Ideas are powerful, particularly ideas that help to shape our understanding of what reality is. Stuart Brand once said that the only real news is the revelations that science brings us about reality. What I’d like to do with this blog is to take a host recent science news and tell you a story about that news. I’d like to build a new framing for how we think about reality, one that’s based in real, solid news from the scientific frontier.
This aim is, by nature, philosophical. The news that I present and the framing for it — none of these things are novel. I’m not the first person to write about the multi world interpretation or to explain how spooky action at a distance has been observed. The framework for thinking about it, isn’t something I’ve seen elsewhere. I’ve been calling it quantum rhetoric. Quantum because it’s rooted in what quantum behavior tells us about the nature of reality; rhetoric because it provides a coherent, rich vocabulary for thinking and conversing and understanding each other and our world.
If physics is the study of the laws that describe the behavior of all things, quantum mechanics is the search for equations that generically describe the actions, movement, and relationships of the smallest, most fundamental particles in existence.
An interesting property has recently been discovered about quantum mechanics. That’s that many things we can know about the minute movements of these tiny particles aren’t fixed, but rather probabilistic. Our modeled understanding of an electron’s movement, for example, used to be simply expressed as a set of concentric rings, each ring representing a different “level” of energy. These rings, in a sense, are a lie. Electrons don’t move in set trackways about a photonic center. Their true location about a nuclei is better expressed as an electron cloud – a map of probabilities that depicts where an electron resides at any given moment. The behavior of the electron isn’t tracked — it’s probabilistic.
It turns out that probabilities are a fundamental property of quantum behavior. Feynman shows that light,its particle wave duality that’s never been fully resolved, at least not at a high school physics level of understanding, is largely a probabilistic process as well. The location that a light beam ends up is but the sum of its probabilities.
There’s some fishiness to these probabilities, however. A fishiness that has long perplexed even the most leading of lights in the physical field. Einstein called it “spooky action”. In many ways, this observed fishiness breaks laws — the speed of light limitation for how fast information can travel, probability itself. You can see this fishiness at work in two ways. David Deutsch, in his book The Fabric of Reality, outlines one such experiment.
The dual slit experiment, as it’s called, involves setting up a screen in front of a light source such that light can pass through two slits in the screen. Light particles are then sent through the screen, one particle at a time, kind of like a ball being thrown between slats in a fence. If the ball was covered in paint and there was a white wall behind the fence, when you throw a single ball, what pattern would you expect to see on the white wall?
The naive, normal physics of everyday things rules would suggest that you’d only see a single mark from the ball, or one shaft of light in the case of light particles. The reality, however, is much stranger. What you end up observing is a wave like interference pattern. One particle was sent, but it appears to be interacting with unseeable and immeasurable other particles, leaving not a single shaft of light on the wall, but instead a wavelike pattern, of interfering ripples.
You can solve this “problem” of waves and get the light beams to act in a rational manner in two ways. First, by closing off one of the slits in the fence. Second, by placing a sensor at one or both of the slit openings, such that you can track with absolute certainty which of the two slits the single light particle passes through. In both of these cases, the light pattern on the wall resolves to a single shaft of light. Something about observing the light passing through the slat seems to “fix” the strange interference problem.
Why? How? These are questions that physicists have some theories about, but as of yet have not been able to settle on a single, unifying framework for understanding why light seems to act like a probabilistic wave in one instance, and a normal “ball” in the other.
Further experimentation has only led to more puzzles of the same type. One such example is entangled particles. What we now call quantum entanglement was most famously observed by two particles being bound in extended unknowablity. The classic entanglement experiment goes as follows.
Take two particles that have been blasted apart by a laser. These particles are known to be spinning in opposite directions, yet which particular particle is spinning left and which spins right, is unknowable at the time that they are split. This state, of being in a joint unknowingness, is called quantum entanglement. The particles are entangled in that their final destiny, left or right, is bound to the fate of the other, yet both are in a state of suspended decision.
This may seem like a strange way to talk about the spin of two particles. If these were balls in an urn, one black and one white, it’d be a simple calculation of probability to figure which ball you might get when pulling one out at random. When you reach in, you have a fifty fifty chance to get the white ball. The same goes for the black ball — fifty fifty. Once you’ve drawn the white ball, you know with absolute certainty that the ball you’ve left behind must be black. So which ball will you get when you pull one out? It’s a toss up.
Entangled particles are like this urn, with a black and a white ball, with one exception. Instead of reaching into the urn, let’s say that you bounce one of these unknown particles through a filter. The filter is set up such that only left-spin particles can pass through it. If we took a ball, while blind folded, from the urn and then threw it to a judge who would accept only white balls, we’d expect the ball to be accepted half of the trials. We’d expect the same for particles passing through a “left only” filter. What actually happens is far stranger. Instead of a fifty percent pass rate, we get one hundred percent. If you change the filter, from a left filter to a right one, your pass rate remains at 100%. The particle that passes through the filter is the right spinning particle and the particle not passed through spins left.
That’s the same as saying I’m going to throw balls at a white judge, and then only drawing white balls. Then you say, ok, I will only throw balls at this black judge, and then proceeding to only draw black balls from the vase. The vase still contains two choices, black or white, but you’ve managed to predict with 100% certainty which ball you will draw based on the type of judge that looks at your ball.
How can these particles manage to spin the correct direction, every time? Are the particles communicating? Are you the luckiest physicist in the world? Einstein was perplexed by these results, so much so that he termed the phrase “spooky action at a distance” to describe how these particles managed to spin exactly opposite yet the correct way for the filter every time.
These results of entanglement and the infallibility of the filtering mechanism have been replicated at great distances. The spooky action persists. Are the particles communicating? Are they traveling back in time? How is it that a single physicist can be so lucky, so many times in a row?
If the particles are communicating, physics has a problem. That problem is called the speed of light. Einstein himself showed that nothing, especially not information, can travel faster than this speed. The synchronized behavior of the particles is instantaneous, however. There is no delay between measuring an unknown particle with a “left spin” filter (thus making it left spinning) and observing a particle with right spin. If lightspeed still matters, then these particles aren’t communicating.
What else might explain the physicists unfathomable luck?
David Deutsch posits that the explanation for this is simple — that we don’t in fact live in a universe, but rather a multiverse, a multiverse constructed out of all the possibilities that can physically exist. Our multiverse is defined by the probability set. One universe of a black ball drawn, another with a white.
This multi world interpretation, or MWI as it’s colloquially known among the physicist set, explains the spooky action as follows: entangled particles are an urn of two balls, one black one white. There are two different universes that exist, forward in time. One universe in which you pull a black ball. Another in which you pull the white.
You can deterministically decide which universe you’d like to exist in. You do this by picking a filter through which you would like to observe the world — either the black filter or the white filter. Selecting the black filter and then applying it to the urn, or entangled particles, fixes you into the reality where the ball is black.
The dual slit experiment and the filtered entangled particles share one key commonality: the power of observation and its undeniable role in fixing the observed results. This is important. The probability of what ball will be picked has moved from the random chance of the universe to an explicit choice on the behalf of the observer. The observation is the sound of a universe, of two possible, being chosen.
Quantum rhetoric is simply this: the reckoning of existence in a branching multiverse, that becomes fixed into a coherent reality.