Pay particular attention to Caleb’s play with feathers. At first he places the feathers in the updraft and opens his fingers right away so he can watch the feather’s ascent and exit through the top. But on his last two trials with the feather he seems to hold the feather somewhat more tightly. You can see the wind bending the feather upward in his hand that anchors the feather in place. We may speculate that at that moment of holding the feather more tightly he has shifted his thoughts from observing the effect to augmenting the visibility and magnitude of the cause. It is not too much of a stretch to say that he has invented a sort of wind meter to measure the force of the updraft. How much does the wind bend the feather? How much do I have to loosen my grip before the wind forces the feather out of my hand? We can accept his play as an analogue to how a scientist reveals the magnitude of the forces of nature.