Redefining Reality

No subject is bigger than reality itself, and nothing is more challenging to understand, since what counts as reality is undergoing continual revision and has been for centuries. For example, the matter that comprises all stars, planets, and living things turns out to be just a fraction of what actually exists. Moreover, we think that we control our actions, but data gathering systems can predict, with astonishing accuracy, when we will get up in the morning, what items we will buy, and even whom we will marry.