Sound Energy vs Light Energy
Light and sound are the two main methods that give information about the nature around them. The propagations of light energy and sound energy are very important in the survival of the mankind. The study of light energy and sound energy is widely done in fields such as acoustics, LASER technology, electromagnetic theory and various other fields in physics and engineering. It is vital to have a proper understanding in these concepts in order to understand the related fields and excel in such fields. In this article, we are going to discuss what light energy and sound energy are, the definitions of these two concepts, their applications, similarities, and finally the difference between light energy and sound energy.
Sound is one of the main methods of sensing in the human body. We encounter sounds every day. A sound is caused by a vibration. Different frequencies of vibrations create different sounds. When the source vibrates the molecules of the medium around it also starts to oscillate, creating a time varying pressure field. This pressure field is propagated throughout the medium. When an audio receiving device such as the human ear is exposed to such a pressure field, the thin membrane inside the ear vibrates according to the source frequency. The brain then reproduces the sound using the vibration of the membrane. It can be seen obviously, that to propagate sound energy there must be a medium that is capable of creating a time varying pressure field. Thereby sound cannot travel inside a vacuum. Sound is a longitudinal wave because the pressure field causes the particles of the medium to oscillate in the direction of the energy propagation.
Light is an electromagnetic wave. The energy of an electromagnetic wave depends only on the frequency of the wave. Light is propagated using packets of energy called photons. This was explained in quantum mechanics. For a light at a given frequency, each photon carries the same amount of energy. One of the most important aspects of light is that it does not require a medium to propagate. Since the wave is inside the propagated particle itself, there is no need for an external medium to propagate. The speed of light in a vacuum is the fastest speed any object can obtain. When light incident on the nerve ends of the eye is detected by the nervous system, a signal is sent to the brain with the energy of the incident photon. The image is reproduced inside the brain.
What is the difference between Light Energy and Sound Energy?
• Light is a form of electromagnetic wave, whereas sound is a pressure density wave.
• Light does not require any medium to travel but sound does require a medium to travel.
• Light energy is quantized in packets of energy called photons, but sound energy is a continuous stream of energy on the scale.
• The energy of the light depends on the frequency of the incident light, but the energy of the sound depends on the amplitude of the incident sound.