Vacuum Acoustic Confinement Effect_ Theory and Experimental Design for Efficient Deposition of Acoustic Energy at SolidLiquid-Vacuum Interfaces

Abstract Traditional acoustic theories generally hold that a vacuum cannot transmit airborne sound waves, and the scientific community has long regarded vacuum solely as a passive sound-insulating medium, largely overlooking its critical role in confining acoustic energy within solid and enclosed liquid media. This represents a longstanding key academic gap in the field of acoustic energy regulation at solid/liquid-vacuum interfaces. As an independent original theoretical study with no affiliated institution or external funding support, this work draws on the core solid-borne sound transmission principle demonstrated in Bell’s early paper cup telephone model, departs from the conventional vacuum sound insulation research framework, and formally introduces the original physical mechanism of the Vacuum Acoustic Confinement Effect (VACE), redefining the interaction between vacuum and acoustic waves. The results demonstrate that a vacuum does not merely block acoustic wave propagation; instead, by eliminating the gaseous phase and forming a total reflection boundary at solid/liquid-vacuum interfaces, it fully confines acoustic energy within solid and enclosed liquid media, eliminating acoustic radiative dissipation and air damping losses, and significantly enhancing the local deposition efficiency of acoustic energy. Conducted without experimental or simulation data support, this study focuses on pure theoretical construction: it systematically derives the core theoretical equations of the effect, defines the confinement boundary conditions for acoustic waves across different media and frequency bands, designs a standardized controlled experimental scheme, and analyzes the transformative application potential of the effect in scenarios including extreme space environments, ultra-precision machining, and waste acoustic energy recovery. This work fills the academic gap in acoustic energy regulation for macroscopic solid/liquid media in vacuum environments, overcomes the energy loss bottleneck of conventional acoustic technologies, and provides novel theoretical support for emerging fields including advanced acoustic machining, space equipment manufacturing, and energy recycling. Update 1 | Rights Confirmation 2) both reimagine the "disadvantages" of acoustic waves as advantages through reverse thinking. In the first paper, I addressed attenuation by moving the sound source itself and broke through defenses using dual frequencies. In this work, I reverse the conventional understanding that "sound cannot propagate in a vacuum" to recognize that "sound waves in solids or sealed liquids cannot escape into a vacuum"—thus, they are confined within the solid or liquid medium. Now, here’s the most intriguing part: there are three well-established physical principles. First, sound cannot propagate in a vacuum. Second, due to this inability, no medium exists to conduct sound waves from solids or sealed liquids in a vacuum to the outside. Third, the law of conservation of energy. Therefore, the logic of my Vacuum Acoustic Confinement Effect (VACE) is inherently valid—no experiments are needed because it is built on axioms. So, how can one refute it? Deny that sound cannot propagate in a vacuum? Deny that sound waves can be conducted without a medium? Or deny the law of conservation of energy? You will find it impossible to refute, because doing so would mean overthrowing fundamental physics—leading others (and even yourself) to question your basic scientific literacy. Without a conducting medium, sound waves are inevitably confined within solids or sealed liquids in a vacuum. By the law of conservation of energy, the mechanical energy of the sound waves is converted into thermal energy, which repeatedly reflects at the solid/liquid-vacuum interface and remains within the medium, continuously transforming into mechanical forces and heat. Notably, in a vacuum, thermal energy can only dissipate through thermal radiation. Can you imagine the immense value and impact this paper, or the theoretical concept of VACE itself, will have on the academic community? It may spawn a series of new disciplines and drive significant changes in research, manufacturing, space exploration, education, and other fields. All this stems from a seemingly small breakthrough—the physical mechanism or phenomenon I term the Vacuum Acoustic Confinement Effect. Isn’t it fascinating? Everything begins with a shift in perception—a cognitive barrier that most people never overcome in their lifetimes.