The farther we peer into space, the more we realize that the nature of the universe cannot be understood fully by inspecting spiral galaxies or watching distant supernovas. It lies deeper. It involves our very selves.
This insight snapped into focus one day while one of us (Lanza) was walking through the woods. Looking up, he saw a huge golden orb web spider tethered to the overhead boughs. There the creature sat on a single thread, reaching out across its web to detect the vibrations of a trapped insect struggling to escape. The spider surveyed its universe, but everything beyond that gossamer pinwheel was incomprehensible. The human observer seemed as far-off to the spider as telescopic objects seem to us. Yet there was something kindred: We humans, too, lie at the heart of a great web of space and time whose threads are connected according to laws that dwell in our minds.
Is the web possible without the spider? Are space and time physical objects that would continue to exist even if living creatures were removed from the scene?
Figuring out the nature of the real world has obsessed scientists and philosophers for millennia. Three hundred years ago, the Irish empiricist George Berkeley contributed a particularly prescient observation:
The only thing we can perceive are our perceptions. In other words, consciousness is the matrix upon which the cosmos is apprehended. Color, sound, temperature, and the like exist only as perceptions in our head, not as absolute essences. In the broadest sense, we cannot be sure of an outside universe at all.
For centuries, scientists regarded Berkeley’s argument as a philosophical sideshow and continued to build physical models based on the assumption of a separate universe “out there” into which we have each individually arrived.
These models presume the existence of one essential reality that prevails with us or without us. Yet since the 1920s, quantum physics experiments have routinely shown the opposite: Results do depend on whether anyone is observing. This is perhaps most vividly illustrated by the famous two-slit experiment.
When someone watches a subatomic particle or a bit of light pass through the slits, the particle behaves like a bullet, passing through one hole or the other. But if no one observes the particle, it exhibits the behavior of a wave that can inhabit all possibilities—including somehow passing through both holes at the same time.
Some of the greatest physicists have described these results as so confounding they are impossible to comprehend fully, beyond the reach of metaphor, visualization, and language itself. But there is another interpretation that makes them sensible. Instead of assuming a reality that predates life and even creates it, we propose a biocentric picture of reality. From this point of view, life—particularly consciousness—creates the universe, and the universe could not exist without us.
Messing with the Light
Quantum mechanics is the physicist’s most accurate model for describing the world of the atom. But it also makes some of the most persuasive arguments that conscious perception is integral to the workings of the universe. Quantum theory tells us that an unobserved small object (for instance, an electron or a photon—a particle of light) exists only in a blurry, unpredictable state, with no well-defined location or motion until the moment it is observed.
This is Werner Heisenberg’s famous uncertainty principle. Physicists describe the phantom, not-yet-manifest condition as a wave function, a mathematical expression used to find the probability that a particle will appear in any given place. When a property of an electron suddenly switches from possibility to reality, some physicists say its wave function has collapsed.
What accomplishes this collapse? Messing with it. Hitting it with a bit of light in order to take its picture. Just looking at it does the job. Experiments suggest that mere knowledge in the experimenter’s mind is sufficient to collapse a wave function and convert possibility to reality. When particles are created as a pair—for instance, two electrons in a single atom that move or spin together—physicists call them entangled. Due to their intimate connection, entangled particles share a wave function.
When we measure one particle and thus collapse its wave function, the other particle’s wave function instantaneously collapses too. If one photon is observed to have a vertical polarization (its waves all moving in one plane), the act of observation causes the other to instantly go from being an indefinite probability wave to an actual photon with the opposite, horizontal polarity—even if the two photons have since moved far from each other.
In 1997 University of Geneva physicist Nicolas Gisin sent two entangled photons zooming along optical fibers until they were seven miles apart. One photon then hit a two-way mirror where it had a choice: either bounce off or go through. Detectors recorded what it randomly did. But whatever action it took, its entangled twin always performed the complementary action.
The communication between the two happened at least 10,000 times faster than the speed of light. It seems that quantum news travels instantaneously, limited by no external constraints—not even the speed of light. Since then, other researchers have duplicated and refined Gisin’s work. Today no one questions the immediate nature of this connectedness between bits of light or matter, or even entire clusters of atoms.
Before these experiments most physicists believed in an objective, independent universe. They still clung to the assumption that physical states exist in some absolute sense before they are measured.
All of this is now gone for keeps.
Wrestling with Goldilocks
The strangeness of quantum reality is far from the only argument against the old model of reality. There is also the matter of the fine-tuning of the cosmos. Many fundamental traits, forces, and physical constants—like the charge of the electron or the strength of gravity—make it appear as if everything about the physical state of the universe were tailor-made for life. Some researchers call this revelation the Goldilocks principle, because the cosmos is not “too this” or “too that” but rather “just right” for life.