熱脹冷縮

I don't have a very strong grip. So when I had trouble opening the cap for a bottled juice tonight, I thought I was just weak.

Occasionally these caps are too connected to the bottom ring and the links need to be cut. But it's not the case this time, as I cut loose the ring completely, and the cap still refused to budge.

I was at my wit's end. Then this simple yet elegant scientific principle dawned on me. I used the hair dryer on the cap. 「アラ不思議！」 It popped open just like that with one little twist! XD

This is why you should pay attention to science classes in elementary and high schools. Anything beyond you can forget 'cause they're either too complicated to retain after you graduate, or they keep changing.