When my younger son was quite small -- thirty some years ago -- we had a prism hanging in the kitchen window that threw rainbows all about the room when the sun was right. Justin was, at the time, a big fan of STAR WARS and, in his mind, the lovely rainbows were lasers. (Or wasers -- he had some difficulties with Ls at the time.)
"Wet wasers go!" he would command and I would set the prism in motion so that the colors would dance about the room.
Time passed, as it does, and the little boy learned to pronounce his Ls and grew up; the prism's nylon string broke; and the prism itself got misplaced.