system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: Why do scissors enter 'slide mode' sometimes?
gpt
Low friction, very sharp: sschhhhwip ooh baby

High friction, blunt: sshcklaclacklackack ah fuck

Sharp scissors cut with very little force, so there isn't enough energy built up in the pressure of the blade against the paper to rip very far. This keeps the tear immediately next to the blade, so the blade continues to cut with very little force.

With a blunt blade, there isn't enough force to rip the paper against the blade until the tension is much higher, then once the paper begins to tear it can tear further and probably not in a straight line ahead of the blade. So then the blade is pushing against un-torn edge instead of the cleft of the cut and the problem starts again.

You can increase the chances of the sschhhhwip by sharpening the scissors and by slowly closing the scissors as you push, keeping the cut in front of the blades and applying both of them to reduce the required force to cut the paper.

If you push hard, you're more likely to rip the paper.