Best examples of exploring resonance with a wine glass in real experiments

Hands-on examples of exploring resonance with a wine glass

Before we talk theory, let’s start with concrete experiments. The most useful examples of exploring resonance with a wine glass are the ones you can repeat, measure, and compare.

A wine glass is a classic resonator: it has a natural frequency (or several) at which it prefers to vibrate. When you drive it with sound or friction at or near that frequency, the vibration amplitude can grow dramatically. The following examples include simple classroom setups and more advanced measurements that mirror what researchers do in acoustic labs.

Classic example of a “singing” wine glass (rubbing the rim)

One of the best examples of exploring resonance with a wine glass is the familiar “singing glass” demonstration. You lightly wet your finger, press it against the rim, and slide around the circumference. The glass suddenly starts to sing with a clear, sustained tone.

What’s going on:

• Your finger sticks and slips against the glass surface, providing a periodic driving force.
• If that driving matches one of the glass’s natural frequencies, the rim vibrates strongly.
• The vibrating rim pushes on the surrounding air, producing the audible tone.

Why this is such a strong example of resonance:

• The pitch is stable and easy to hear.
• Small changes in water level shift the pitch, so you can show how mass and stiffness control resonant frequency.
• It scales: students can try it with different glasses and compare results.

If you record the tone with a laptop microphone and analyze it with free software like Audacity or a phone spectrum app, you can estimate the resonant frequency to within a few hertz. That turns this into a real, data-driven acoustics experiment.

Examples of frequency shifts: filling the glass with water

Once you have the glass singing, one of the cleanest examples of exploring resonance with a wine glass is to track how the frequency changes as you add water.

Here’s a simple procedure:

• Start with an empty wine glass and get a stable singing tone.
• Record a short clip and measure its frequency with a spectrum tool.
• Add a small, measured volume of water (say 1 ounce at a time) and repeat.

What you’ll notice:

• As the water level rises, the pitch drops.
• The added water increases the effective mass and changes how the glass vibrates.

This gives you a set of real examples you can graph: water height versus frequency. The curve is not perfectly linear, but students can see a clear downward trend. Many introductory physics labs use nearly identical setups to discuss resonance and oscillations; the American Association of Physics Teachers has published similar activities in The Physics Teacher journal (see the American Association of Physics Teachers for teaching resources).

You can also compare different glass shapes:

• Tall, thin wine glass
• Short, wide goblet
• Heavy crystal vs. thin glass

These real examples show how geometry and material change the resonant behavior.

Tapping the glass: impulse response as another example of resonance

Rubbing the rim is a continuous drive. Tapping the glass is a short impulse, but it still reveals resonance beautifully.

Try this:

• Hold the stem lightly so you don’t damp the motion too much.
• Tap the rim gently with a fingernail or a wooden chopstick.
• Record the sound and zoom in on the waveform.

What you’ll hear is a bright “ping” that quickly decays. That ring-down is the glass vibrating at its natural frequency. The tap excites many modes at once, but the strongest resonant modes dominate the sound you hear.

This is one of the simplest examples of exploring resonance with a wine glass that connects directly to engineering practice. Mechanical and civil engineers study similar ring-downs to evaluate material properties and damping in structures. The National Institute of Standards and Technology (NIST) discusses related vibration testing methods in its metrology work (NIST.gov).

You can extend this example:

• Compare the decay time with and without your hand gripping the bowl.
• Add a rubber band around the rim and see how much faster the sound dies out.

Students immediately see how damping controls how long resonance persists.

Driving the glass with a speaker: matching the resonant frequency

For a more controlled example of exploring resonance with a wine glass, replace your finger with a speaker and a tone generator.

Setup:

• Place a wine glass a few inches in front of a small speaker.
• Use a signal generator app or software to sweep through frequencies (for example, 300–2000 Hz).
• Gradually increase volume while sweeping the frequency.

What to look for:

• At most frequencies, the glass barely responds.
• Near its resonant frequency, the rim visibly vibrates, and the sound gets louder and more focused.

This gives you a clean, textbook example of resonance: small input, big response at the right frequency. With a phone camera in slow-motion mode, you can sometimes see the rim oscillating, especially if you place a small piece of reflective tape on the rim and watch its motion.

Educators often pair this with a discussion of resonance in bridges and buildings. The U.S. Geological Survey, for example, explains how structures have natural frequencies that can be excited by earthquakes and wind (USGS.gov). The wine glass is a safe, small-scale analog.

Famous “shattering glass” demo: high-amplitude resonance

One of the most dramatic examples of exploring resonance with a wine glass is the classic “shatter a glass with sound” demonstration. Popularized by TV shows and viral videos, it looks like magic, but it’s just resonance plus high sound intensity.

Key ideas:

• Every glass has a resonant frequency where it vibrates strongly.
• If you drive it at that frequency with enough acoustic power, the stress in the glass can exceed its strength.

In controlled lab or stage setups, experimenters:

• First measure the glass’s resonant frequency by tapping it and analyzing the sound.
• Use a powerful speaker and amplifier to play a pure tone at that frequency.
• Slowly ramp up the volume until the glass fails.

This is not a beginner home experiment because of the sound levels involved. Sound intensities high enough to break glass can damage hearing. If you discuss this in class, it’s worth mentioning safe listening levels and pointing students to hearing health resources from the National Institutes of Health (NIH.gov).

Even without actually breaking the glass, you can still create a safe version of this example by:

• Driving the glass near its resonant frequency.
• Filming the motion in slow motion.
• Observing how the amplitude grows as you approach the natural frequency.

It’s a powerful visual example of how resonance can magnify motion.

Examples of comparing different materials and glass designs

Not all wine glasses resonate the same way. Some of the best examples of exploring resonance with a wine glass come from systematic comparisons:

• Thin-walled vs. thick-walled glass
• Regular soda-lime glass vs. lead crystal
• Long-stemmed vs. stemless designs

In a classroom or lab, you can:

• Use the rubbing or tapping method to find the dominant frequency of each glass.
• Record and measure those frequencies.
• Note the subjective loudness and decay time.

Patterns you’ll usually see:

• Thinner glasses often have higher, clearer pitches and ring longer.
• Heavier, thicker glasses tend to have lower, duller tones and stronger damping.

These real examples help students connect material properties (density, stiffness, internal friction) with acoustic behavior. Universities commonly use similar comparisons in introductory acoustics courses; for deeper background, many instructors point to open course materials from institutions like MIT and Harvard (for example, Harvard’s physics resources).

You can push this further by measuring:

• Temperature effects: does the pitch change if the glass is chilled vs. warm?
• Liquid effects: water vs. wine vs. oil, each with different density and viscosity.

Those variations create a whole family of examples of exploring resonance with a wine glass that can keep an advanced high school or early college lab busy for several sessions.

Using smartphone apps: modern examples with 2024–2025 tools

One trend that has really matured by 2024–2025 is the use of smartphones as portable acoustic labs. That gives you fresh, modern examples of exploring resonance with a wine glass using tools students already carry.

Typical workflow:

• Install a free spectrum analyzer or frequency meter app.
• Rub or tap the wine glass and watch the live spectrum.
• Identify the peak frequency and note its value.

You can then:

• Track how the peak moves as you add liquid.
• Compare different glasses and export the data.

Some apps also show spectrograms, so you can visualize how the frequency content changes over time as the glass rings down. That’s a nice bridge to more advanced signal analysis used in acoustics research and audio engineering.

Educators increasingly integrate these smartphone-based examples into inquiry-based labs and science fair projects. The technology lowers the barrier to doing real measurements, not just qualitative demos.

Classroom and lab-friendly examples of structured experiments

If you’re designing a formal experiment, you can combine several of these ideas into a single, coherent lab. Here are examples of how teachers and students often organize a sequence of exploring resonance with a wine glass:

• Start with tapping each glass to find and record its natural frequency.
• Use a smartphone app to measure those frequencies and build a small dataset.
• Move to the rubbing technique to explore continuous resonance and observe how easy it is to sustain the vibration.
• Add water in controlled steps, measuring the frequency at each level.
• Conclude with a speaker-driven experiment to show that the same frequencies appear when you drive the glass externally.

The result is a set of linked experiments that all point back to the same underlying physics: systems have preferred modes of vibration, and when you drive them at those modes, you get resonance.

These structured examples of exploring resonance with a wine glass also make strong science fair projects. Students can pose questions like:

• How does glass thickness affect resonant frequency and decay time?
• How does liquid density influence the pitch of a singing glass?
• Can we model the glass as a simple harmonic oscillator and match the data?

Because the apparatus is inexpensive and the measurements are repeatable, wine glasses are surprisingly good platforms for serious acoustic investigation.

FAQ: common questions about wine glass resonance experiments

Q: What are some easy examples of exploring resonance with a wine glass for beginners?
Simple examples include tapping the rim and listening to the ring, rubbing the rim to make the glass sing, and adding water to hear the pitch drop. All three can be done safely at home or in a classroom with no special equipment.

Q: Can you really break a wine glass with sound, or is that just a TV trick?
It’s real, but it requires a carefully matched resonant frequency and very high sound levels from a strong speaker and amplifier. Because those sound levels can be hazardous to hearing, this is not recommended as a casual home experiment.

Q: Which type of wine glass gives the best examples of resonance?
Thin, clear glasses with a long stem and smooth rim usually produce the cleanest, loudest tones. They make an excellent example of a lightly damped resonator, which is ideal for teaching.

Q: Is there a safe example of using technology to study wine glass resonance?
Yes. Using a smartphone spectrum analyzer app to measure the frequency while you tap or rub the glass is both safe and informative. You get quantitative data without needing lab-grade instruments.

Q: How does this relate to real-world engineering examples of resonance?
The same principles show up in bridges, skyscrapers, car suspensions, and even musical instruments. Engineers analyze natural frequencies and damping to avoid destructive resonance in structures, similar to how a glass can shatter if driven too strongly at its resonant frequency.

By building a set of clear, repeatable examples of exploring resonance with a wine glass—from simple tapping to smartphone-based measurements—you get a compact, powerful toolkit for teaching and learning acoustics. The physics is the same as in large-scale engineering problems; the only difference is that here, the resonator happens to sit on your dinner table.