Singing Rods – Absolutely incredible!
These Singing Rods are a classic science demonstration that are sure to grab your friends’ attention… and the people down the hallway… and every dog in the neighborhood! When your fingers are slid repeatedly along this long metal rod, an ear-piercing sound is generated. You control how loud the sound gets from a whisper to an auditorium-filling shriek. Absolutely incredible!
How Singing Rods work
Stroking the carefully balanced and calibrated aluminum metal rod with sticky fingers creates longitudinal vibrations in the rod. Longitudinal vibrations are waves that travel along the length of the rod. The waves travel to the end of the rod where they transmit vibrations to the surrounding air molecules. Longitudinal vibrations of air molecules are then interpreted by your ears as sound.
However, that is only part of the story. Some of the vibrations traveling toward the end of the aluminum rod are reflected. The reflected waves return and head back in the opposite direction toward your fingers. On their way back, they collide in a head on collision with similar waves created by your sticky fingers. The colliding waves either cancel each other out (nodes) or add up to create even bigger waves (antinodes).
Different sized rods produce different vibrations, so they produce different sounds. Long rods have a lower natural frequency while shorter rods have a higher natural frequency. If you rub the rod slowly, you will produce a relatively low sound. If you rub the rod aggressively, it will create an unpleasant high pitched sound (harmonics).
• Sold In A set Of 2 balanced and calibrated aluminum metal singing rods
• Includes A Bag Of Crushed Rosin To Lightly Coat Your Fingertips
• Approx. 20″ (500 mm) And 30″ (750 mm) L