Welcome to Our San Francisco, a yearlong project looking at 150 years of the city’s history. Each week a different chapter will be explored in the newspaper, on SFChronicle.com, in Peter Hartlaub’s The Big Event blog on SFGate.com, and on social media at #OurSF. This week’s chapter: San Francisco’s m useums. It must have been a chaotic morning at the California Academy of Sciences building on Market Street after the earthquake hit in 1906.