As part of its new groundbreaking marijuana exhibit, Altered State, the Oakland Museum of California (1000 Oak St.) is hosting a Q-and-A session with Dr. Robert Martin of the Association of Commercial Cannabis Laboratories. Altered State highlights the history of weed in California and its various cultural strains (har har). It’s a pressing topic, considering that recreational-marijuana legalization will be on the state ballot this November. To further inform the debate, OMCA is holding monthly “Ask an Expert” sessions during its Friday Nights @ OMCA block parties. (Pro tip: During that time, admission is half price for adults and free for kids.) These will feature experts on cannabis law, health, economics, and politics. The next one, featuring Martin, will take place on May 13 from 6–8 p.m. and will be a prime opportunity to ask policy-related questions.