The hand hypothesis

Sam's hand swelled up on Starling Dodd. We discussed the various factors and came up with different hypotheses. One was that a heavy rucksack was restricting circulation. So the next day he walked without a rucksack and his hands were not swollen, as shown. So is the hypothesis proven. It's not that easy. It wasn't a controlled experiment. We didn't walk for as long. we didn't climb as high. The weather was roughly the same. One event doesn't constitute a pattern. We'd need a lot of repeat readings and repeats in subtly different conditions. My simple Physics experiments involve situations that are simple to control. That's why they are the original laws - they were the first to be discovered. But more complex situations are much harder to control and prove.