Walking into the Mel Bochner show at Marc Selwyn Fine Art in Los Angeles is a little like entering an observatory, but you are looking down instead of up at the sky. On the concrete floor are simple chalk marks, drawings of circles and lines and lists of numbers. Strategically placed among them, punctuating the shapes and charts, are large chunks of richly colored glass that might be emeralds, rubies and sapphires glistening in the reflected light like stars. Minimal? You bet, yet memorably and unpredictably uplifting nonetheless. The title of the show and the story behind it add to the intrigue. Called “Theory of Sculpture: Fontana’s Light,” the pieces extend the visual language of the influential Italian artist Lucio Fontana, who worked with this same broken glass in the 1950s and ‘60s.