[HN Gopher] Why 'Prince Rupert's Drop' Glass Is Strong Enough to...
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Why 'Prince Rupert's Drop' Glass Is Strong Enough to Shatter a
Bullet (2023)
Author : susam
Score : 60 points
Date : 2025-04-09 23:55 UTC (2 days ago)
(HTM) web link (www.popularmechanics.com)
(TXT) w3m dump (www.popularmechanics.com)
| test1235 wrote:
| video in lieu of the article's broken link:
|
| Bullet vs Prince Rupert's Drop at 150,000 fps - Smarter Every Day
| 165: https://www.youtube.com/watch?v=24q80ReMyq0
| HelloUsername wrote:
| The article is also from 2023.
|
| It's funny to see how topics on reddit
| (https://l.opnxng.com/r/Unexpected/comments/1jvhcme posted 2
| days ago), 9gag (https://9gag.com/gag/aW4vpKd posted 1 day ago)
| and HN (posted today) are always connected.
| mystraline wrote:
| It reminds me of Cory docotorow's comment of something like
| 'there are 5 social media sites and everything is just copied
| from one another'
|
| HN isn't immune either, given that karma provides 'rights to
| punish views and accounts' (downvoting). And it makes a great
| strategy to make a whole lot of socks with 520 karma, and
| selectively kill comments and stories you don't want.
| actuallyalys wrote:
| I'm sure sock puppets and voting rings play a role, but
| "this link was interesting to a bunch of people on sites
| with some overlap in interests and demographics" seems a
| simpler and better explanation.
| dyauspitr wrote:
| The best part is if you melt away the weak tail, all you're left
| with is the strong bulb.
| tifik wrote:
| Would/does that actually work? Its been a while since I watched
| SED Destins video about it, so I dont remember if they
| experiment with that. But intuitively, heating the glass so
| non-uniformly that the tail would melt and the bulb remained
| solid enough to keep the internal stresses intact, wouldnt that
| steep temperature gradient within the crystaline structure
| cause the entire drop to break?
| maxbond wrote:
| In this video someone does it and it seems to work.
|
| https://youtube.com/shorts/ERDmKW65t38
|
| But it's a very small drop and they don't melt it all the way
| to the bulb. I imagine that it could shatter in some
| circumstances.
|
| (Incidentally glass isn't a crystal, but that's just a
| nitpick.),
| prox wrote:
| Is glass still considered a form of liquid? Think I
| remember reading something about that years ago.
| sparky_z wrote:
| No, that's a classic misconception. People claimed that
| windows "flowed" because really old ones were thicker at
| the bottom, but that was just how some old window glass
| was made.
| dasil003 wrote:
| Yeah if you're installing an uneven pane where would you
| orient the thick side?
| Hikikomori wrote:
| The bottom.
| gweinberg wrote:
| I think the basis of the claim is that glass doesn't have
| the same kind of phase transition that a crystalline
| solid would. It just sort of gradually becomes more
| liquid-like as you heat it.
| s0rce wrote:
| No, its disordered (ie. not a crystal) but not a liquid,
| it won't flow like a viscous liquid.
| s0rce wrote:
| My comment was a bit over simplified, they do flow, but
| the time scale exceeds the entirety of human history [1].
|
| [1] https://doi.org/10.1119/1.19026
| maxbond wrote:
| Similar to the misconception that Earth's mantle is
| liquid. It isn't, but time is deep enough for solid rock
| to flow.
| undebuggable wrote:
| My first thought was to see it under hydraulic press and the
| internet delivered.
| darkwater wrote:
| When was this article written? Last update is 2023 (so the title
| should at least reflect this) but down in the article talks about
| Gorilla glass by Corning as a novelty with possible future uses
| in smartphones.
|
| Sent from a Gorilla glass smartphone with a corner almost broken
| ^^;
| jccalhoun wrote:
| youtube says the mythbusters video is from 10 years ago so it
| was written sometime since then.
| darkwater wrote:
| And according to Wikipedia [1] the first commercial use of
| Gorilla Glass was the original iPhone in 2007, even if the
| name was officially coined in 2008
|
| [1] https://en.m.wikipedia.org/wiki/Gorilla_Glass
| dragontamer wrote:
| Prince Rupert's Drop is strong at compression but weak enough
| that your pinky finger can shatter it.
|
| These 'hardness' stats are just marketing bullshit dressed up
| in barebones material science. They know most people haven't
| studied material science or understand what 'hardness' means.
| dghughes wrote:
| Someone needs to invent a way to make tank armor out of Prince
| Rupert's Drop glass.
| undebuggable wrote:
| Once I was stuck down a youtube rabbit hole of someone testing
| anti-tank portable launcher against increasingly thick
| ballistic glass. The conclusion was that no glass can resist
| anti-tank projectile. Maybe large enough Rupert's drop glass
| could?
| qwerty456127 wrote:
| What it takes to actually destroy it (by applying pressure at a
| wrong point)?
| ninkendo wrote:
| A tiny amount of pressure applied to the "tail" of it shatters
| the whole thing instantly, that's one of the coolest things
| about it.
| aragonite wrote:
| There's a pretty amazing video here showing a Prince Rupert's
| drop defeaing a hydraulic press:
| https://www.youtube.com/shorts/ns7PQjjqHIo
| dzdt wrote:
| Yeah its not really what it looks like though. They put
| cylinders of soft metal in place of where you would expect the
| press to have hardened steel.
| aragonite wrote:
| Has this been confirmed? The original channel also posted a
| comparison video [1] showing what seems to be the same
| cylinders tested against titanium and tungsten cubes (though
| it's difficult to be sure they are identical)
|
| There's also footage from another channel [2] showing a
| Prince Rupert's Drop bursting at 20 tons with significant
| damage to both the steel plate and the press.
|
| [1] https://www.youtube.com/watch?v=4SuPFbeqqKU
|
| [2] https://www.youtube.com/watch?v=A6NUNroyUys
| KTibow wrote:
| Slowed down: https://youtu.be/tRUngxK2yXY
| philjohn wrote:
| You can see the steel deforming - definitely soft steel.
| ChrisMarshallNY wrote:
| They must have gotten the librarian in the video from Central
| Casting.
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(page generated 2025-04-12 23:01 UTC)