The Living Dead 2 (The Living Dead, #2)(170)

The most unsettling news came from an old and distinguished physicist, a Nobel laureate, who told me that certain of the fundamental physical constants seemed to be slowly and continuously changing. He had been trying to convey the urgent importance of this to the government but as I discovered when I tried to use my contacts to bring his findings to the attention of ministers and members of parliament and civil servants, the government was too busy dealing with the invasion and the consequences of the invasion.

There was an old and hopeful lie that an alien invasion would cause the nations of Earth to set aside their differences and unite against the common enemy. It didn’t happen. Instead, global paranoia and suspicion ratcheted up daily. The zombies were archetypal invaders from within. Hatreds and prejudices that once had been cloaked in diplomatic evasions were now nakedly expressed. Several countries used the invasion as an excuse to attack troublesome minorities or to accuse old enemies of complicity with the zombies. There were genocidal massacres and brush fire wars across the globe. Iran attacked Iraq and Israel with nuclear weapons and what was left of Israel wiped out the capital cities of its neighbours. India attacked Pakistan. China and Russia fought along their long border. The United States invaded Cuba and Venezuela, tried to close its borders with Canada and Mexico, and took sides with China against Russia. And so on, and so on. The zombies didn’t have to do anything to destroy us. We were tearing ourselves apart. We grew weaker as we fought each other and the zombies grew stronger by default.

In Britain, everyone under thirty was called up for service in the armed forces. And then everyone under forty was called up too. Three years after my first encounter, I found myself in a troop ship at the tail end of a convoy wallowing through the Bay of Biscay towards the Mediterranean. Huge columns of zombies were straggling out of the Sahara Desert. We were supposed to stop them. Slaughter them. But as we approached the Straits of Gibraltar, someone, it was never clear who, dropped a string of nuclear bombs on zombies massing in Algeria, Tunisia, Libya, and Egypt. On our ships, we saw the flashes of the bombs light the horizon. An hour later we were attacked by the remnants of the Libyan and Egyptian air forces. Half our fleet were sunk; the rest limped home. Britain’s government was still intact, more or less, but everyone was in the armed forces now. Defending ourselves from the zombies and from waves of increasingly desperate refugees from the continent. There was a year without summer. Snow in July. Crops failed and despite rationing millions died of starvation and cold. There were biblical plagues of insects and all the old sicknesses came back.

And still the zombies kept appearing.

They looked entirely human now, but it was easy to tell what they were because they weren’t starving, or haunted, or mad.

We kept killing them and they kept coming.

They took our cities from us and we fled into the countryside and regrouped and they came after us and we broke into smaller groups and still they came after us.

We tore ourselves apart trying to destroy them. Yet we still didn’t understand them. We didn’t know where they were coming from, what they were, what they wanted. We grew weaker as they grew stronger.

Do you understand me? I think that you do. Your pulse rate and pupil dilation and skin conductivity all show peaks at the key points of my story. That’s good. That means you might be human.

Listen:

Let me tell you what the distinguished old physicist told me. Let me tell you about the observer effect and Boltzmann brains.

In the nineteenth century, the Austrian physicist Ludwig Boltzmann developed the idea that the universe could have arisen from a random thermal fluctuation. Like a flame popping into existence. An explosion from nowhere. Much later, other physicists suggested that similar random fluctuations could give rise to anything imaginable, including conscious entities in any shape or form: Boltzmann brains. It was one of those contra-intuitive and mostly theoretical ideas that helped cosmologists shape their models of the universe, and how we fit into it. It helped to explain why the universe was hospitable to the inhabitants of an undistinguished planet of an average star in a not very special galaxy in a group of a million such, and that group of galaxies one of millions more. We are typical. Ordinary. And because we are ordinary, our universe is ordinary too, because there is no objective reality beyond that which we observe. Because, according to quantum entanglement, pairs of particles share information about each other’s quantum states even when distance and timing means that no signal can pass between them. Because observation is not passive. Because our measurements influence the fundamental laws of the universe. They create reality.

But suppose other observers outnumbered us? What would happen then?

The probability of even one Boltzmann brain appearing in the fourteen billion years of the universe’s history is vanishingly small. But perhaps something changed the local quantum field and made it more hospitable to them. Perhaps the density of our own consciousness attracted them, as the mass of a star changes the gravitational field and attracts passing comets. Or perhaps the inhabitants of another universe are interfering with our universe. Perhaps the zombies are their avatars: Boltzmann brains that pop out of the energy field and change our universe to suit their masters simply because they think differently and see things differently.

This was what the old physicist told me, in the long ago. He had evidence, too. Simple experiments that measured slow and continuous changes in the position of the absorption lines of calcium and helium and hydrogen in the sun’s spectrum, in standards of mass and distance, and in the speed of light. He believed that the fundamental fabric of the universe was being altered by the presence of the zombies, and that those changes were reaching back into the past and forward into the future, just as a pebble dropped into a pond will send ripples spreading out to either side. Every time he checked the historical records of the positions of those absorption lines, they agreed with his contemporaneous measurements, even though those measurements were continuously changing. We are no longer what we once were, but we are not aware of having changed because our memories have been changed too.