Here's Mum at the end of the church service:
What are you laughing at, Mum?
It was the line:
Classrooms and labs, loud boiling test tubes, sing to the Lord.
I don't think she would have laughed except that I started laughing. You know: church laughing, where you don't make any noise and you try not to snort, and you just shake trying to contain it. I couldn't wait to tell Brother Atlasta, the atheist scientist. "Oh, that's what that noise is for," he said.