available data and theories can supply. Some promising ideas, such as inflationary cosmology and string theory, already exist. These could ultimately provide the answers to those questions, further pushing back our boundary of awe.

My personal views are entirely pragmatic and partly resonate with those of Galileo who, during his trial, is credited with saying, "The Bible tells you how to go to heaven, not how the heavens go" (Drake 1957, p. 186). Galileo further noted, in a 1615 letter to the Grand d.u.c.h.ess of Tuscany, "In my mind G.o.d wrote two books. The first book is the Bible, where humans can find the answers to their questions on values and morals. The second book of G.o.d is the book of nature, which allows humans to use observation and experiment to answer our own questions about the universe" (Drake 1957, p. 173).

I simply go with what works. And what works is the healthy skepticism embodied in scientific method. Believe me, if the Bible had ever been shown to be a rich source of scientific answers and understanding, we would be mining it daily for cosmic discovery. Yet my vocabulary of scientific inspiration strongly overlaps with that of religious enthusiasts. I, like others, am humbled in the presence of the objects and phenomena of our universe. And I go misty with admiration for its splendor. But I do so knowing and accepting that if I propose a G.o.d who graces our valley of unknowns, the day may come, empowered by the advance of science, when no more valleys remain.

FORTY-TWO.

THE PERIMETER OF IGNORANCE.

Writing in centuries past, many scientists felt compelled to wax poetic about cosmic mysteries and G.o.d's handiwork. Perhaps one should not be surprised at this: most scientists back then, as well as many scientists today, identify themselves as spiritually devout.

But a careful reading of older texts, particularly those concerned with the universe itself, shows that the authors invoke divinity only when they reach the boundaries of their understanding. They appeal to a higher power only when staring into the ocean of their own ignorance. They call on G.o.d only from the lonely and precarious edge of incomprehension. Where they feel certain about their explanations, however, G.o.d gets hardly a mention.

Let's start at the top. Isaac Newton was one of the greatest intellects the world has ever seen. His laws of motion and his universal law of gravitation, conceived in the mid-seventeenth century, account for cosmic phenomena that had eluded philosophers for millennia. Through those laws, one could understand the gravitational attraction of bodies in a system, and thus come to understand orbits.

Newton's law of gravity enables you to calculate the force of attraction between any two objects. If you introduce a third object, then each one attracts the other two, and the orbits they trace become much harder to compute. Add another object, and another, and another, and soon you have the planets in our solar system. Earth and the Sun pull on each other, but Jupiter also pulls on Earth, Saturn pulls on Earth, Mars pulls on Earth, Jupiter pulls on Saturn, Saturn pulls on Mars, and on and on.

Newton feared that all this pulling would render the orbits in the solar system unstable. His equations indicated that the planets should long ago have either fallen into the Sun or flown the coop-leaving the Sun, in either case, devoid of planets. Yet the solar system, as well as the larger cosmos, appeared to be the very model of order and durability. So Newton, in his greatest work, the Principia, Principia, concludes that G.o.d must occasionally step in and make things right: concludes that G.o.d must occasionally step in and make things right: The six primary Planets are revolv'd about the Sun, in circles concentric with the Sun, and with motions directed towards the same parts, and almost in the same plane.... But it is not to be conceived that mere mechanical causes could give birth to so many regular motions.... This most beautiful System of the Sun, Planets, and Comets, could only proceed from the counsel and dominion of an intelligent and powerful Being. (1992, p. 544) (1992, p. 544) In the Principia, Principia, Newton distinguishes between hypotheses and experimental philosophy, and declares, "Hypotheses, whether metaphysical or physical, whether of occult qualities or mechanical, have no place in experimental philosophy" (p. 547). What he wants is data, "inferr'd from the phaenomena." But in the absence of data, at the border between what he could explain and what he could only honor-the causes he could identify and those he could not-Newton rapturously invokes G.o.d: Newton distinguishes between hypotheses and experimental philosophy, and declares, "Hypotheses, whether metaphysical or physical, whether of occult qualities or mechanical, have no place in experimental philosophy" (p. 547). What he wants is data, "inferr'd from the phaenomena." But in the absence of data, at the border between what he could explain and what he could only honor-the causes he could identify and those he could not-Newton rapturously invokes G.o.d: Eternal and Infinite, Omnipotent and Omniscient;...he governs all things, and knows all things that are or can be done.... We know him only by his most wise and excellent contrivances of things, and final causes; we admire him for his perfections; but we reverence and adore him on account of his dominion. (p. 545) (p. 545) A century later, the French astronomer and mathematician Pierre-Simon Laplace confronted Newton's dilemma of unstable orbits head-on. Rather than view the mysterious stability of the solar system as the unknowable work of G.o.d, Laplace declared it a scientific challenge. In his multipart masterpiece, Traite de mecanique celeste Traite de mecanique celeste, the first volume of which appeared in 1799, Laplace demonstrates that the solar system is stable over periods of time longer than Newton could predict. To do so, Laplace pioneered a new kind of mathematics called perturbation theory, which enabled him to examine the c.u.mulative effects of many small forces. According to an oft-repeated but probably embellished account, when Laplace gave a copy of Traite de mecanique celeste Traite de mecanique celeste to his physics-literate friend Napoleon Bonaparte, Napoleon asked him what role G.o.d played in the construction and regulation of the heavens. "Sire," Laplace replied, "I had no need of that hypothesis" (DeMorgan 1872). to his physics-literate friend Napoleon Bonaparte, Napoleon asked him what role G.o.d played in the construction and regulation of the heavens. "Sire," Laplace replied, "I had no need of that hypothesis" (DeMorgan 1872).

LAPLACE NOTWITHSTANDING, plenty of scientists besides Newton have called on G.o.d-or the G.o.ds-wherever their comprehension fades to ignorance. Consider the second-century A.D A.D. Alexandrian astronomer Ptolemy. Armed with a description, but no real understanding, of what the planets were doing up there, he could not contain his religious fervor and scribbled this note in the margin of his Almagest Almagest: I know that I am mortal by nature, and ephemeral; but when I trace, at my pleasure, the windings to and fro of the heavenly bodies, I no longer touch Earth with my feet: I stand in the presence of Zeus himself and take my fill of ambrosia.

Or consider the seventeenth-century Dutch astronomer Christiaan Huygens, whose achievements include constructing the first working pendulum clock and discovering the rings of Saturn. In his charming book The Celestial Worlds Discover'd, The Celestial Worlds Discover'd, posthumously published in 1698, most of the opening chapter celebrates all that was then known of planetary orbits, shapes, and sizes, as well as the planets' relative brightness and presumed rockiness. The book even includes foldout charts ill.u.s.trating the structure of the solar system. G.o.d is absent from this discussion-even though a mere century earlier, before Newton's achievements, planetary orbits were supreme mysteries. posthumously published in 1698, most of the opening chapter celebrates all that was then known of planetary orbits, shapes, and sizes, as well as the planets' relative brightness and presumed rockiness. The book even includes foldout charts ill.u.s.trating the structure of the solar system. G.o.d is absent from this discussion-even though a mere century earlier, before Newton's achievements, planetary orbits were supreme mysteries.

Celestial Worlds also brims with speculations about life in the solar system, and that's where Huygens raises questions to which he has no answer. That's where he mentions the biological conundrums of the day, such as the origin of life's complexity. And sure enough, because seventeenth-century physics was more advanced than seventeenth-century biology, Huygens invokes the hand of G.o.d only when he talks about biology: also brims with speculations about life in the solar system, and that's where Huygens raises questions to which he has no answer. That's where he mentions the biological conundrums of the day, such as the origin of life's complexity. And sure enough, because seventeenth-century physics was more advanced than seventeenth-century biology, Huygens invokes the hand of G.o.d only when he talks about biology: I suppose no body will deny but that there's somewhat more of Contrivance, somewhat more of Miracle in the production and growth of Plants and Animals than in lifeless heaps of inanimate Bodies.... For the finger of G.o.d, and the Wisdom of Divine Providence, is in them much more clearly manifested than in the other. (p. 20) (p. 20) Today secular philosophers call that kind of divine invocation "G.o.d of the gaps"-which comes in handy, because there has never been a shortage of gaps in people's knowledge.

AS REVERENT AS Newton, Huygens, and other great scientists of earlier centuries may have been, they were also empiricists. They did not retreat from the conclusions their evidence forced them to draw, and when their discoveries conflicted with prevailing articles of faith, they upheld the discoveries. That doesn't mean it was easy: sometimes they met fierce opposition, as did Galileo, who had to defend his telescopic evidence against formidable objections drawn from both scripture and "common" sense. Newton, Huygens, and other great scientists of earlier centuries may have been, they were also empiricists. They did not retreat from the conclusions their evidence forced them to draw, and when their discoveries conflicted with prevailing articles of faith, they upheld the discoveries. That doesn't mean it was easy: sometimes they met fierce opposition, as did Galileo, who had to defend his telescopic evidence against formidable objections drawn from both scripture and "common" sense.

Galileo clearly distinguished the role of religion from the role of science. To him, religion was the service of G.o.d and the salvation of souls, whereas science was the source of exact observations and demonstrated truths. In his 1615 letter to the Grand d.u.c.h.ess Christina of Tuscany he leaves no doubt about where he stood on the literal word of the Holy Writ: In expounding the Bible if one were always to confine oneself to the unadorned grammatical meaning, one might fall into error....Nothing physical which...demonstrations prove to us, ought to be called in question (much less condemned) upon the testimony of biblical pa.s.sages which may have some different meaning beneath their words....I do not feel obliged to believe that the same G.o.d who has endowed us with senses, reason and intellect has intended us to forgo their use. (Venturi 1818, p. 222) (Venturi 1818, p. 222) A rare exception among scientists, Galileo saw the unknown as a place to explore rather than as an eternal mystery controlled by the hand of G.o.d.

As long as the celestial sphere was generally regarded as the domain of the divine, the fact that mere mortals could not explain its workings could safely be cited as proof of the higher wisdom and power of G.o.d. But beginning in the sixteenth century, the work of Copernicus, Kepler, Galileo, and Newton-not to mention Maxwell, Heisenberg, Einstein, and everybody else who discovered fundamental laws of physics-provided rational explanations for an increasing range of phenomena. Little by little, the universe was subjected to the methods and tools of science, and became a demonstrably knowable place.