History and Original Composition
Explanation: How it Works
Theory
Ruben’s Tube Risks and Safety Measures
Ruben’s Tube Applications
Then, a loudspeaker was attached to one end of the device and sound was played into it when the heights of the flames changed depicting pressure differences set up within the tube due to the sound waves. In 1866, another scientist by the name of August Kundt gave a similar demonstration of standing waves in the Ruben’s tube by placing sawdust in it. When a varying sound was played through it, the dust lined up showing node and antinode formation. Behn also claimed later that the flames used in this device can be used as indicators of pressure differences. Since the Ruben’s tube is closed at one end, standing waves of sound are setup inside. According to Bernoulli’s Principle, the speed with which the gas comes out of the setup is a function of the pressure difference between the interior of the tube and the atmospheric pressure. Hence, at places of high-pressure differences the gas escapes out with high velocity and the flames shoot up. And, the places in the apparatus where the pressure differences are low, are characterized by short flame heights. The points of maximum pressure have the tallest flame and are known as crests. On the other hand, the points of minimum pressure having the shortest flames are known as troughs.
Knowing the values of f and λ, the velocity of sound in the gas can be determined. Many musicians and bands make the flames dance to their music for giving a unique audio-visual treat to their audience. Instead of a pipe, some use a cuboid that offers a larger surface area for the holes. This arrangement, known as Pyro Board is an improvisation of the classical structure of the tube and gives a 2D effect of the flames. Singing stars have created a sensation by performing on themes like dubstep and Gangnam Style on the structure. Although the device has only antique value now, it is one of those rare inventions of Physics which allows learners to grip core concepts of standing waves in a visually stimulating way by making the flames dance to the rhythm of sound. In that way, even in this age of digital oscillators, Ruben’s Tube is difficult to beat.
