system
Given the following post, respond as if you're commenting on Reddit:
human
[Superman] I find a rock, paint it green, then spray it to make it glow. Could I use this to placebo effect Supes into giving up?

Or would he know the difference between green glowing rocks and kryptonite?
gpt
I think it would depend on your distance. IIRC he can feel kryptonite's effects from a couple feet away, so if you were in front of him with it, he'd be able to tell the difference. There's also his super vision, he might be able to see through the rock and know it's not kryptonite.