Quantum bayesianism is a way to use the laws of quantum physics to make decisions. It uses a mathematical approach called Bayesian probabilities to look at the probabilities of different events happening and then making decisions based on the most likely outcome. Quantum bayesianism uses the uncertainty principle, which states there is a basic uncertainty about what will happen in the future, to understand how to make decisions based on our current knowledge. This means that we use mathematical equations to figure out what is likely to happen given the current information we have, and then decide what to do based on the most likely outcome.