Kiddo, at the tender age of three, is already learning fundamental scientific concepts. (We always knew he was brilliant.) His current experiments are designed to gain an understanding of the second law of thermodynamics.
This would be the law regarding the ever increasing entropy of the universe. In short, you can stir cream into your coffee and you will get swirls of cream in coffee followed by creamy coffee. But you can’t unstir the coffee to make the swirls and cream come back.
Kiddo, of course, has not yet developed a taste for coffee. Thus, he is conducting his experiments with Play-Doh. For a brief time, we had rainbow Play-Doh. This was soon followed by brown Play-Doh. Kiddo did not look at all satisfied when he demanded to know: “Where the purple play-doh go?” and I explained the brown blob in his hand is where the purple went.
He has since continued his endeavors to fully grasp of this phenomenon. It's time to buy some new Play-Doh. And, now that I think of it, I need some coffee.