The famous line from the movie Alien asserted, “In space, no one can hear you scream.” However, physicists Zhuoran Geng and Ilari Maasilta from the Nanoscience Center at the University of Jyväskylä, Finland, have recently presented groundbreaking research that challenges this notion. Their study suggests that, under specific circumstances, sound can indeed travel powerfully through a vacuum, defying conventional understanding.

Their remarkable findings, recently published in the journal Communications Physics, unveil an intriguing phenomenon: sound waves have the potential to “tunnel” through a vacuum gap between two solid objects, provided these objects are piezoelectric in nature. Piezoelectric materials exhibit an electrical response when subjected to sound waves or vibrations. Importantly, as an electric field can exist within a vacuum, it can effectively facilitate the propagation of these sound waves.

This unique phenomenon is contingent upon the size of the gap being smaller than the wavelength of the sound wave itself. Remarkably, this effect spans beyond the audio frequency range (Hz-kHz) and extends to ultrasound (MHz) and hypersound (GHz) frequencies. The crucial condition is that the vacuum gap must decrease in size as the frequency increases.

“While the effect may often be subtle, we have also identified instances where the entire energy of the wave seamlessly crosses the vacuum with 100% efficiency, void of any reflections. As a result, this phenomenon holds promise for applications in microelectromechanical components (MEMS) such as smartphone technology, and it could also revolutionize heat control,” explains Professor Ilari Maasilta from the Nanoscience Center at the University of Jyväskylä.

This groundbreaking discovery challenges the long-standing perception that space is a void devoid of sound transmission. As the potential applications continue to unfold, from enhancing modern technology to refining heat management, the research of Geng and Maasilta reshapes our understanding of acoustics and sound transmission, demonstrating that even in the vacuum of space, sound can still find a way to make its presence known.

By Impact Lab