DENJIRO: This glass is in the shape of a teardrop. This is known as a Prince Rupert's drop or a Dutch tear. Let's place it in a box and cut the tip using pliers. The glass exploded into pieces, but why? This question can be answered by looking at how a Prince Rupert's drop is made.
First, we take a piece of glass and heat it up so it becomes soft. We let it fall into water like a droplet. When the glass cools, we get a Prince Rupert's drop.
When we look at a Prince Rupert's drop through a polarizing plate, we can see colors. In contrast, a piece of glass that wasn't rapidly cooled down in water has no colors. When you drop melted glass into water, the outside immediately hardens. However, the inside cools down and hardens gradually. This results in tension between the inside and outside where they pull on each other. This strain is what produces the colors.
The surface of a Prince Rupert's drop is very durable, so it doesn't break even if you scrape it against a file. However, if you damage the inside by breaking the narrow part, it will immediately shatter into pieces. Tempered glass is the same way.
If we break a Prince Rupert's drop in a glass jar, what will happen to the jar? The drop shattered into pieces, but nothing happened to the jar. Now, let's try the same thing but with water in the jar. Here I go. This time, the glass jar broke as well. When the drop is broken in midair, the pieces travel at a very high speed, but the jar doesn't break since the glass pieces are tiny. But when it's in water, the impact of the explosion causes the surrounding water to get compressed and hard. The jar broke because the hardened water struck it.
I hope energy will bring you all happiness. Our magic word is "Happy Energy!"