The other day, I was headed to the back patio to smoke and contemplate writing more incredible content for you, dear reader, here on the blog.  Nothing helps that process along like a nice cold glass of Coca-Cola. So I fetched one.  Glass, ice, Coke.

As I opened the sliding glass door, without knocking the glass against anything or any other trauma to the glass, it split perfectly in two. Sending Coke and ice all over the place. Very weird. I guess there was a flaw in the glass or something.


Obviously, I should have used a blue Solo cup (red is for booze only).

16 thoughts on “Weird.”

  1. Wow. Must have been a flaw in it that the cold ice triggered in a glass that was warm. Now I’m glad that our beer mugs sit in the freezer waiting for cold beer and avoiding such a temperature shift. I’d hate to lose beer that way.

    1. That was my first thought as well, but the parting line should have been at the outside of the rim of the glass. I don’t see anything that would require a 3-piece mold on this … It should just be a core (to form the inside) and a cavity (to form the outside).

      Very odd.

    1. Is Sox part of the Alan Parsons Project? Best to start searching for one million dollars.

  2. I’ve heard of something similar happening before. A friend had a glass burst while it was sitting in a cabinet. I remember looking up why it happens but don’t recall exactly what i found except that it is apparently a somewhat frequent occurrence.

    1. I think it’s caused by residual stresses from casting the glass form. Thicker glass utensils seem to be the most common in these incidents.

  3. I’ve worked as a cook a long time, and I’ve seen that before, but not in a while. Usually it happens when someone takes a glass right out of the dishwasher, and dumps ice & cold soda in.

    I’m guessing it’s caused by the inside of the glass shrinking slightly in reaction to the cold, while the outside was unaffected.

    QM, I’ve never thought about it before, but I don’t recall seeing that happen to thinner glasses like wine glasses. On the other hand, most places hand-wash the bar glasses anyway, as opposed to running the soft drink glasses through the dishwasher.

    I’m just glad our host didn’t get sliced up. 🙂

    1. A lot of people are not aware of residual stress and what it can do. A lot of pain is taken to minimize residual stresses in structural steel. Stress is stress and steel frames have been known to collapse during erection from residual and erection stresses (which can actually exceed design stress). In Jeff’s reactor vessel construction, as he mentions below, they have to worry about unpredictable stresses being built up during service, particularly start up and shut down (residual stresses are induced by nonuniform heating and cooling). That thing might be a goram pussycat under normal circumstances, but anytime you have materials with large thermal gradients in them, you are playing with fire simply because of the physics of materials science. You allow for it, or it bites you quite painfully on the tush. The effects would be far worse than all those free neutrons he absorbed down in the hole

  4. I’ve seen lots of heavier glass tumblers that have a mold line running vertically on the outside of the glass, 180 degrees apart. But yours didn’t split totally even, it looks like.
    As others have chimed in, probably thermal differential caused by the cold soda and an invisible flaw in the tumbler.
    My $0.02 to the mystery.

  5. Brittle Fracture: Sudden, catastrophic failure with little to no plastic deformation. Requirements: Low fracture toughness (basically easy to break, glass definitely fits), preexisting flaw, and tensile stress (Casey is right, on cooldown the colder inner wall experiences tensile stress as it is “pulled apart” by the warmer outer wall). See: SS Schenectady.

    Quite a lot of skull sweat is expended in keeping that from happening to reactor pressure vessels.

    Something similar happened at my brother’s graduation. We were at the bar waiting for a table, we clinked our glasses in celebration and the bottom of my brother’s mug fell off.

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