Prince Rupert's Drop can withstand ANYTHING video shows a man firing a point-blank shot at the glass

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Anyone ever hear of this? Crazy. Watch the video.



http://www.dailymail.co.uk/news/art...Rupert-s-Drop-does-nothing.html#ixzz4fStZcRWR








Prince Rupert's Drop can withstand ANYTHING: video shows a man firing a point-blank shot at the glass - and it doesn't break

By Daily Mail Reporter

PUBLISHED: 00:57 EDT, 27 April 2017 | UPDATED: 01:20 EDT, 27 April 2017

A man caught the moment in slow motion video that a piece of glass known as the Prince Rupert's Drop withstood a bullet fired at close range.

Destin Sandlin, an engineer who has a YouTube channel called Smarter Every Day, likes to experiment with trying to destroy the almost indestructible (unless its tail breaks off) tadpole shaped glass piece known as the Prince Rupert's Drop.

Because of the way tension is distributed throughout the glass, the head of it can withstand extremely high stresses, such as hammer blows or Hydraulic presses, while it will normally the entire glass shatter if the tail is broken, or even just wiggled.
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You should check out the youtube channel of the guy doing this video. His work has been posted on this forum a number of times.

All his videos in order can be found on his primary website.
http://www.smartereveryday.com/


He has quite a few gun related videos that are quite good.

Check out this one, it is about making one of the glass drops.


Here is the previous video with a .22



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Mount it securely in something and see if it breaks. Bet it will
170,000 fps? Wow, I thought my .357 loads were hot! :eek:
 
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170,000 feet per second?
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170,000 fps is frames per second, not feet per second. It refers to the camera not the bullet. Its a bit more than 5 microseconds per frame and why you can see the bullet, its spin, and fragmentation. I want one of those cameras! "Normal" video is 16.6 milliseconds per frame, or ~3000X slower.
 
I've seen that video. The news headline sure made me look when it first came out.

I learned a couple things about Rupert's Drop. it is interesting how it is made and how it reacts to impact. I also learned if you shoot it, it still breaks apart no matter what the headline implies. :D
 
It breaks because a bullet fragment hit the tail and the destruction propagates at miles per second speed to the front. In the other video there are some impacts where the tail is not hit and the whole thing bounces away and remains intact.

This same pre-stressed construction idea has been used to produce "metalic glass" ribbons by pouring molten metal on to cold rotating wheels to produce materials with some unusual properties, but I'm not aware of any commercial usage yet, although in 2016 some news about a procedure to make gears for robots out of "bulk metalic glass" came out of JPL:

https://www.jpl.nasa.gov/news/news.php?feature=6684

After re-reading this article, it mentions metallic glass has been used in "everything from cellphones to golf clubs" which if true is something I've never noticed being promoted by the manufacturers.
 
wally said:
After re-reading this article, it mentions metallic glass has been used in "everything from cellphones to golf clubs" which if true is something I've never noticed being promoted by the manufacturers.
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You think they could be broadly interpreting that to mean products like Gorilla Glass, used on some cell phones, where in the production process some Sodium atoms are replaced with Potassium (an alkali metal) atoms?


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No, metallic glass is an unintuitive term, thanks to the order of the words... it is a metal (so metal-colored and opaque), but the physical arrangement of the atoms is comparable to glass (amorphous, aka disordered) compared to the extremely organized/predictable, crystalline structure of typical metals. Note that the constituent elements of these metallic glasses are familiar "normal" metals (Titanium, Copper, Zinc, Magnesium, etc), but due to the exotic processes they use, they are able to cool liquid metal so fast that the atoms are unable to form the crystalline structure before they cool to a solid form.

As I understand it, metallic glasses have been used on some small, random parts in cell phones as a sort of "test bed" to gauge increased use in other parts of the phone after they have been proven out. That information was told to me probably 5 years ago, though, so it is likely outdated by now... I'm sure the primary limiting factor for this technology is cost, compared to traditional manufacturing methods.
 
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That amorphous technology is akin to powder metallurgy where dissimilar elements are compounded and then compressed into working parts. The normal process of casting and cooling with different temperatures where the liquid starts building crystalline structures is avoided, preventing the lower temp material from segregating or being squeezed out.

That sort of blended material is also why early iron made from bog ore and then refined by hammering had much different characteristics when compared to later cast irons and steels. Wrought Iron from that era has a silicate component which also prevents rusting. The newer products are actually too "pure" as the alloying elements were held to much smaller quantities.

It seems we are coming around full circle by adding elements which can't be combined with normal methods and not allowing crystallization to affect the end product.
 
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