Have you ever ripped a strip of packing tape off a box and winced at that awful screech? We all have. It's one of those sounds that gets under your skin — sharp, jarring, oddly aggressive for something so ordinary. But here's a question that might stop you in your tracks: what if that annoying noise is actually a rapid-fire train of tiny sonic booms?

Welcome to FreeAstroScience, where we take the most surprising corners of science and break them down so everyone can enjoy the ride. Today we're looking at a brand-new study, published on 24 February 2026 in Physical Review E, that finally answers a question physicists have been scratching their heads over for decades: Where does the screeching sound of peeling tape actually come from?

The answer is wild. It involves supersonic fractures, miniature vacuum pockets, and shock waves that travel faster than sound — all happening beneath a piece of everyday Scotch tape. Stay with us to the very end, because this story will change the way you hear that ripping sound forever.

Tiny Sonic Booms: Why Peeling Tape Screams at You

Think of a fighter jet punching through the sound barrier. The air can't move out of the way fast enough. A shockwave rolls across the sky, and you hear a sharp crack — the sonic boom.

Now picture the same idea, but shrunk down to a strip of adhesive barely 19 millimeters wide. That's what a team led by Er Qiang Li and Sigurdur T. Thoroddsen at King Abdullah University of Science and Technology (KAUST) in Saudi Arabia discovered. When we peel tape from a surface, microscopic fractures race across the adhesive faster than the speed of sound in air. And each one, upon reaching the tape's edge, fires off its own miniature shock wave. [[1]]

The screech you hear? It's dozens upon dozens of those tiny shocks hitting your eardrums in rapid succession — a machine-gun burst of sonic booms so small you could fit thousands of them on your thumbnail. [[2]]

What Happens When You Rip Tape? The Stick-Slip Dance

Tape doesn't peel smoothly. Not even close.

If you could watch the process in extreme slow motion, you'd see something that looks almost like breathing. The adhesive grips the surface (stick), then suddenly lets go in a quick burst (slip). It repeats this over and over — stick, slip, stick, slip — sometimes hundreds of times per second. Physicists call this stick-slip dynamics, and the same mechanism appears in earthquake faults along tectonic plates. [[1]]

During each slip phase, something remarkable happens beneath the tape. A rapid sequence of transverse fractures — tiny cracks running sideways across the adhesive — shoots from one edge of the tape to the other. Each fracture band is only about 220 micrometers wide, roughly twice the thickness of a human hair.

These fractures aren't gentle. They tear through the adhesive at speeds between 250 and 600 meters per second. For context, the speed of sound in air at room temperature (20 °C) is about 342 m/s. Many of these cracks are literally outrunning sound.

A Quick Sense of Scale

Each slip phase lasts about 0.5 milliseconds — half a thousandth of a second. In that flicker of time, a sound wave can travel only about 17 centimeters. Everything we're discussing happens in a space smaller than a credit card and a timeframe too short for your eye to register.

How Did Scientists Catch Shock Waves from Tape?

This is where the experiment gets beautiful. The KAUST team built a setup that reads like a wish list for any physics lab:

Two ultra-high-speed cameras. One, a Kirana-05M, recorded at up to 2,000,000 frames per second with a 100-nanosecond laser pulse exposure. The other, a Phantom V2512, filmed through the bottom of a glass plate to track the fractures.
A schlieren imaging system — a classic optical technique that reveals changes in air density. Two large concave mirrors and a horizontal knife-edge allowed the team to see the pressure waves rippling through the air beside the tape.
Two high-definition microphones (Earthworks M30), one placed on each side of the tape, sampling at 192 kHz — more than six times the standard audio rate. [[1]]

They peeled 19-mm-wide Scotch tape off a thick glass plate at roughly 45° and let all four sensors record at the same time. Everything was synchronized to the microsecond. [[1]]

The result? They could match each individual fracture — visible through the glass — with the exact sound pulse picked up by the microphones and the exact shock front captured in the schlieren video. No guesswork. Pure, frame-by-frame proof.

Where Does the Sound Actually Come From?

Here's the twist that surprised even the researchers.

The original hypothesis was intuitive: because the fracture tip moves supersonically through the adhesive, it should send shock waves outward from its moving tip — like the bow wave of a speedboat. If that were true, the microphone closer to where the crack starts would pick up the sound first.

They saw the exact opposite.

The microphone closer to where the crack ends — at the far edge of the tape — detected the pulse first. And not just slightly first. The sound signal was 1.9 times more intense on that side, even though the distances were nearly equal.

The schlieren video confirmed it beautifully. Four distinct, semicircular shock fronts appeared marching away from the exit edge of the tape, and between them — nothing. No density fluctuations at all. No shock waves emerged from the opposite side during a typical run. [[1]]

So the sound isn't born from the moving tip. It's born at the moment the fracture punches through the tape's edge and slams into the still air outside. [[1]] [[2]]

How Does a Tiny Vacuum Create a Sonic Boom?

This is the part we find most elegant. Let's walk through it slowly.

When a fracture rips across the adhesive, it opens a sliver of empty space between the tape and the glass. Because the crack moves faster than sound, the surrounding air simply can't rush in fast enough to fill the gap. A partial vacuum forms — a pocket of near-nothingness — and it rides along with the advancing crack tip like a shadow.

That tiny void survives the full journey across the tape. But the instant the crack reaches the edge, there's no more adhesive to sustain it. The vacuum meets the open atmosphere and collapses violently. Air slams into the void at the speed of sound, generating a sharp, sudden pressure pulse — a weak shock wave.

The researchers measured these shocks traveling at 355 ± 2 m/s, which is Mach 1.04 — 4% above the speed of sound.

Repeat this process for every fracture in every slip phase, dozens of times per millisecond, and what you hear is the tape's characteristic screech. It's not one sound. It's a train of miniature sonic booms, each lasting less than a microsecond, arriving so fast your brain blends them into a single, irritating shriek.

As Geopop's Filippo Bonaventura put it: "The screeching of adhesive tape is, in every respect, a train of sonic booms conceptually not so different from those produced by aircraft breaking the sound barrier."

The Numbers Behind the Noise

We know many of our readers love data. Let's gather the key figures from the study into a clear picture.

Key Physical Parameters — Screeching Sound of Peeling Tape
Parameter	Value	Notes
Tape width	19 mm	Standard Scotch tape
Fracture band width	≈ 220 μm	About 2× a human hair
Fracture speed range	250 – 600 m/s	Mach 0.7 – 1.8 in air
Speed of sound (air, 20 °C)	342 m/s	Reference baseline
Measured shock speed	355 ± 2 m/s	Mach 1.04 (4% above sound)
Slip-phase duration	≈ 0.5 ms	Contains dozens of fractures
Void closure time	≈ 0.6 μs	Extremely rapid collapse
Dynamic pressure at source	≈ 9,600 Pa	ρ c Δv estimate
Shock frequency (example)	≈ 37 kHz	Beyond human hearing threshold
Camera frame rate (max)	2 × 10⁶ fps	Kirana-05M, 100 ns laser pulses
Peeling angle	45° ± 2°	Guided by a metal rod

The Key Formulas

For those who enjoy the math, let's look at the central relationships the team used to explain the shock generation.

1. Dynamic Pressure of Collapsing Void

p_dynamic = ρ · c · Δv

Where ρ is the air density, c is the speed of sound (342 m/s), and Δv is the velocity of air rushing into the void (≈ mean fracture speed in the slip phase). This yields roughly 9,600 Pa — a forceful pressure spike from a gap barely 200 μm tall. [[1]]

2. Void Closure Time

t_c = h / c ≈ 0.6 μs

Where h ≈ 200 μm is the height of the void and c = 342 m/s. The gap slams shut in about 0.6 microseconds — so fast that the pressure change is essentially instantaneous, producing the sharp pulse we hear as a shock.

3. Pressure Decay with Distance

p ∝ 1 / r

As the spherical shock front expands, pressure drops inversely with distance r. Extrapolating the measured pressures back to an impulse dimension of about 1 μm, the team estimated source pressures as high as 5,000 Pa — consistent with their dynamic-pressure calculation. The energy flux scales as p² ∝ 1/r², so intensity falls off quickly. [[1]]

Notice how everything fits together: an impossibly narrow crack, an impossibly brief vacuum, an impossibly fast collapse — all conspiring to produce a perfectly audible (and perfectly annoying) sound.

Why Should We Care About Peeling Tape Physics?

You might wonder: all this effort for the sound of tape? Is it really worth two million frames per second and a room full of mirrors?

The answer is yes — and the reasons stretch far beyond your packing supplies.

Fracture mechanics is at the heart of how materials fail. Engineers use the same stick-slip models to predict when bridges crack, when airplane fuselages fatigue, and when geological faults release energy as earthquakes. The adhesive under a strip of Scotch tape is a simple, safe, tabletop laboratory for studying these processes.

There's also the phenomenon of triboluminescence — light emission from friction and fracture. When tape is peeled in a vacuum, the same supersonic fractures can generate x-rays. Yes, x-rays from tape. Camara et al. demonstrated this in a 2008 Nature paper. [[1]] Understanding the mechanics of the fracture tips matters if we ever want to harness that energy.

And at a more fundamental level, this study corrects a decades-old assumption. Before Thoroddsen et al. revealed the transverse fractures in 2010, physicists were modeling tape-peeling dynamics in the wrong physical dimension — thinking the slip traveled along the pulling direction, not sideways across the adhesive. Science sometimes needs a camera fast enough to see its own blind spots.

Conclusion: An Everyday Act, an Extraordinary Physics Lesson

Let's recap what we've learned.

The screeching sound of peeling tape isn't caused by the vibration of the tape ribbon, or by air escaping a gap, or by any single wave bouncing off a surface. It's a train of weak shock waves, each generated at the precise moment a supersonic fracture in the adhesive punches through the tape's edge and its accompanying micro-vacuum collapses against the open air.

These shocks travel at Mach 1.04 — just over the speed of sound — and arrive at your ears in such rapid succession that your brain blends them into a single, unmistakable screech. The entire drama plays out across a 19-mm stage in half a millisecond, at velocities up to 600 m/s, with pressures near the source touching thousands of pascals.

It's a humbling reminder that extraordinary physics doesn't require a particle accelerator or a deep-space telescope. Sometimes it's right there on the kitchen counter, hidden inside a roll of Scotch tape.

We think there's something comforting in that. You don't have to go far to find wonder. You don't need a PhD to be astonished. The next time you seal a box and hear that familiar shriek, smile — you'll know you're listening to a train of sonic booms, born from fractures thinner than a hair, in a void that lasts barely half a microsecond.

At FreeAstroScience.com, we believe in explaining complex scientific ideas in plain, honest language — because the sleep of reason breeds monsters. Keep your mind active. Keep asking why. Come back any time you want to sharpen your curiosity; we'll always have something new waiting for you.

Sources

Er Qiang Li, Paul W. Riker, Sriram Rengarajan, Zi Qiang Yang, Kenneth R. Langley, Ravi Samtaney, and Sigurdur T. Thoroddsen, "Screeching sound of peeling tape," Physical Review E 113, 025508 (2026). DOI: 10.1103/p19h-9ysx
Filippo Bonaventura, "Il rumore stridente del nastro adesivo che si stacca è causato da onde d'urto supersoniche: lo studio," Geopop, 26 February 2026. geopop.it

Hate Tape Screech? Are You Hearing Tiny Sonic Booms?

Tiny Sonic Booms: Why Peeling Tape Screams at You