In September 2007, sculptor Peter Erskine visited five cities around the United States lecturing on his solar spectrum environmental artwork called Secrets of the Sun, which uses the sun as its subject, medium, and energy source. Originally installed in the ancient Roman Forum, this interactive light sculpture draws upon the visible light spectrum to stimulate a deep emotional and physical response. Laser-cut prisms were positioned around the Roman Forum to direct light into its interior spaces, breaking it down into the visible spectrum. Mirrors directed the colored light around the rooms of the Forum, highlighting different architectural details and surfaces as the light moved and changed throughout the day. Visitors, clothed in white jumpsuits, became part of the canvas. Presented by the International Association of Lighting Designers (IALD), Erskine's presentation also discussed solar spectrum art installations in the central station of Milan, the new LAPD Headquarters, and a shade garden in the California desert.