Count the discs hidden in moving noise. Every single frame is statistically uniform noise — a screenshot-reading agent sees nothing — but human motion perception segments the spinning discs instantly.
This is a client-side preview so you can experience each check. Inside a real Carrier experiment, challenges are generated server-side, answers are verified server-side and never appear in any client payload, and every result is recorded on the participant's run and interleaved into the session transcript.