Trespassing on Einstein's Lawn (5 page)

We sat down on the sidewalk in front of the house.

“A self-excited circuit …,” I mumbled.

My father nodded. “The boundary of a boundary is zero.… ”

“Who is he, Yoda?” I asked. “The man speaks in riddles. What do you think it means?”

My father smiled. “I have no freakin' idea.”

So there we were, in Princeton, New Jersey, in a vast and expanding universe, exhilarated, trespassing, half real, realizing that what once had been a hobby had now become a mission.

We sat for a few moments steeped in the heavy silence. Then a car pulled up, and we ran.

When I returned to New York, I had an epiphany.

I was staring up at the Science and Ultimate Reality press pass that hung on the wall above my computer as a souvenir of the conference and, with “
Manhattan
Magazine” printed proudly beneath my name, as a kind of inside joke. The badge contained an image of a pixilated sphere with a 0 or a 1 marked in each pixel. I was pretty sure it was one of Wheeler's drawings—but what did it mean? I quickly sketched it in my notebook with a reminder to myself to find out.

It was amazing how powerful that thing was. A piece of laminated paper on a string could give you access to ultimate reality's inner circle? It was like the golden ticket to cosmology's chocolate factory—find one and you win the chance to attend every lecture, talk with every physicist, even enjoy the lunches and banquets.

If we wanted to crash the ultimate reality party in the hopes of finding some answers, a press pass was clearly the way to do it. Still, I was pretty sure that my little scam wasn't going to cut it for long. Eventually someone was bound to look up
Manhattan
magazine and realize that it had nothing whatsoever to do with physics and that the magazine's ontological status was … well, anyone peering inside that box was going to find a dead cat.

If only there was some other way to get press passes.

A cartoon lightbulb lit up overhead.

I called my father. “I'm going to be a journalist.”

“Okay …”

“Think about it! If we want to figure out the nature of reality, we need access to the best physicists around, the cutting-edge data, the meetings, the journals, everything. And if you're press, it's all yours! When we have a question about cosmology, we won't have to dig through twenty books to find the answer; we'll just ask a cosmologist! It's the perfect alibi!”

“That's a great idea,” he said. “Maybe you could get some kind of internship. Or do you have to get a degree first?”

“No, no,” I said, “you're missing my point. I'm going to become a journalist
today.
”

“Sorry, what?”

“Yeah, I'm going to call
Scientific American
and ask if I can write something for them about the symposium. Then we'll be golden.”

“Listen,” he said, “I don't want to burst your bubble, and I think you could make a great journalist someday, but you can't just call
Scientific American.
”

Our golden tickets to the ultimate reality party
W. Gefter

“Oh, yeah?” I said. “Watch me.”

I knew I sounded a little nuts. After all, I hadn't gone to journalism school. Hell, I had never taken a physics class. But who cares, I thought. I would just have to learn on the job. Besides, I didn't need a degree and an internship and job experience—that would be like going to culinary school just to open a restaurant as a mob front. I wasn't trying to win a Pulitzer; I was just trying to scam some press passes.

I hung up the phone and dialed the number for
Scientific American
's news editor. Voicemail. When I heard the beep, I cleared my throat and tried my best to muster up a voice that would sound like that of a professional colleague, not a twenty-one-year-old girl. “Oh, hey, Phil, this is Amanda Gefter over here at
Manhattan
magazine, I'm just calling because I attended yesterday's symposium down at Princeton in honor of John Wheeler, and I wanted to check in with you to see if you need any coverage of it. We don't really run science stories here at
Manhattan
, but physics is sort of a side hobby of mine. Anyway, there was some good stuff, so feel free to give me a call.”

I left my number and hung up the phone. If we were going to do this, we were going to do it right, and that meant starting at the top.

Phil from
Scientific American
called back the next day. “We had one of our editors at the symposium,” he told me, “so we've pretty much got it covered. But if you come up with some interesting angle, email me.”

Interesting angle? I could do that. I sat down and looked over my notes from the meeting. Trying to pitch an article about any one talk wasn't going to work—anyone who had been at the symposium could do that. Of course Wheeler's strange message—
the universe is a self-excited circuit
,
the boundary of a boundary is zero
—was an angle, but I had no idea what the hell it meant. I'd have to find something else for now.

That's when I noticed a theme. Throughout the symposium, there had been a giant elephant in the room: the anthropic principle.

The anthropic principle invoked our own existence to account for certain features of the universe—its size, its physical constants, the existence of stars and galaxies. Had those features been even slightly
different, we wouldn't be here to wonder about them. At its worst, the anthropic principle was an empty tautology: we exist, therefore the universe is the kind of place that allows us to exist. At its best, it offered a way for physicists to explain why many cosmic features have such extraordinarily unlikely values—unlikely, but perfectly ripe for life.

I sat down at my computer and composed an email to Phil suggesting a small news item entitled, “Physicists Can't Avoid the
A
-Word.”
At the Science and Ultimate Reality conference
, I wrote,
physicist Andy Albrecht began his presentation by assuring the audience
,
“I'm not going to use the
A-
word.”

Anthropic
had become a four-letter word because it veered uncomfortably close to religion, I explained—as if the universe, somehow, were built just for us. That is, unless our universe isn't the only one. It's like the Earth. Our homey planet is positioned at the perfect distance from the Sun to host liquid water; any closer and the water would turn to gas, any farther and it would freeze. If the Earth were the only planet—a lone rock adrift in the solar system—its water-bearing position would seem awfully miraculous. But with seven other planets wandering around out there, it's hardly a miracle that we find ourselves on the one that's suitable for life—we're here because it's the only place we can be. The same kind of anthropic selection bias can explain the life-bearing features of the universe, all for the low, low price of a few trillion extra universes. Not that it's the kind of explanation anyone wants. Physicists want to explain the universe through logical and mathematical necessity. They want the world to be the way it is because that's the
only
way a world could be. But according to the anthropic principle, anything goes.

Still, everyone's efforts to avoid the
A
-word seemed a little odd, given the occasion.
After all
, I wrote,
it was Wheeler who famously described the universe as “participatory,”
and once asked
,
“On what else can a comprehensible universe be built but the demand for comprehensibility?”
Wheeler didn't believe that the universe was designed for us, nor that ours was a small island in a vast multiverse. He believed that the universe was right for observers because, somehow, observers
create
the universe.

I noted that the $10,000 prize for the Young Researchers Competition in Physics was awarded at the conference to Fotini Markopoulou, a loop quantum gravity researcher at the Perimeter Institute for Theoretical Physics in Canada. In her winning paper she argued that cosmology must describe the universe as seen by observers who are stuck inside it.
In the end
,
it seems
,
the more we pursue the deepest mysteries of the cosmos
, I wrote,
the closer we come to ourselves.

I clicked “Send.”

Phil emailed back right away. He explained that
Scientific American
had a similar piece in the works about the anthropic principle, but they were interested in Fotini Markopoulou. “What do you know about loop quantum gravity?” he asked.

What did I know about loop quantum gravity? Approximately … nothing. I called my father and read him the email.

“Oh, well,” he said. “You tried.”

“Tried?” I said. “This isn't over. This is our one shot!”

“Okay, but—”

“We have one night to learn loop quantum gravity.”

“You're joking,” he said. “Why one night?”

“If I don't write back tomorrow, it will seem like I took the time to look this stuff up. It has to look like I know it off the top of my head. We don't have much time—start reading and call me back in a few hours!”

I absorbed what I was reading as best I could. Loop quantum gravity was an attempt to unify general relativity and quantum mechanics—the seemingly correct yet mutually exclusive pillars of modern physics. Such unification is the key to the origin of the universe, that placeholder on the map where nothing turns into something, where the H-state becomes the world.
Need quantum gravity to understand singularities
, I had written in my notebook.
To understand nothing.
Loop quantum gravity's approach was to zoom in on space, peering down to nature's smallest scale to see what dragons lurk there.

That nature even
has
a smallest scale was pretty hard to grasp. I couldn't wrap my mind around the notion that if I were to zoom in on some modest stretch of space, magnifying it and peering into increasingly smaller depths, I would eventually reach a place further from me in scale than the entire observable universe—and yet, somehow, right here on the tip of my finger. A universe larger than the universe, sitting in the palm of my hand. Only you can't keep zooming forever. At a millionth of a billionth of a billionth of a billionth of a centimeter, you hit the bottom of reality. Sorry, folks, you've reached the end—the teeny-tiny edge of the universe.

Space ends there, at the so-called Planck scale, because that's where quantum mechanics and general relativity join forces to bend spacetime until it breaks. The sheer density of gravity produces a sea of black holes, which Wheeler dubbed “spacetime foam.”

It was a counterintuitive notion—usually when you're dealing with small things, gravity is negligible. Gravity acts on mass, and you need a lot of it before you notice its pull. Even at the human scale, gravity is pretty insignificant. A refrigerator magnet can overpower the gravitational force of the entire planet just to lift a paper clip. At the scale of protons and electrons, gravity barely exists at all.

But keep zooming in and, strangely, things start to turn around. The laws of quantum mechanics contain a loophole that allows large fluctuations of energy to burst forth from the vacuum, provided they don't stick around too long. At increasingly shorter time scales, energy blinks in and out of existence in the form of fleeting, or “virtual,” particles. The more localized the virtual particle, the greater its momentum, and the greater its momentum, the larger its energy. Thanks to E = mc
²
, more energy means more mass. So as you look at smaller and smaller distances, virtual particles grow increasingly massive until, at the Planck scale, gravity grows as powerful as the other forces. An energy in its own right, gravity's crescendo generates a runaway feedback disaster of the same variety that can collapse a 10
³²
-pound star into a black hole. At distances smaller than the Planck scale, gravitational feedback turns pathological. The universe turns on itself, cannibalizes. The fabric of reality bursts at the seams. Before melds into after, here conquers there, distance and duration give way to confusion and chaos,
space and time dissolve and disappear. Equations sizzle and spark, mathematics falls apart into nothingness. In short, everything goes to hell. It's the end of the world.

Loop quantum gravity is a model of space at the Planck scale, just before gravity rips it to pieces. Lee Smolin, another Perimeter Institute physicist and a founder of the theory, had realized that the situation would stabilize if space, like matter, has a kind of atomic structure. That way, when you zoom in on a region of space—smaller, smaller, smaller still—you eventually hit a roadblock: a chunk of space that can't be further divided, a spatial “atom” that's as small as small gets. As long as space's atoms are no smaller than the Planck scale, Smolin said, gravity would remain in check. Its energy could only grow so large; its destruction could only wreak so much havoc.