Motion and Perception.

Question

What is the least amount of motion detectable by the human eye?

We can easily see a car pass but even if we stare at a clock we cant see the big hand move in real time from minute to minute even though it is in motion.

So what is the least amount of motion the eye can detect?

Measured in micro miles per hour? Inches per hour?

Answer 1

Motion pictures run at 24 frames per second, so that is a good estimate of what appears to be fluid motion. It is said that 1/10 second intervals are noticeable.

The big hand of the clock runs through 2pi radians in 1 hour.