Tracking moving objects

There’s an old magic trick call the vanishing ball in which the magician throws a ball into the air several times and on the last time it disappears in midair. Here’s an example:

In reality, the ball doesn’t disappear, the magician palms it on the last throw, but up to two thirds of people claim to see the ball move up, and then disappear, on the last throw. This illusion takes advantage of our brain science and expectation, and it’s based on a very old evolutionary strategy that can best be as a hunting adaptation.

Predicting the future
A bird flying 30 mph can travel 44 feet in one second. When we see that bird our eyes take about 1/10th of a second to process the information (for the light hitting the retina to travel along the optic nerve and then be processed by the visual cortex). During that tenth of a second the bird will travel 4.4 feet, so our vision is always a bit off reality, the actual position of the bird should be invisible to us, 4.4 feet further along its flight path than what we see. Yet a primitive hunter could throw a rock and hit that bird – that’s because our minds construct a reality to predict where the bird will be. We can thank our evolution as hunters for this type of vision/perception


Web Development Application
Our eyes evolved to scan the environment and process massive amounts of visual data – as much as two billion pieces of information each second – but that’s image information, not text, and we can’t turn our evolution off. Reading text is really not natural to us, and when we read our brains are still in a very old evolutionary hunting mode. The point: we don’t see as much as we believe we do – we construct much of reality (and reading) in our minds. It is essential to understand that when people read that they don’t read every word (eye scan studies bear this out. See example below), so we have to construct headlines and writing for scanners.


We experience reading as a smooth experience, but this eyescan shows our eyes actually stop on words (dots) and that’s the only time we see with sharp focus.

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