Space Chronicles: Facing the Ultimate Frontier (34 page)

C
onsider what it’s like to be a spacecraft living and working hundreds of millions of miles from the Sun. First of all, your sunny side warms up while the unheated hardware on your shady side can plunge to –455° Fahrenheit, the background temperature of outer space. Next, you’re constructed of many different kinds of materials and have multiple appendages, all of which have different thermal properties and thus absorb, conduct, emit, and scatter heat differently, both within your various cavities and outside to space. In addition, your parts like to operate at very different temperatures: your cryogenic science instruments do fine in the frigidity of outer space, but your cameras favor room temperature, and your rocket thrusters, when fired, register 2,000° F. Not only that, every piece of your hardware sits within ten feet of all your other pieces of hardware.

The task facing Kinsella and his team of engineers was to assess and quantify the directional thermal influence of every feature aboard Pioneer 10. To do that, they created a computer model representing the spacecraft surrounded by a spherical envelope. Then they subdivided that surface into 2,600 zones, enabling them to track the flow of heat from every spot in the spacecraft to and through every spot in the surrounding sphere. To strengthen their case, they also hunted through all available project documents and data files, many of which hail from the days when computers relied on punch cards for data entry and stored data on nine-track tape. (Without emergency funds from the Planetary Society, by the way, those irreplaceable archives would shortly have ended up in a Dumpster.)

For the simulated world of the team’s computer model, the spacecraft was placed at a test distance from the Sun (25 AU) and at a specific angle to the Sun, and all the parts were presumed to be working as they were supposed to. Kinsella and his crew determined that, indeed, the uneven thermal emission from the spacecraft’s exterior surfaces does create an anomaly—and that it is indeed a continuous, sunward change in velocity.

But how much of the Pioneer anomaly can be blamed on this effect? Certainly some. Perhaps most. Possibly all.

S
o what about any remaining unexplained portion of the anomaly? Do we sweep it under the cosmic rug in hopes that additional Kinsellan analysis will eventually resolve the entire anomaly? Or do we carefully reconsider the accuracy and inclusiveness of Newton’s laws of gravity, as a few zealous physicists have been doing for a couple of decades?

Pre-Pioneers, Newtonian gravity had never been measured—and was therefore never confirmed—with great precision over great distances. In fact, Slava Turyshev, an expert in Einstein’s general relativity, regards the Pioneers as (unintentionally) the largest-ever gravitational experiment to confirm whether Newtonian gravity is fully valid in the outer solar system. That experiment, he contends, shows it might not be. In addition, as any physicist can demonstrate, beyond 15 AU the effects of Einsteinian gravity are negligible.

In early 2009, for the benefit of visitors to the Planetary Society’s website, Turyshev and his colleague Viktor Toth eloquently explained why they’ve kept plugging away at the Pioneer anomaly. Their explanation, titled “Finding a needle in the haystack or proving that there may be none,” is worth quoting at length:

In the short run, knowing the gravitational constant to one more decimal digit of precision or placing even tighter limits on any deviation from Einstein’s gravitational theory may seem like painfully nit-picking detail. Yet one must not lose sight of the “big picture.” When researchers were measuring the properties of electricity with ever more refined instruments over two hundred years ago, they did not envision continent-spanning power grids, an information economy, or tiny electrical signals reaching us from the unfathomable depths of the outer solar system, sent by man-made machines. They just performed meticulous experiments laying down the laws connecting electricity to magnetism or the electromotive force to chemical reactions. Yet their work paved the way to our modern society.

Similarly, we cannot envision today what research into gravitational science will bring tomorrow. Perhaps one day humankind will harness gravity. Perhaps one day a trip across the solar system using a yet-to-be-devised gravity engine may not seem a bigger deal than crossing an ocean in a jetliner today. Perhaps one day human beings will travel to the stars in spacecraft that no longer need rockets. Who knows? But one thing we know for sure: none of that will happen unless we do a meticulous job today. Our work, whether it proves the existence of gravity beyond Einstein or just improves the navigation of spacecraft in deep space by accounting for a small thermal recoil force with precision, lays down the foundations that may, one day, lead to such dreams.

For the time being, though, two forces seem to be at play in deep space: Newton’s laws of gravity and the mysterious Pioneer anomaly. Until the anomaly is thoroughly accounted for by misbehaving hardware, and can therefore be eliminated from consideration, Newton’s laws will remain unconfirmed. And there just might be a rug somewhere in the cosmos with a new law of physics under it, waiting to be uncovered.

• • •
CHAPTER THIRTY-SIX

WHAT NASA MEANS TO AMERICA’S FUTURE
^*

I
wish I had a nickel for every time someone said, “Why are we spending money up there when we have problems down here?” The first and simplest answer to that concern is that one day there’ll be a killer asteroid headed straight for us, which means not all your problems are Earth-based. At some point, you’ve also got to look up.

Under President Barack Obama’s space plan, NASA will be promoting commercial access to low Earth orbit. The National Aeronautics and Space Act of 1958 makes NASA responsible for advancing the space frontier. And since low Earth orbit is no longer a space frontier, NASA must move to the next step. The current plan says we’re not going to the Moon anymore and recommends we go to Mars one day—I don’t know when.

I’m worried by this scenario. Without an actual plan to go somewhere beyond low Earth orbit, we’ve got nothing to shape the career dreams of young America. As best as I can judge, NASA is like a force of nature unto itself, capable of stimulating the formation of scientists, engineers, mathematicians, and technologists—the STEM research fields. You nurture these people for the sake of society, and they become the ones who make tomorrow happen.

The strength of economies in the twenty-first century will derive from the investments made in science and technology. This is something we’ve witnessed since the dawn of the Industrial Revolution: the nations that have embraced those investments are the nations that have led the world.

America is fading right now. Nobody’s dreaming about tomorrow anymore. NASA knows how to dream about tomorrow—if the funding can accommodate it, if the funding can empower it, if the funding can enable it. Sure, you need good teachers. But the teachers come and go, because kids go on to the next grade and then the grade after that. Teachers can help light a flame, but we need something to keep the flame fanned. And that’s the effect of NASA on who and what we are as a nation, what we have been as a nation, and perhaps for a while took for granted as a nation. Today the most powerful particle accelerator in the world is hundreds of feet underground at the border between France and Switzerland. The world’s fastest train is made by Germans and is running in China. Meanwhile, here in America I see our infrastructure collapsing and no one dreaming about tomorrow.

Everybody thinks they can put a Band-Aid on this or that problem. Meanwhile, the agency with the most power to shape the dreams of a nation is currently underfunded to do what it must be doing—which is to make those dreams come true. And doing it for half a penny on a dollar.

How much would
you
pay for the universe?

EPILOGUE

The Cosmic Perspective
*

Of all the sciences cultivated by mankind, Astronomy is acknowledged to be, and undoubtedly is, the most sublime, the most interesting, and the most useful. For, by knowledge derived from this science, not only the bulk of the Earth is discovered . . . ; but our very faculties are enlarged with the grandeur of the ideas it conveys, our minds exalted above [their] low contracted prejudices.

—
J
AMES
F
ERGUSON,
Astronomy Explained Upon Sir Isaac Newton’s Principles, And Made Easy To Those Who Have Not Studied Mathematics
(1757)

L
ong before anyone knew that the universe had a beginning, before we knew that the nearest large galaxy lies more than two million light-years from Earth, before we knew how stars work or whether atoms exist, James Ferguson’s enthusiastic introduction to his favorite science rang true. Yet his words, apart from their eighteenth-century flourish, could have been written yesterday.

But who gets to think that way? Who gets to celebrate this cosmic view of life? Not the migrant farmworker. Not the sweatshop worker. Certainly not the homeless person rummaging through the trash for food. You need the luxury of time not spent on mere survival. You need to live in a nation whose government values the search to understand humanity’s place in the universe. You need a society in which intellectual pursuit can take you to the frontiers of discovery, and in which news of your discoveries can be routinely disseminated. By those measures, most citizens of industrialized nations do quite well.

Yet the cosmic view comes with a hidden cost. When I travel thousands of miles to spend a few moments in the fast-moving shadow of the Moon during a total solar eclipse, sometimes I lose sight of Earth.

When I pause and reflect on our expanding universe, with its galaxies hurtling away from one another, embedded within the ever-stretching, four-dimensional fabric of space and time, sometimes I forget that uncounted people walk this Earth without food or shelter, and that children are disproportionately represented among them.

When I pore over the data that establish the mysterious presence of dark matter and dark energy throughout the universe, sometimes I forget that every day—every twenty-four-hour rotation of Earth—people kill and get killed in the name of someone else’s conception of God, and that some people who do not kill in the name of God kill in the name of their nation’s needs or wants.

When I track the orbits of asteroids, comets, and planets, each one a pirouetting dancer in a cosmic ballet choreographed by the forces of gravity, sometimes I forget that too many people act in wanton disregard for the delicate interplay of Earth’s atmosphere, oceans, and land, with consequences that our children and our children’s children will witness and pay for with their health and well-being.

And sometimes I forget that powerful people rarely do all they can to help those who cannot help themselves.

I occasionally forget those things because, however big the world is—in our hearts, our minds, and our outsize atlases—the universe is even bigger. A depressing thought to some, but a liberating thought to me.

Consider an adult who tends to the traumas of a child: a broken toy, a scraped knee, a schoolyard bully. Adults know that kids have no clue what constitutes a genuine problem, because inexperience greatly limits their childhood perspective.

As grown-ups, dare we admit to ourselves that we, too, have a collective immaturity of view? Dare we admit that our thoughts and behaviors spring from a belief that the world revolves around us? Apparently not. Yet the evidence abounds. Part the curtains of society’s racial, ethnic, religious, national, and cultural conflicts, and you find the human ego turning the knobs and pulling the levers.

Now imagine a world in which everyone, but especially people with power and influence, holds an expanded view of our place in the cosmos. With that perspective, our problems would shrink—or never arise at all—and we could celebrate our earthly differences while shunning the behavior of our predecessors who slaughtered each other because of them.

B
ack in February 2000, the newly rebuilt Hayden Planetarium featured a space show called “Passport to the Universe,” written by Ann Druyan and Steven Soter (collaborators with Carl Sagan on the original
Cosmos
TV series). The show took visitors on a virtual zoom from New York City to the deepest regions of space. En route the audience saw Earth, then the solar system, then the Milky Way galaxy’s hundreds of billions of stars shrink to barely visible dots on the planetarium’s dome.

Within a month of opening day, I received a letter from an Ivy League professor of psychology whose expertise was things that make people feel insignificant. I never knew one could specialize in such a field. He wanted to administer a before-and-after questionnaire to visitors, assessing the depth of their depression after viewing “Passport to the Universe.” The show, he wrote, elicited the most dramatic feelings of smallness he had ever experienced.

How could that be? Every time I see the space show (and others we’ve produced), I feel alive and spirited and connected. I also feel large, knowing that the goings-on within the three-pound human brain are what enabled us to figure out our place.

Allow me to suggest that it’s the professor, not I, who has misread nature. His ego was too big to begin with, inflated by delusions of significance and fed by cultural assumptions that human beings are more important than everything else.

In all fairness to the fellow, powerful forces in society leave most of us susceptible. As was I . . . until the day I learned in biology class that more bacteria live and work in one centimeter of my colon than the number of people who have ever existed in the world. That kind of information makes you think twice about who—or what—is actually in charge.

From that day on, I began to think of people not as the masters of space and time but as participants in a great cosmic chain of being, with a direct genetic link across species both living and extinct, extending back nearly four billion years to the earliest single-celled organisms on Earth.

I
know what you’re thinking: we’re smarter than bacteria.

No doubt about it, we’re smarter than every other living creature that ever walked, crawled, or slithered on Earth. But how smart is that? We cook our food. We compose poetry and music. We do art and science. We’re good at math. Even if you’re bad at math, you’re probably much better at it than the smartest chimpanzee, whose genetic identity varies in only trifling ways from ours. Try as they might, primatologists will never get a chimpanzee to learn the multiplication table or do long division.

If small genetic differences between us and our fellow apes account for our vast difference in intelligence, maybe that difference in intelligence is not so vast after all.

Imagine a life-form whose brainpower is to ours as ours is to a chimpanzee’s. To such a species, our highest mental achievements would be trivial. Their toddlers, instead of learning their ABCs on
Sesame Street,
would learn multivariable calculus on
Boolean Boulevard.
Our most complex theorems, our deepest philosophies, the cherished works of our most creative artists, would be projects their schoolkids bring home for Mom and Dad to display on the refrigerator door. These creatures would study Stephen Hawking (who occupies the same endowed professorship once held by Newton at the University of Cambridge) because he’s slightly more clever than other humans, owing to his ability to do theoretical astrophysics and other rudimentary calculations in his head.

If a huge genetic gap separated us from our closest relative in the animal kingdom, we could justifiably celebrate our brilliance. We might be entitled to walk around thinking we’re distant and distinct from our fellow creatures. But no such gap exists. Instead, we are one with the rest of nature, fitting neither above nor below, but within.

N
eed more ego softeners? Simple comparisons of quantity, size, and scale do the job well.

Take water. It’s simple, common, and vital. There are more molecules of water in an eight-ounce cup of the stuff than there are cups of water in all the world’s oceans. Every cup that passes through a single person and eventually rejoins the world’s water supply holds enough molecules to mix fifteen hundred of them into every other cup of water in the world. No way around it: some of the water you just drank passed through the kidneys of Socrates, Genghis Khan, and Joan of Arc.

How about air? Also vital. A single breathful draws in more air molecules than there are breathfuls of air in Earth’s entire atmosphere. That means some of the air you just breathed passed through the lungs of Napoleon, Beethoven, Lincoln, and Billy the Kid.

Time to get cosmic. There are more stars in the universe than grains of sand on any beach, more stars than seconds have passed since Earth formed, more stars than words and sounds ever uttered by all the humans who ever lived.

Want a sweeping view of the past? Our unfolding cosmic perspective takes you there. Light takes time to reach Earth’s observatories from the depths of space, and so you see objects and phenomena not as they are but as they once were. That means the universe acts like a giant time machine: the farther away you look, the further back in time you see—back almost to the beginning of time itself. Within that horizon of reckoning, cosmic evolution unfolds continuously, in full view.

Want to know what we’re made of? Again, the cosmic perspective offers a bigger answer than you might expect. The chemical elements of the universe are forged in the fires of high-mass stars that end their lives in stupendous explosions, enriching their host galaxies with the chemical arsenal of life as we know it. The result? The four most common chemically active elements in the universe—hydrogen, oxygen, carbon, and nitrogen—are the four most common elements of life on Earth. We are not simply in the universe. The universe is in us.

Y
es, we are stardust. But we may not be of this Earth. Several separate lines of research, when considered together, have forced investigators to reassess who we think we are and where we think we came from.

First, computer simulations show that when a large asteroid strikes a planet, the surrounding areas can recoil from the impact energy, catapulting rocks into space. From there, they can travel to—and land on—other planetary surfaces. Second, microorganisms can be hardy. Some survive the extremes of temperature, pressure, and radiation inherent in space travel. If the rocky flotsam from an impact hails from a planet with life, microscopic fauna could have stowed away in the rocks’ nooks and crannies. Third, recent evidence suggests that shortly after the formation of our solar system, Mars was wet, and perhaps fertile, even before Earth was.

Those findings mean it’s conceivable that life began on Mars and later seeded life on Earth, a process known as panspermia. So all earthlings might—just might—be descendants of Martians.

Again and again across the centuries, cosmic discoveries have demoted our self-image. Earth was once assumed to be astronomically unique, until astronomers learned that Earth is just another planet orbiting the Sun. Then we presumed the Sun was unique, until we learned that the countless stars of the night sky are suns themselves. Then we presumed our galaxy, the Milky Way, was the entire known universe, until we established that the countless fuzzy things in the sky are other galaxies, dotting the landscape of our known universe.

Today, how easy it is to presume that one universe is all there is. Yet emerging theories of modern cosmology, as well as the continually reaffirmed improbability that anything is unique, require that we remain open to the latest assault on our plea for distinctiveness: multiple universes, otherwise known as the multiverse, in which ours is just one of countless bubbles bursting forth from the fabric of the cosmos.

T
he cosmic perspective flows from fundamental knowledge. But it’s more than just what you know. It’s also about having the wisdom and insight to apply that knowledge to assessing our place in the universe. And its attributes are clear:

The cosmic perspective comes from the frontiers of science, yet it is not solely the provenance of the scientist. It belongs to everyone.

The cosmic perspective is humble.

The cosmic perspective is spiritual—even redemptive—but not religious.

The cosmic perspective enables us to grasp, in the same thought, the large and the small.

The cosmic perspective opens our minds to extraordinary ideas but does not leave them so open that our brains spill out, making us susceptible to believing anything we’re told.

The cosmic perspective opens our eyes to the universe, not as a benevolent cradle designed to nurture life but as a cold, lonely, hazardous place.

The cosmic perspective shows Earth to be a mote, but a precious mote and, for the moment, the only home we have.

The cosmic perspective finds beauty in the images of planets, moons, stars, and nebulae but also celebrates the laws of physics that shape them.