Chat started with the friend's friend saying, "I bought a crystal ball. It's beautiful."
"Have you looked into it?" I asked.
"No, but pretty colours shine from it."
"Have you tried looking into your crystal ball to see pictures or visions?"
"No, I'm a scientist. I just see it as shiny glass, with prism effects."
"If you're a scientist, you'll be interested in science. When you focus on a crystal ball, your brain waves slow down from "beta pattern" of everyday life, to "alpha pattern" you have just before sleep."
"Oh."
"In alpha, the right hemisphere of the brain takes over. You become more relaxed, more creative, and start to see visions or pictures while you're awake."
She didn't reply. So I didn't give her the next information. Particularly as she's a scientist, and a friend's friend, not mine.
But for readers, waking pictures or visions can be deliberately focussed, such as with an intention to understand a problem, or to gain answers to questions...
Surprisingly, the explanation must have struck chords within her. Soon after, she left the room, returning with her collection of stones and crystals.
What a scientist...!