Short answers, pulled from the story.
Sound cannot exist in the void of space because it requires a physical medium to propagate. This fundamental limitation arises because sound is a mechanical wave that needs particles to collide and transfer energy, rendering the vacuum of space perfectly silent to human ears.
The French mathematician Pierre-Simon Laplace corrected Isaac Newton's formula by introducing the adiabatic factor, gamma, into the equation. This correction created what is now known as the Newton-Laplace equation and established that the speed of sound is proportional to the square root of the ratio of the bulk modulus of the medium to its density.
The human ear is sensitive to frequencies ranging from 20 Hz to 20 kHz, a range that defines the boundaries of what we can hear and shapes our perception of the world. Below 20 Hz, sound waves are heard as discrete stuttering sounds or rumbles, while above 20 kHz, sound waves are classified as ultrasound.
The speed of sound varies dramatically depending on the material it travels through, moving at approximately 343 meters per second in air at sea level. It accelerates to about 1,480 meters per second in fresh water and reaches speeds of roughly 5,960 meters per second in steel, with the fastest speed occurring in solid atomic hydrogen at approximately 12,000 meters per second.
Sound waves are transmitted through fluids as longitudinal waves, also called compression waves, which consist of alternating pressure deviations from the equilibrium pressure. Through solids, however, sound can be transmitted as both longitudinal waves and transverse waves, with transverse waves being waves of alternating shear stress perpendicular to the direction of propagation.
Acoustics is the interdisciplinary scientific study of mechanical waves, vibrations, sound, ultrasound, and infrasound in gaseous, liquid, or solid media. A scientist who works in the field of acoustics is called an acoustician, while an individual specializing in acoustical engineering may be referred to as an acoustical engineer.