I had a few hours to kill in San Francisco while Jennifer was volunteering at a wine event, so I went to the California Academy of Science, which was on my list of places to go one day.
To be honest, as a science museum, it's a bit undewhelming: I got through it in about 3H and that included their planetarium show which was more an Imax movie (although it was actually a good one).
For the rest, it was more a museum on animals of many kinds, which was interesting. It was however lacking on sience in general: computers, optics, genetics, medicinal sciences, math, physics, computers and so forth. On the upside their aquarium was good.
the biosphere was reasonably good
for people who don't dive, lots of nice things you'd see during dives
Anyway, it was an ok few hours, but not the best science museum I've seen in the US, I expected a bit more after having seen some in St Louis, Portland, or other places.