Tearing tape off the roll can be a satisfying way to entertain yourself in the office. But you're not just wasting office supplies — according to new scientific studies, that tape is also emitting X-rays and ultrasonic sounds.
Though you might not guess this from experience, peeling adhesive is actually a version of fracturing. It's a physical process that's related to more obvious types of fracturing like cracking a rock open. Viewed in this way, it becomes a bit more believable that peeling tape releases X-rays. After all, a fragmenting rock can sometimes release sparks.
A few years ago, researchers discovered the X-rays emitted by peeling adhesive tape in vacuum, by recording the process in the lab. You can see what they found in this video.
Today in Nature, another team of scientists reveal that the "screeching" sound of tape peeling is actually quite complex. Much of the sound is in the above-audible range for humans. I love this illustration of how they staged the experiment, to record tape ripping.
Write the researchers:
We investigate the generation of the screeching sound commonly heard during tape peeling using synchronised high-speed video and audio acquisition. We determine the peak frequencies in the audio spectrum and, in addition to a peak frequency at the upper end of the audible range (around 20 kHz), we find an unexpected strong sound with a high-frequency far above the audible range, typically around 50 kHz. Using the corresponding video data, the origins of the key frequencies are confirmed as being due to the substructure "fracture" bands, which we herein observe in both high-speed continuous peeling motions and in the slip phases for stick-slip peeling motions.
So when you're yanking tape off the spool, you're actually throwing off highly energetic particles and ultrasonic noises. The whole process winds up being about as violent as it sounds.
Read the whole paper over at Nature.