Hi hi, Sorry if this is awful and boring. Basically what I want to work out is a way to differentiate two different liquids by touch (specifically, temperature) after shining a light on them. A thermometer cannot be used. The variables open here are the compositions of the liquid (I'm going with colour differences - perhaps a black and a white) and the light used. I also need to consider what effect the containers would have on this experiment. Any ideas, riffing off my black/white idea here, or other thoughts?