system
Given the following post, respond as if you're commenting on Reddit:
human
Thought experiment: Could a spinning blade rotate so fast that it would feel like a solid surface and act like a solid disc?

I've wondered about this thought experiment for a while.

The blade could be imagined as a line with a defined length. Would the situation be possible theoretically since the radius spins so fast that the empty space is essentially filled?

Theory aside, could this be possible in real life? Maybe the object could be a pie slice angle so that more space is filled as it rotates?

Edit: Thanks, all! I appreciate the comments. I had always thought of this as Newtonian, but failed to realize the possibilities of a quantum mechanical explanation.
gpt
Well the thing is that in order for such a blade to rotate fast enough that you couldn't cut yourself on it, it would have to be rotating at something like the characteristic vibrational frequency in solids, which is around 10^12 per second (a common estimate for the attempt frequency of regular reactions).

The speed of light is 3x10^8 m/s, which means that the radius of your circle would have to be less than around 0.1 mm, and more realistically at least 10 times as less to start to mimize relativistic effects at the tip.

So basically not practically, but it might be "possible" for extremely small systems.