No, electromagnetic (EM) waves do not lose amplitude as they travel through a vacuum or free space. Unlike sound waves, which require a medium to propagate and can experience attenuation due to air resistance, EM waves do not require a medium and can travel through empty space at the speed of light.
The amplitude of an EM wave represents the strength or intensity of the electric and magnetic fields oscillating perpendicular to each other and to the direction of wave propagation. As long as the EM wave is not interacting with any medium or experiencing absorption or scattering, it will maintain its amplitude over long distances.
However, it's important to note that in practical scenarios, EM waves can be subject to certain factors that may cause their amplitude to decrease. These factors include absorption by materials, scattering due to interaction with particles or objects, and diffraction effects. In such cases, the amplitude of the EM wave may decrease, but these effects are not inherent to the propagation of EM waves through vacuum or free space itself.
Additionally, the phenomenon of redshift, which is the stretching of wavelengths of light due to the expansion of the universe, can cause a change in the perceived frequency and energy of EM waves but does not affect their amplitude. The inverse square law, which describes the decrease in intensity with distance for a point source, applies to the spreading out of the energy over a larger surface area and does not involve a loss of amplitude for individual waves.