Curious property of Prince Rupert's Drop glass


33 Responses to “Curious property of Prince Rupert's Drop glass”

  1. Chris Einze says:

    Is that correct? Wouldn’t the interior be in compression and the exterior be in tension

    The exterior cools almost instantly while still in an expanded state. Meanwhile, the interior is still liquid and cools more slowly.

    The interior is attempting to contract, but is prevented from doing so by the exterior. The exterior is therefore under a compression force which is attempting to reduce its volume.

    The exterior is also pulling on the interior, preventing it from contracting. The interior is therefore under a tension force which is attempting to expand its volume.

  2. Pyros says:

    Strange to say, I’ve known people with personalities exactly life that drop of glass.

  3. Gemini Gypsy says:

    Very, very cool.

    I feel like that sometimes.

  4. umgrego2 says:

    These Prince Rupert’s pieces of glass played a role in the movie Oscar and Lucinda with Cate Blanchett and Ralph Fiennes; powerful movie.

  5. johnrynne says:

    Pity you can’t actually see the “blows up into billions of tiny pieces” thing because of the glare on the water’s surface. We’ll have to take their word for it.

  6. Beanolini says:

    #3: And also the Peter Carey novel the film was based on.

    Prince Rupert himself was a particularly colourful character- a flamboyant mercenary, who used to go into battle with a white poodle (accused of being his magical familiar, and sexual partner). He apparently survived a shot to the head, and two trepannings, and retired from warfare to pursue scientific research.

  7. Luc says:

    #4, you can see some drops explode here:

  8. Kit10inDublin says:

    #29 – Thanks BEANOLINI. I was about to post an answer #3 UMGREG02 that Oscar & Lucinda is actually based on Peter Carey’s superb novel.

    If you’ve read the book you’d be disappointed by the film. Carey’s description of the Prince Rupert Drop is so much more powerful than the subsequent visual depiction.

  9. chgoliz says:

    #5, thanks for that link.

    I was wondering if the reason they did it in the bucket of water was to avoid microscopic shrapnel. Based on the second video, I’d say that was it. Any exposed skin would get hit pretty bad.

  10. TulsaTV says:

    Prince Rupert Drops are mentioned in the classic SF story, “Dune Roller” by Julian May. The story was dramatized on “Tales of Tomorrow”, an early TV series available on Netflix or Amazon (Tales of Tomorrow, Collection 2.) The story is stylish and effective, the TV adaptation, not so much.

  11. McGrude says:

    #7, yes the thought of doing this without eye protection make me cringe.

  12. padster123 says:

    Can you do it with drops of molten sugar?
    Instant icing sugar!

  13. David Carroll says:

    PseudoThink: (#18)

    While I am sure the Casio EX-F1 is a fine camera, I don’t think 60 FPS is going to cut it.

    I was thinking along the lines of:

    This camera can record 100,000 FPS. I wonder if they rent?

  14. BobbyMike says:

    A well known prank in the glassblowing world is to slip one of these into someones back pocket and “pop” it. Loads of fun!

  15. morehumanthanhuman says:

    It’s even more curious that they can occur naturally:

  16. Takuan says:

    so molten glass entrained with toxin could be smuggled in as jewelery and released on target

  17. vjinterkosmos says:

    #13, #18: Been done, apparently. Alas, the video was not to be found on the interweb.

    “Recently an examination of the shattering of Prince Rupert’s Drops by the use of extremely high speed video (or so called “stop motion” techniques) [1] done by Dr. Srinivasan Chandrasekar at Purdue University has revealed that the “crack front” which is initiated at the tail end, propagates in a disintegrating drop within the tensile zone towards the drop’s head at a very high velocity (~ 1450-1900 m/s, or up to ~4,200 miles per hour).”


  18. gregger says:

    Yes, but Will it Blend?

  19. Chocolatey Shatner says:

    Thank you: I love science!

  20. Antinous says:

    Is Prince Rupert’s drop related to Prince Albert’s ring?

  21. Adam Stanhope says:

    The Corning Museum of Glass in Corning, New York is one of the best museums I’ve ever been to. Anyone interested in glass technology or glass history will love it. I visited in summer of 2006 and enjoyed it more than any other museum visit I’ve had anywhere.

  22. David Carroll says:

    Does anybody have a high speed camera I can borrow for a 1/100 of a second? Oh and $200,000 so I can film it in zero G.

  23. bogartnoir says:

    I learned about Prince Rupert’s Drops from The Cure’s Robert Smith when I was 14.
    It’s been one of my favorite scientificals ever since.

  24. Patrick Dodds says:

    But who was Rupert?

  25. Joel Schlosberg says:

    A Prince Rupert’s drop also plays a role in Fritz Leiber’s novel Conjure Wife.

  26. Mr. Protocol says:

    I could be wrong but I think it has to be a bucket of oil, not water. So I was told by the guy who was making these at a fair.

  27. stoo says:

    The guy in that video is just being a pansy. You can just hold prince ruperts drops in your hand and snap them. The dust is so fine that it won’t cut you or anything.
    These drops are basically like tempered glass but with a much steeper residual stress gradient from inside to out.

  28. Jim Richardson says:

    The video said the interior was in tension and the exterior was in compression.

    Is that correct? Wouldn’t the interior be in compression and the exterior be in tension because the exterior cooled first and presumably shrank and created tension, that compressed the core.

    I may be wrong. I know water expands on freezing but I thought it was unusual in that regard.

    richardsonjim (AT)

  29. Antinous says:

    But who was Rupert?

    Prince Rupert of the Rhine, Count Palatine and Duke of Bavaria, grandson of James I & VI, son of Elizabeth of Bohemia, the Winter Queen, and brother of Sophia, Electress of Hanover. He’s buried in the same vault as Mary Queen of Scots, Queen Anne’s 18 stillborn babies and a host of other tragico-romantic roadkill of the Tudor/Stuart era.

  30. Evil Jim says:

    So in the end Prince Rupert was just this really tense, fragile guy.

  31. Takuan says:

    also responsible for the REALLY unmentionable body piercing – not like his vanilla brother, Albert

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