93. Underestimating inertia as a factor of stability
Besides general concerns about complexity, competence, safety-checking feedback mechanisms, and hundreds of other factors that keep a system safe and steady, it is possible to use Gott's formula (see chapter on indirect estimation of risks) to estimate the future expected lifespan of a system, based on how long it has already existed. For instance, there has not been a major meteor impact in at least 11,000 years, so it is not likely that one will occur tomorrow. Or, the pyramids at Giza have been in place for more than 4,500 years, meaning it is not likely they will topple or erode away in the next 100 years. Accordingly, this lets us take into account the inherent inertia of systems as a factor of judging their stability. Even if a system seems to have certain fragility, if it has been around for a long time, it could very well be more stable than we think. Correspondingly, if a system is extremely new and untested, although we consider it foolproof, we cannot confidently assume that it will not collapse at some point, since it has not built up a track record of stability.