Читать книгу Beyond Biocentrism - Robert Lanza - Страница 10

IN THE BEGINNING . . .

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All is change; all yields its place and goes.

—Euripides (c. 416 b.c.e.)

No matter what picture of the universe one embraces, time seems to play a key role. Indeed, our existing models are so thoroughly time based, they can neither be understood nor disproved without also understanding time itself. Thus we must tackle it before anything else.

This is no mere philosophical matter. It goes to the heart of our perceptions and lies at the fulcrum between the observer and nature. Certainly, we use time constantly. We make appointments and look forward to vacation plans, and some of us fret about the afterlife. If there is one big difference between people and animals, it is not that we are unafraid of vacuum cleaners. It is that we are time obsessed.

On one level, what we commonly mean by time is inarguably real. Our car’s GPS announces that if we stay on this highway we will reach Cleveland in 3 hours and 48 minutes. And we do. Moreover, while we do that, countless other events unfold in our bodies and elsewhere on the Earth.

Yet this agreed-upon interval is, on closer inspection, as fishy and intangible as the question of what exactly happened at midnight on New Year’s Eve.

The question of time has tormented philosophers for millennia, and this torture shows no signs of abating. Happily, unlike the intricacies of, say, Middle East politics, here we have only two contrasting viewpoints.

One is the opinion held by such noted smart people as Isaac Newton, who saw time as part of the fundamental structure of the universe. He believed it to be inherently real. If so, time constitutes its own dimension and stands separate from events, which unfold sequentially within its matrix. This is probably how most people view time.

The opposing view, argued for centuries by other smart people such as Immanuel Kant, is that time is not an actual entity. It is not a kind of “container” that events “move through.” In this view, there is no flow to time. Rather, it’s a framework devised by human observers as they attempt to give organization and structure to the vast labyrinth of information whirling in their minds.

If this latter view is true, and time is only a kind of intellectual framework along the lines of our numbering systems or the way we order things spatially, then it certainly cannot be “traveled,” nor can it be measured on its own.

This means that clocks do not determine or keep track of time, but merely offer evenly spaced events as one digital number is replaced by another, or a minute hand is now here and now there. While these events proceed, other reliable rhythms simultaneously unfold elsewhere. And, of course, the lengths between each tick and tock are arbitrary, having been agreed upon by human council rather than some decree of nature.

The tick-tock idea began with Sun-based changes observed by people occupying a far more outdoorsy world than today’s. Sumerians and Babylonians more than six thousand years ago utilized the concepts of “day” and “year” and “month.” Soon after, the ancient Hindus defined specific units of time such as the kālá, which corresponds to 144 seconds.

The Hindus created a dizzying variety of intervals. At either end of their time spectrum the units were so extreme, they were useless in practical terms—and close to incomprehensible. These included the Paramaṇu, with a length of about 17 millionths of a second, and the Maha-Manvantara, which is 311.04 trillion years. Their long-interval units meshed with their creation and destruction myths, in which the cosmos undergoes cycles of clarity alternating with periods of human darkness, each called a yuga.

More practically, the ancient agrarian world relied on seasonal ways of reckoning, and these cycles were determined with amazing accuracy in civilizations like the Maya. Smaller units than months and days trickled into everyday usefulness, first with the creation of the dripping-water or falling-sand hourglass, and later the discovery of the pendulum effect by Galileo Galilei. In 1582 he noticed that the chandeliers hanging from long chains in the Piazza del Duomo kept swaying back and forth in the same period regardless of the swing’s amplitude, and—following an impressive bit of procrastination—wrote about this in 1602. This effect, experienced by children in playgrounds, amounts to the fact that when a parent gives a child a strong push, the swing’s period of travel from one end of its oscillation to the other is no different from when she is just sitting quietly with the swing barely moving at all.

The period is basically determined by the length of the chain, a property called isochronism. It turned out, a string or chain 39 inches long produces a back-and-forth period of exactly 2 seconds. It wasn’t long before this principle was utilized in grandfather clocks, whose long metal rods, just over 6 feet, ticked off near-perfect seconds.

Portable timekeeping took a leap with the invention of the balance spring watch in the second half of the seventeenth century, thanks to breakthroughs by Robert Hooke and Christiaan Huygens. Then accuracy skyrocketed after the 1880 discovery by the Curie brothers, Jacques and Pierre, that quartz crystals naturally vibrate when a bit of electricity is applied to them. If cut to a particular size and shape, they’ll reliably oscillate 32,768 times a second, which is a “power of 2”—it’s 2 multiplied by itself 15 times over. An electronic circuit has no trouble counting these oscillations and thus marking off evenly spaced seconds. This ultimately made precise portable timepieces—the quartz movement still utilized today—cheaply available beginning in 1969. With everyone now able to agree on the “right time,” the busy modern world with its appointments and scheduling settled into a shared, time-focused reality.

Through it all, however, the fact of pendulum swings, mechanical balance beam oscillations, and quartz vibrations was still no evidence of time. They all merely provided regular repetitive motions. One could then compare some repetitive events with others. One could notice, for example, that while a grandfather clock pendulum makes 1,800 swings, a candle might burn down 1 inch, and Earth would turn one-forty-eighth of a full rotation. Certainly, one could call the elapsing of all these events “a half hour,” but that didn’t mean that the time period had some independent reality, like a watermelon.

Then the whole business suddenly grew much odder with the discovery that some events could start unfolding faster than they had before, relative to others. Things started to become seriously disconcerting with Einstein’s strange but grudgingly logical ideas that he incorporated into both his special and general relativity theories of 1905 and 1915, respectively. In them, Einstein elaborated on and explained curiosities and paradoxes noted in the preceding decades by George FitzGerald and Hendrik Lorentz. In a nutshell, a totally unexpected revelation emerged: Even if time is an actual entity, it cannot be a constant like lightspeed or gravity. It flows at different rates. The presence of a gravitational field retards the passage of time, as does rapid motion.

We’re intuitively ignorant of this because we all attended a high school where everybody hung out in the same gravitational field—and never, even in our wildest teenage years, sped our car in a joyride faster than an eight-millionth of the speed of light. Because one must go 87 percent of lightspeed to feel time slow by half its normal rate, we’ve never even come close to directly experiencing time’s fickleness—a function of our still-sluggish ground vehicles rather than any personal wisdom.

Astronauts do better. Orbiting at one-twenty-six-thousandth the speed of light, they can actually gauge the amount by which their time runs slow, using sensitive clocks—which brings up a seldom discussed puzzle. Though they move faster, astronauts have also traveled away from Earth’s surface into a weaker gravity, which has the opposite effect, speeding their passage of time. Turns out, their high-speed factor prevails. They age less quickly than people on the ground. They’d have to be eight times higher than the International Space Station’s orbit, or two thousand miles above Earth’s surface, before the weaker gravity there exactly balanced their now slower orbital speed to let them age at the same rate as those back home. Still farther away, timepieces on the Moon tick faster than those at mission control in Houston—even if nobody compensated Apollo crews with early Social Security benefits.

These time distortions aren’t subtle, nor are they merely of academic interest. Those GPS satellites simply wouldn’t work if continual compensations weren’t added for various time-warping effects. Since receiving precise time signals from each satellite lies at the very heart of that navigation system, anything that throws off the instruments’ or receivers’ time passage will blow the whole thing.

Are you a truly nerdy, geeky person who cares about such technological or physics details? If so, consider the many wrinkles in how time seems to flow, all introduced by the very technology designed to measure it:

Wrinkle one: Satellites travel at 8,700 miles per hour, slowing their clocks.

Wrinkle two: They’re distant from Earth in a reduced gravitational field, which accelerates their time relative to Earth’s surface.

Wrinkle three: GPS users on the Earth’s surface are located at various distances from Earth’s center (at Denver’s high altitude versus low-altitude Miami, say), producing a variety of time-passage rates.

Wrinkle four: The difference in Earth’s rotation speed at separate ground-based locations produces inconsistencies in their agreement about the passage of time, which is called the Sagnac effect.

Wrinkle five: Time runs slower for all earthly observers (as compared to any future lunar colonists) because of our planet’s 1,040-mph equatorial spin. (The speed decreases the farther one is from the equator.)

Wrinkle six: Satellites’ time passage continually changes because their slightly elliptical orbits make them speed up and slow down, plus they zoom through irregularities in Earth’s gravitational field due to things like our planet’s equatorial bulge.

All told, six separate Einsteinian time distortions affect receivers’ clocks; half of these also distort the satellites’ clocks. They must all be accurately and continuously corrected. Any inconsistencies would ruin the system’s accuracy, big time.

And always remember: We’re not talking about the warping of an actual entity called time. We’re noticing only that events unfold at more leisurely rates, or more hurriedly, than they did before, relative to others. This remains a central point. A hawk flaps its wings slowly, whereas a hummingbird’s wings beat furiously. Sure, we could bring our concepts of time into the discussion, yet we needn’t do so. The event is one thing. How we categorize or measure it is another.

For those who may imagine that such “time warps” are only a mind game, a mere theory, the fact is, Einstein’s time dilation even causes death. When cosmic rays (highly energetic particles striking our atmosphere) collide with molecules in the upper layer of air, they break atoms apart like a cue ball smashing a stack of billiards. The resulting rain of subatomic particles includes some that can be lethal to humans if they strike the wrong bit of genetic material. These muons dash through our bodies constantly, causing some of the spontaneous natural cancers that have always plagued our species. Over 200 of these penetrate each of our bodies every second—more if you live higher up, like in dangerous Denver again. The point is, muons, intermediate in mass between protons and electrons, exist for just 2 microseconds before decaying into harmless by-products. And a few microseconds is not long enough for them to make it all the way to Earth’s surface and into our cells, even though they travel a hefty fraction of the speed of light.

Muons should decay so quickly after being created thirty-five miles up, they ought not be able to reach us. They should never arrive here. They should not cause us any trouble. But they do. What we count as a few microseconds becomes a longer period of time to the muons. Long enough to live on and on. Their time has slowed because of their high speed. To us observing it, the muon’s life has been extended—and ours perhaps shortened. Yet from the particle’s perspective, time passes normally.

There are places in the universe where only a single second of events pass while a million years’ worth of activities simultaneously elapses here on Earth. Yet both feel a normal passage of time.

So observers in different places experience out-of-sync sequences. If the rate of the passage of events depends on factors like the local gravity and one’s speed, how can there be a stable commodity called time?

Exploring this, physicists look to see if time is critical, or even has existence, in their physics equations—or whether what has been spoken of as time is merely the fact of change, long represented by the capital Greek letter delta: ∆. Doing so, they find that Newton’s laws, Einstein’s equations in all his theories, and even those of the quantum theory that came later, are all time symmetrical. Time simply plays no role. There is no forward movement of time. Many in the physical sciences thus declared time to be nonexistent.

As Craig Callender wrote in 2010, in Scientific American²:

The present moment feels special. It is real. However much you may remember the past or anticipate the future, you live in the present. Of course, the moment during which you read that sentence is no longer happening. This one is. In other words, it feels as though time flows, in the sense that the present is constantly updating itself. We have a deep intuition that the future is open until it becomes present and that the past is fixed. As time flows, this structure of fixed past, immediate present and open future gets carried forward in time. This structure is built into our language, thought and behavior. How we live our lives hangs on it.

Yet as natural as this way of thinking is, you will not find it reflected in science. The equations of physics do not tell us which events are occurring right now—they are like a map without the “you are here” symbol. The present moment does not exist in them, and therefore neither does the flow of time. Additionally, Albert Einstein’s theories of relativity suggest not only that there is no single special present but also that all moments are equally real.

Philosophers generally agreed. After all, the past is just a selective memory; your recollections of an event are different from mine. Both memories are simply that—signals from brain cells, neurons firing in the present moment. If the past is an idea that can only occur in the here and now, and the future is also just a concept happening strictly in the present, there seems nothing but now. Always. So is there really a past and a future? Or just a continuum of present moments?

This debate is not new. As we’ve seen, several classical Greek writers believed that the universe is eternal, with no origins at all. Possessing such an infinite past with no beginning made time seem meaningless. Eternity, after all, is fundamentally different from “time without end.” Even as long ago as the fifth century b.c.e., Antiphon the Sophist, in his work On Truth, wrote, “Time is not a reality, but a concept or a measure.”

In the town of Elea, Parmenides seconded this in his poem, On Nature, in a section titled “The Way of Truth,” in which he stated that reality, which he referred to as “what-is,” is one, and that existence is timeless. He called time an illusion.

Soon after, still in the fifth century b.c.e, in that same Greek town of Elea, the famous Zeno created his enduring paradoxes, which in the next chapter will provide critical instruction on how to tell the difference between the conceptual realm of ideas and math versus the actual physical world. (This will resolve that old nagging paradox of the tortoise racing the hare, which has been filed in your brain all these years in a section devoted to “miscellaneous mental torment.”) Zeno will also help show us how neither time nor space are actual physical entities.

In sharp contrast to the carefree Greek musings on eternity, medieval theologians and philosophers tended to see God alone as infinite. To them, His creation, the universe, must therefore indeed have a finite past, a specific moment of birth, and an assumed expiration date. By this reasoning, time is part of the cosmos and thus is itself finite.

Enough philosophizing. Though such debates continue today, they’ve been offered only to illustrate how time’s reality, so assumed by the public, continues to be seriously doubted among people with excessive leisure time who ponder such things. More central for us, it is doubted even in the mainstream of science. And it is the science alone that we will now continue to pursue as we heat up our hunt for a definitive resolution to the time business—our first key to understanding existence, death, and our true relationship with the cosmos.

We must shift to the only place in science where a directionality of time is assumed to be needed: the field of thermodynamics, whose second law involves a process called entropy. This natural inclination to go from order to disorder necessitates an “arrow” or direction to time. If such an arrow exists, then time is a real item after all and will disconcertingly tick away the remaining minutes of your life.

We’d better hurry up and get to the bottom of this. We’ll call on real people who helped clarify what’s going on. This odyssey will lead from Parmenides and Zeno, whose world was very different from ours, to nineteenth-century Europe and a name known to every physics student—the brilliant, fascinating, but ultimately tragic Ludwig Boltzmann.

² http://www.scientificamerican.com/article/is-time-an-illusion/.