[obastani]

I'm not sure about that. If Mary knows all the physics of light, she can design and set up a sensor to detect the color of the apple and the instructions, just like we have sensors that detect ultraviolet and infrared light. Just as we will never know how it feels to "see" ultraviolet light, this thought experiment is about Mary's subjective experience perceiving color, not her ability to determine the color of the world around her.

[kelseyfrog]

Mary is using sensors either way: they either come pre-installed or after market.

On a more serious note, I'm taking the question in the article at face value, "Has Mary learnt anything new about the colour red upon seeing the colour for the first time?" If the author really meant it to be a question about the subjective experience of seeing, they should have simply written a better question.

[jiocrag]

Your confusion is not the author's fault. You ignored the parameters of the thought experiment, which clearly state that she can discern colors without "seeing" them. The question is whether the subjective experience of "experiencing" color adds new information.