system
Given the following post, respond as if you're commenting on Reddit:
human
[DC] Sharpness is a property that comes from thinness and high strength. Does this mean that Superman's hair-thin impossible-to-break hair strands could be really sharp? If I run my fingers through his hair and it snags can I get cut?

If I press my hand against a steel wall, even if I'm pressing very lightly, something has to give, either the wall or my hand. Thankfully, as the force is distributed over a large area, no one part of my hand feels that much stress and my skin just deforms a little bit.

If I press my hand against sharp steel knife, even lightly, that force has to go somewhere, and either my hand or the knife has to deform. Unfortunately, unlike with the wall the force is concentrated into a very small area. The result being obvious.

If I run my hand through Superman's hair and it happens to snag, that's all the force of that movement concentrated in a very small area. It's probably not going to be the hair that deforms.

So let's say it's a worst case scenario, I try to pull my hand away from Superman's head pretty damn quick for some reason. I'm talking about "I accidentally hit my friend in the nose while moving my arm it actually hurt a lot" type speed. If one finger gets snagged in a hair does it chop it off?
gpt
Not in your scenario, because the hair is also very flexible. It'll just bend out of the way, unlike a solid knife.

However, a strand could definitely be used to cut something, if secured and pulled across/through it like piano wire.