Time to collision, human risk management

Imagine a ball approaching you through the air at a pace. Sports psychologists have been fascinated by how, as humans, we can accurately predict the approach of objects and intercept them with such precision.

Think about catching in the slips in cricket, striking a baseball and intercepting a high velocity pass in hockey. All require us to visually assess and then react.

Interestingly, we cannot accurately conclude 'time to collision' by calculating the speed of an object and its distance from us. This is because of the limitations in our binocular vision.

What we now understand is that we use two factors: the known size of the object approaching (based on experience) and the rate at which that object is expanding.

Essentially, the optical variable called ‘tau’ (using the above criterion), which is defined as “the inverse relative expansion rate of the object’s image on the retina”, is what allows us to rapidly assess and then monitor how and when we will interface.

Risk management is precisely this: understanding our known experience and the rate of change of that experience.

This is why, when predicting risk, we need to strive towards having all the data and information possible.