As I suspected, the first image wasn't what my client wanted at all. Here's my second try at a "cosmic" background for his PowerPoint presentation, going on what he asked for. He wanted a dark background with mathematical shapes. The type would be in white over the design. I didn't want to make anything too contrasty or bright so that it would not conflict with the type. I was glad to find spiral and grid shapes in Photoshop "brushes" free to download. I have just set up Photoshop on the restored main system and I am trying to reconstruct my working environment.
Photoshop CS4, about 11" x 8 1/2", June 25, 2013.