Category: Photography & Images

Mary found a sliver chipped from the outside edge of a Corelle dinner plate, which provides an opportunity to see something that’s normally invisible: the ceramic layer inside its glass coating.

Overall, the sliver is nearly two inches long and about the same width as the plate is thick.

Peering through the microscope at the left end, the glass layer is most obvious along the top edge. You can barely see it along the bottom, where the chip thins to a razor edge.

On the right end the upper and lower glass layers are a bit more obvious, at least with the light arriving nearly horizontally and after some aggressive exposure hackage,

The ceramic has a slightly higher coefficient of thermal expansion than the glass, so it puts the glass under a tremendous amount of compressive stress as the newly manufactured plate cools. Glass is really strong in compression (and terribly weak in tension), so the plate becomes remarkably hard to break. More details there and there.

The plate rims do tend to chip, however, if you own them as long as we have. These are the long-discontinued Old Town Blue pattern: over three decades old by now.

Oddly, they’re still under warranty: back in the day, Corning sold its then-new Corelle with a Lifetime Warranty. Nowadays, you get three years for the mid-grade line, five years for thicker plates, and a mere one year for stoneware (whatever that is). I suppose enough people actually took them up on the warranty to make it economically impractical.

I ran a fine diamond file over the chipped edge and it’s OK. Eventually, we’ll break down and get new plates, but there’s no sense rushing a decision like that…

Our daughter snagged some tchotchkes from a high-school career fair, including one that she instantly recognized as a flamethrower: Antibacterial Hand Sanitizer Spray, 62% Ethyl Alcohol plus some other junk, in a handy pump-spray container. Heck, it even says

Warnings Flammable. Keep away from open flame. Keep out of reach of children.

I was so proud of her…

After homework, she stuck a candle atop the garbage can by the garage and fired off a few shots while I ran the camera. Here’s the best one, converted to a low-speed animated GIF.

We’re pretty sure that’s Sweet Babby Jeebus™ in the next-to-last frame of the flare. Maybe Madonna. Could go either way.

Much as with the “movies” I made for trebuchets and tree frogs, I used ffmpeg to shred the camera’s mpg movie into separate jpg images, some bash to select the frames, then convert to stitch them back together into a gif.

The general outline:

mkdir Frames
ffmpeg -i mov04990.mpg -f image2 Frames/frame-%03d.jpg
cd Frames
mkdir flare3
for f in `seq 760 780` ; do cp frame-${f}.jpg flare3 ; done
cd flare3
convert -delay 50 frame-* Flare3.gif

If my bash-fu was stronger, I could feed the proper file names directly into convert without the copy step.

Now, kids, don’t try this at home. At least not without responsible adult supervision…