One of the most puzzling aspects of quantum mechanics is that tiny particles don't seem to choose a state until an observer measures it. All the vague possibilities of what could happen are converted into a concrete outcome by measurement. The mathematics of quantum mechanics gives rules for how that process works, but they don't explain what that means in practical terms.

One idea is that consciousness, an awareness of our own selves and the impact we have on our surroundings, plays a key role in measurement and that it's our experience of the universe that converts it from just imagined to real.

Is it possible that human consciousness can explain some of the quirks of quantum mechanics?

Quantum measurement

The rules that govern the universe are called quantum mechanics. We are told by quantum mechanics that we are in a nondeterministic world. It's impossible when it comes to the world of tiny particles, no matter how clever the scientists are or how well they know the experiment's initial conditions. Do you know how the force works on a protons? It's not certain where it's going to be a few seconds from now, only a set of probabilities.

There's a spooky action that's confirmed in new experiments.

We don't know why that split happens, but it's a problem for a different day.

Physicists don't know what answer they will get when they perform an experiment on quantum systems. The probabilities of these levels are predicted by the equations of quantum mechanics. Once scientists know the energy level of the electron, for example, they know exactly what it will do, and that's when the universe becomes deterministic.

There is no other theory in physics that operates the same way as this one. The act of measuring is special. There are many quantum interactions in the universe. Does the same flipping happen when no one is looking?

The role of consciousness

The standard interpretation of quantum mechanics is to ignore all this and focus on results. The world of the subatomic particles is inscrutable and people shouldn't try to make sense of it. Scientists should be thankful that they can use the equations of quantum mechanics.

Many people don't like that. There is something special about the process of measurement that is only found in quantum theory. It becomes more striking when you compare measurement to other interactions.

In a distant gas cloud, nobody is around and nobody is watching. The rules of quantum mechanics should apply if there are two atoms bumping into each other. It's just one of trillions of random interactions that humans don't observe. The interaction is still indeterministic according to the rules of quantum mechanics.

Scientists can measure and record what happens if the same two atoms are in a lab. The rules of quantum mechanics tell us that when a measurement is made, indeterminism flips to determinism.

These two cases are not the same. The particles interact with one another. There shouldn't be an escape from quantum rules that say the outcome should be indeterminate because every step of the measurement process involves particles at some level.

The only difference between the two scenarios is that one is a conscious, thinking observer and the other is not. The collapse in quantum mechanics is dependent on consciousness.

Dreams of the universe

We think there is something special about consciousness because it's so important to us. Animals are the only conscious beings in the universe. One way to interpret the rules of quantum mechanics is to think of a measurement as the intervention of a conscious agent in a chain of interactions.

This line of thinking requires consciousness to be different from everything else. Scientists could argue that consciousness is just the sum of many different interactions. There is no end point in the chain of measurement. If it's true, what scientists do in the laboratory is the same as what happens in random gas clouds.

There is a long tradition in philosophy and theology of the idea of consciousness being different from the material universe.

It will have to remain in the realm of philosophy and speculation until someone can figure out a way to separate consciousness from the rest of the physical laws.

The series describes possible interpretations of quantum mechanics.