Ruperts drop

 I just watched a video about the Ruperts drop - A very interesting piece of shaped glass, thats shaped like a tadpole, that is nearly indestructble on the head end. However, if you so much as chip the tail end, it will explode in to millions of pieces. 

I found out how this works however, the way it holds itself together is that when it's made, is that it gets taken out of the furnace on the stick, then the glass maker lets some of it drop in the water. As it falls, it still lets a small string of it stick to the remaining blob of glass. It hits the water. The string (Still molten) disconnects to the blob of glass on the stick. The string falls into the water. The whole thing cools. 

Now, when we take it out, it looks like this. 

The reason it dosn't shatter when hit with a hammer on the large end, is because the outside cools first when it hits the water. The inside is still hot. As the inside cools, the outside has already put itself into place. 

Now, when something heats, it expands. Likewise, when it cools, it contracts. The inside contracts as it cools. This means that it puts pressure on the outside, as to fill the space made by the contracting glass, it also has to contract. It doesn't break. It compresses. Now we have a very strong piece of glass. 

And I mean VERY strong.

https://img.huffingtonpost.com/asset/5912fb961600002000c5a684.gif?ops=scalefit_630_noupscale

However, the string is obviously very fragile, since it's long, thin, and made of a fragile material. It's still part of the framework holding together the ruperts drop, however. It's all stable, until the string breaks. 

Once it breaks, that part is unstable, as all the potential energy used to hold together the drop is now gonna be released. That part now starts losing the connections between the glass particles. Imagine it's like dominos falling. 

As one bit breaks, the bit just up it also starts "exploding". This keeps going until it reaches the major part of the droplet. Since all of it has to be pulling in, now that the end of it has broken, it can't hold itself together.

It is now a pile of shattered glass.

Rather interesting, isn't it?

https://www.youtube.com/watch?v=xe-f4gokRBs