## No Chance

What is probability, really? A man is about to undergo cardiac surgery. The doctors tell him he has a 50% chance of full recovery. What does it mean? He would certainly be more assured if they told him his chances are 90%, but why? Ultimately, he either lives or dies. Why does the proportion of other patients who survived under similar conditions matter to him?

As a mathematical theory, probability is not hard to define, but justifying its application to the “real” world (and frankly, what could be more real than mathematics?) is not trivial at all. Indeed, it can be (and is) argued that there is no satisfactory philosophy of probability.

Furthermore, the introduction of quantum mechanics shifted the question of the meaning of probability from the philosophical to the (meta)physical. Prior to that, probability (in physics) only emerged as a result of our lack of knowledge about the state of the system. Quantum mechanics made the system itself probabilistic, and produced probabilities as its predictions. Some of the implications are explored in the following story: No Chance, by Guy Hasson.