---
title: "Jazz solo played into a Rubens tube turns sound waves into dancing flames in a viral Reddit clip"
url: https://badiyaa.com/rubens-tube-jazz-solo-flames/
published: 2026-11-10T10:15:00+00:00
modified: 2026-11-10T10:15:00+00:00
section: Offbeat
publisher: Badiyaa
---

# Jazz solo played into a Rubens tube turns sound waves into dancing flames in a viral Reddit clip

A viral Reddit clip credited to musician Moises Alves shows a jazz solo played into a Rubens tube, the 1905 flame pipe that makes sound visible.

A horn player blows a jazz solo into one end of a perforated metal pipe, and a row of gas flames along the top jumps and sinks in time with every phrase. The clip, posted to Reddit’s r/nextfuckinglevel this week, credits the musician as Moises Alves and calls the pipe what physics teachers have called it for more than a century: a Rubens tube.

Viewers reacted to the science first. “Sound is so much more physical than we usually realise,” one commenter wrote. Another identified the horn as a trumpet with a copper bell. A third spotted what appeared to be gas cans near the open flames in the final seconds, and several begged the camera operator to stop moving.

## How a pipe of fire shows sound

The device is simple. A length of pipe is drilled with a line of small holes, sealed at both ends, and filled with a flammable gas such as propane. One end carries a speaker or other sound source. The gas escaping through the holes is lit, giving a neat fence of small flames.

When sound enters, pressure inside the pipe starts to vary from point to point. With a steady tone at the right pitch, a standing wave forms. At some spots the pressure swings hard back and forth; at others it barely moves. Gas flow through each hole depends on the square root of the pressure difference, so where the pressure oscillates, less gas escapes on average and the flames shrink. Where it holds steady, they stand tall. The result is a wave you can see, and with a ruler you can measure its wavelength straight off the flames.

A jazz solo is not a steady tone. Pitch and loudness change from note to note, so the pattern never settles for long. That is why the flames in the clip ripple and flicker rather than freezing into the tidy peaks of a classroom demo.

## A 1905 invention from Berlin

The tube is named after Heinrich Rubens, a German physicist born in 1865 who worked at the University of Berlin alongside Max Planck on groundwork for quantum physics. He demonstrated his flame tube in 1905. The original was a four-meter pipe with roughly 100 holes, each 2 millimeters across.

Divide the four meters by 100 holes and the flames sat about 4 centimeters apart, close enough to trace a smooth wave. The longest Rubens tube on record is far bigger: Estonian science show Kvark built a 10-meter version at Saku Suurhall in 2019, two and a half times the length of the original.

The idea has also spread sideways. A flat version called a pyro board turns a steel box into a grid of burners, so sound draws patterns in two dimensions. Danish demonstration group Fysikshow made it famous.

## Why it keeps going viral

Physics departments, science centers and touring science shows still wheel the tube out because it turns something invisible into fire. Edmonton’s science center used one to win a Canadian science-center competition filmed in 2010, and artist Emer O’Brien built a sound sculpture around Rubens tubes for a 2012 London exhibition.

Waves of other kinds draw the same fascination. Badiyaa has covered a [Danish wave energy machine that folds shut in storms](https://badiyaa.com/weptos-v-shaped-wave-energy-converter/), and the German lab story of how [Wilhelm Röntgen spotted X-rays in 1895](https://badiyaa.com/wilhelm-rontgen-x-rays-november-8-1895/), a decade before Rubens lit his pipe. For more brass on show, see how [FAMU’s Marching 100 took over a halftime show in Mississippi](https://badiyaa.com/famu-marching-100-jackson-state-halftime/).

Anyone tempted to copy Alves should note what the device is: an open line of flames fed by pressurized gas. Classroom versions run under supervision, and the original design used just 2-millimeter holes along a sealed four-meter pipe.

## Further reading

- [Wikipedia: Rubens tube](https://en.wikipedia.org/wiki/Rubens_tube)

*Illustrative image. Image: Pete from Liverpool, UK, CC BY 2.0 via Wikimedia Commons*

*This article was produced with AI assistance and reviewed by our Editorial Desk. [How we work](https://badiyaa.com/editorial-policy/).*