Slowly and painstakingly, geologists are turning the imaginary time scale of Earth's deep history into exact boundaries marked on the ground with metal disks.
New tools and old-fashioned sleuthing have cleared away a century's worth of errors from our detailed picture of what the San Andreas fault did to Portola Valley in 1906.
The science of earthquake prediction is fraught with the human tendency to seek conclusions beyond the reach of the data. In this setting, even the fruitless hypothesis of sunspots is seductive.
In the new Gallery of California Natural Sciences, to be unveiled tomorrow, no one will mistake California for someplace else again.