"To understand how the Bell works," Anna explained, "you must first understand quantum theory."
Lisa studied the German woman. Her pupils were dilated from the codeine. She was taking too much. Anna's fingers shook with fine tremors. She clutched her reading glasses in both hands, as if they were an anchor. They had retreated to the back of the jet. Gunther still slept under guard in the front.
"I don't think we have time for the full Ph.D. program," Painter said.
"Naturlich. Only three principles need to be understood." Anna let go of her glasses long enough to hold up one finger. "First, we must understand that once matter is broken down to the subatomic level—the world of electrons, protons, and neutrons—then the classical laws of the universe begin to erode. Max Planck discovered that electrons, protons, and neutrons act as both particles and waves. Which seems strange and contradictory. Particles have distinct orbits and paths, while waves are more diffuse, less distinct, lacking any specific coordinates."
"And these subatomic particles act like both?" Lisa asked.
"They have the potential to be either a wave or a particle," Anna said. "Which brings us to our next point. The Heisenberg Uncertainty Principle."
Lisa was already familiar with it and had read further about it back in Anna's laboratory. "Heisenberg basically states that nothing is certain until it is observed," she said. "But I don't understand what that has to do with electrons, protons, and neutrons."
"The best example of Heisenberg's principle is Schrodinger's cat," Anna responded. "Put a cat in a sealed box hooked to a device that may or may not poison the cat at any moment. Purely random odds. Dead or alive. Heisenberg tells us that in that situation, with the box closed, that the cat is potentially both dead and alive. Only once someone opens the box and looks inside does reality choose one state or the other. Dead or alive."
"Sounds more philosophical than scientific," Lisa said.
"Perhaps when you're talking about a cat. But it has been proven true at the subatomic level."
"Proven? How?" Painter asked. He had sat quietly up until now, letting Lisa direct the questioning. She sensed he knew much of this already but wanted Lisa to get all the information she needed.
"In the classic double-slit test," Anna said. "Which brings us to point number three." She picked up two pieces of paper and drew two slits on one and held them up on end, one behind the other.
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"What I'm about to tell you is going to seem strange and against common sense… Suppose this piece of paper were a concrete wall and the slits were two windows. If you took a gun and sprayed bullets at both slits, you'd get a certain pattern on the wall on the far side. Like this."
She took the second piece of paper and punched dots on it.
"Call this Diffraction Pattern A. The way bullets or particles would pass through these slits."
Lisa nodded. "Okay."
"Next, instead of bullets, let's shine a big spotlight on the wall, with light passing through both slits. Because light travels in waves, we would get a different pattern on the far wall."
She shaded a pattern of light and dark bands across a new piece of paper.
"This patterning is caused by the light waves passing through the right and left windows interfering with each other. So let's call this Interference Pattern B…what is caused by waves."
"Got it," Lisa said, not sure where this was going.
Anna held up the two patterns. "Now take an electron gun and shoot a single line of electrons at the double slits. What pattern would you get?"
"Since you're shooting electrons like bullets, I'd guess Diffraction Pattern A." Lisa pointed to the first picture.
"Actually, in laboratory tests you get the second. Interference Pattern B."
Lisa thought about this. "The wave pattern. So then the electrons must be shooting out of the gun—not like bullets—but like light out of a flashlight, traveling in waves and creating Pattern B."
"Correct."
"So electrons move like waves."
"Yes. But only when no one actually witnesses the electrons passing through the slits."
"I don't understand."
"In another experiment, scientists placed a little clicker at one of the slits. It beeped whenever it sensed an electron passing through the slit, measuring or observing the passage of an electron past the detector. What was the pattern on the other side when the device was turned on?"
"It shouldn't change, should it?"
"In the larger world, you're correct. But not at the subatomic world. Once the device was switched on, it immediately changed into Diffraction Pattern A."
"So the simple act of measuring changed the pattern?"
"Just as Heisenberg predicted. Though it may seem impossible, it's true. Verified over and over again. Electrons exist in a constant state of both wave and particle until something measures the electron. That very act of measuring the electron forces it to collapse into one reality or the other."
Lisa tried to picture a subatomic world where everything was held in a constant state of potential. It made no sense.
"If subatomic particles make up atoms," Lisa asked, "and atoms make up the world we know, touch, and feel, where is the line between the phantom world of quantum mechanics and our world of real objects?"
"Again, the only way to collapse potential is to have something measure it. Such measuring tools are constantly present in the environment. It can be one particle bumping into another, a photon of light hitting something. Constantly the environment is measuring the subatomic world, collapsing potential into hard reality. Look at your hands, for example. At the quantum level, the subatomic particles that make up your atoms operate according to fuzzy quantum rules, but expand outward, into the world of billions of atoms that make up your fingernail. Those atoms are bumping, jostling, and interacting—measuring one another—forcing potential into one fixed reality."
"Okay…"
Anna must have heard the skepticism in her voice.
"I know it's bizarre, but I've barely scratched the surface of the fuzzy world of quantum theory. I'm skipping over such concepts as nonlocality, time tunneling, and multiple universes."
Painter nodded. "Gets pretty weird out there."
"But all you need to understand are those three points," Anna said, ticking them off on her fingers. "Subatomic particles exist in a quantum state of potential. It takes a measuring tool to collapse that potential. And it is the environment that constantly performs those measurements to fix our reality."