 Static belief change occurs in everyday life when we receive information about something that can quickly change, so that the information can become “stale” (i.e., incorrect) just after we receive it. This happens, for example, with our knowledge of the price of a high-volume, high-volatility stock during trading hours: if we check the price and then look away for the rest of the day, we only know the price at the given moment in the past and cannot guarantee that the price remains the same, even right after we checked it. Therefore, we only know the price of the stock in the past—not in the present—even though for practical reasons we sometimes operate under the fiction that the price remains constant after we checked it and therefore speak as though we know it (even though we really do not). 