In the quantum world view, events in reality are not pictured as coming in predetermined, connected sequences of cause and effect. But they aren’t random either. All events can now be seen as governed by probabilities. Which subatomic particles will jump to other energy levels at any given instant can be described only by laws of probability, not chains of causes and effects. All larger events are shaped by those subatomic events.

Normally, an event or an object at our level of reality is the average of quintillions of subatomic events. Most of the time, the events we see at our level are high-probability events, and they fit together to create the familiar Newtonian pictures and patterns we have come to expect in everyday life.

But quantum theory leaves open the possibility that occasionally, when enough unusual events at the subatomic level coincide, they cause an event at our level—a hurricane, a supernova, a tornado, an avalanche, a failed bolt in an airplane, a mutation in a bacterium, or a sillytumble (I made that up). All these events have causes; none of them is “uncaused”. The problem is that the causes aren’t neat sequences of earlier events. In principle, we can’t predict these outcomes in advance because we can’t calculate the sums of all the tiny events in the chain. Weird things – things outside of the usual Newtonian causal model – sometimes happen.

And it’s not just that too many factors are involved. Even some simple systems with only two or three objects and forces acting on them evolve in ways that defy the best of the old cause-effect. 

The possible results of the system depend on initial conditions of all parts of the system. Tiny changes, some of them quantum changes, in any of these parts at any time during the unfolding of events may lead to very different outcomes. The possible outcomes multiply until, in practical mathematical terms, they can’t be calculated.

                          

                   Inside the eye of Hurricane Katrina (credit: NOAA, via Wikimedia Commons)

For example, we can only say after the hurricane has passed that five days before it hit, some of our models had been indicating near-certainty levels of the hurricane’s making landfall on the Gulf Coast. Then, the evolving odds that it was going to hit a specific site—New Orleans, for example—began to approach 60 percent on Friday and 95 or 99 percent by Sunday. Tiny jumps by particles, even some subatomic ones (what physicists call the “butterfly effect”), right back to the hurricane’s genesis off the coast of Africa, favoured and eventually selected one outcome over all the other possible outcomes.³

In this hurricane scenario, gradually, a winning candidate emerged. But before it hit, which outcome that would be was not just unknown; it was unknowable. Unlike the Newtonian world view, the quantum worldview says that the outcomes in real-life sequences of events are never certain, but are always to some degree predictable.

Unlike the Newtonian paradigm, the quantum one has also opened up the possibility that we humans really can influence probabilities by skilfully executed action in the real world. 

We can act at the macro level and increase the odds of some of the possible future scenarios occurring and some of the others not occurring. If we are sane, we choose to enhance the odds of the futures that will make us healthier and happier while decreasing the odds of the futures that lead to us getting hurt, sick, or killed.

The odds that the flap of a butterfly’s wing will cause a hurricane or a rockslide are extremely remote. The odds that I will not get hit by a rockslide if I hear a roaring and duck beneath an overhanging shelf of basalt are much better. I can react successfully to the unforeseen. 

The odds that a field in April, left alone, will be full of corn ripening by October are extremely remote. The odds are much higher that the same field will contain a harvestable corn crop if I seed it with corn in April, then water and weed it for the next five months. Human knowledge and skill enable us to intervene in the flows of events around us. At present, we can’t stop the hurricane, but our computer models, when fed enough data, can tell us when we need to get out of the hurricane’s way if we want to have reasonable odds of going on with our lives.