Part I
When I was a boy, from time to time a recurring dream would infiltrate my sleep. In that dream, I would discover a secret doorway or staircase that led to a whole other floor of our house whose existence no one had suspected. It was a place of wonder and joy, with a paneled wood ceiling and specks of dust swimming lazily in the great slants of sunlight that barreled in through casement windows.
How to explain this dream? At the time, we lived in a comfortable duplex home. True, my brothers and I lived on the third floor, where the roofline made for inward sloping walls. Maybe I felt crowded by the architecture and my two often-rowdy brothers. Or perhaps, growing up as I did in an unobservant home, my dream of a hidden chamber was the religious impulse expressing itself.
Whatever the cause, the dream withered in adolescence and I grew up a scientific materialist. There was no room in my house for heaven, hell, or anything immaterial. But that has changed. In what I sincerely hope are the middle years of my life, I have rediscovered my secret room. And what is more important, I have done so through strictly rational, scientifically informed processes.
If this sounds like a conversion testimony, let me hasten to correct that impression. I remain a nontheistic skeptic committed to gaining knowledge about the world primarily through science and reason. Nevertheless, in the crucible of the science-religion dialogue, I have found facts and principles that point to something more than the merely material. More particularly, in the methods and findings of science itself I have discovered what I take to be the multiaxial nature of reality [1]. And while this epiphany has not led to any religious beliefs, it does perhaps create an architecture for the housing of many religions. I will try to explain.
Multiaxial reality amounts to a set of Big Claims. Let me specify them as clearly as I can, so as to make a juicy target for the slings and arrows of outraged monists.
Claim 1: Science demonstrates that, for any two or more observers, material reality differs. The laws of physics may be the same everywhere, but the available information varies from person to person. This scientific insight suggests that all human knowledge about the natural world, including its conscious participants, faces insurmountable limitations.
Claim 2: To secure its own rational justification, science must accept the metaphysical reality of certain fundamentals of logic, including mathematical reasoning. Additionally, I assert that, based on a longstanding physicalist definition of reality, there are rational grounds for accepting other metaphysical entities, including at a minimum, God [2].
Claim 3: Our best knowledge suggests that reality is multiaxial in nature. This means that, at a minimum, various metaphysical axes intersect with the natural world through the agency of human minds. A religious worldview typically takes the form of a metaphysical axis that runs through and extends beyond the natural world. From a third-person perspective, heterophenomenology [3] permits us to accept that metaphysical axis as independent yet consistent with many other metaphysical worldviews that intersect in the natural world.
Dallying With Time
The first of these may not appear very bold. After all, it's been nearly a century since Einstein introduced the physics of relativity to the world. The basic implications of his theory have been so well confirmed and digested that even a scribbler like myself can readily embrace the idea that if you are in motion, relative to me, I'll perceive your clock to run slower and your yardstick to shrink. What's more, there are plenty of commonplace reasons for believing that perspectives differ, even without resort to relativity. Your experience of the color green may be quite different from mine. However, the claim I'm making goes a bit farther. Based on a conventional understanding of relativity, I'm arguing that science demonstrates that some events that occur in your world can never, even in principle, be known in mine, and vice versa.
Before attempting to justify that strange-sounding assertion, let me back up to the clock and yardstick. The effects of relativity, though indisputable, cannot be discerned in normal human experience. Drivers at the Indy 500 don't have to resychronize their watches with the pit crew. Only if someone or something is traveling really, really fast does relativity kick in. At jet speed, you can just barely measure it. But measure it you can.
In October 1971, experimenters J.C. Hafele and R. E. Keating of the U.S. Naval Observatory put two pairs of atomic clocks on airliners bound in opposite directions. Atomic clocks are so amazingly accurate, they measure time in billionths of seconds, known as nanoseconds. Using Einstein's relativity theory, they predicted that the clocks flying around the world to the east would lose about 40 nanoseconds compared with the observatory's atomic clock. Conversely, they predicted that the clocks flying west would gain about 275 nanoseconds. After the circuits were completed, they found that the eastbound clocks had lost 59 nanoseconds, and the westbound clocks had gained 273 [4]. Both results were well within the experiment's margin of error. Vindication for Einstein and a lesson to pilots everywhere. Horace Greeley had it right: "Go West, young man!"
Of course, a pilot who insisted on flying only westward would find that after a million round-the-world trips, he had preserved only a couple of seconds' worth of youth. Even so, relativity remains crucially important to airline pilots everywhere. That's because nearly all airliners now rely on the Global Positioning Satellite system. And in GPS, relativity looms large.
As gravitational physicist Neil Ashby of the University of Colorado tells it, when the positioning satellites were first put into orbit, some engineers doubted the truth of relativity. They deliberately ignored the predicted effects of the satellites' relative motion and lower gravity. Within three weeks, Ashby reports, the clocks aboard the satellites were trailing behind earthbound clocks by so much that they would have soon required corrections of 38,000 nanoseconds a day [5]. Since the system works by comparing clocks to estimate distance, this relativistic anomaly presented a serious problem. To appreciate its magnitude, consider this remark from physicist Michael Fowler of the University of Virginia: "[A]n error of 100 nanoseconds or so could, for example, put an airplane off the runway in a blind landing [6].” Fortunately, the engineers had hedged their bets by putting aboard a correction device that could be - and was - activated from the ground.
All Reality is Local
I have digressed into spacetime dilation to make a point: the "error" in GPS is not really an error at all. It's a difference between two localities in the flow of time. Similarly, the set of events that constitute reality at any given moment differs from place to place. Let me explain. Among Einstein's many illuminating discoveries, none is more fascinating and frustrating than that of a universal speed limit. Put simply, nothing knowable can travel faster than the speed of light in a vacuum. To be sure, that covers a lot of ground: roughly 300,000 kilometers per second. For those of us used to doing 70 on the highway, it may be easier to remember this: the beams of light from your headlamps are whizzing ahead of you at about 700 million miles an hour. But in a universe as big as ours, the speed limit has palpable consequences. At this writing, as far as any residents of Alpha Centauri might be concerned, George W. Bush is not yet the president of the United States. It's not just that they don't know it. In an important sense, for our nearest stellar neighbors, 4.2 light years away, the 2000 U.S. election hasn't happened. To be blunt, there is no universal calendar of events. The farther away an object, the deeper it lies in the past. This has interesting implications for the future of our science and religion.
Light Cones, Light Bubbles
Physicists describe causally linked events as taking place within light cones. Lee Smolin, in his wonderfully intriguing book Three Roads to Quantum Gravity, offers this description:
"Since nothing can travel faster than light, the paths of light rays leaving the event define the outer limits of the causal future of an event. They form what we call the future light cone of an event. We call it a cone because, if we draw the picture so that space has only two dimensions ... it looks like a cone (7).”
It's a useful depiction, especially since it also serves to capture the events in the past that influenced a particular event. Still, I find it easier and more esthetically pleasing to picture an event - say, the announcement on CNN of the Supreme Court's decision in Bush v. Gore - as creating a light bubble. The bubble expands at the speed of light. Since the earth's radius is about 4,000 miles, the whole planet is engulfed in news within a few hundredths of a second. Of course, satellite relay and signal-processing add to the delay. That is why reporters in Iraq stare dumbly into the camera for several seconds after the East Coast anchor asks a question.
Mind the Gap
This might seem like a mere annoyance, but remember the lesson of GPS! Who can say that light cones won't be relevant to humanity in the future? Even now, in a trivial sense,