Essay On Speed Of Light In A Vacuum

1 Introduction

1.1 Background

One of the most important physical constants in the world of Physics is the speed of light in a vacuum. This is the limiting speed for all material objects according to Einstein’s theory of relativity. The speed of light in a vacuum, or c, is what controls the laws of both the general and special relativity. Whenever light is in a vacuum, its speed has an exact value of c, no matter who measures it. Even if the vacuum is inside a box in a rocket traveling away from earth, both an astronaut in the rocket and a hypothetical observer on earth will measure the speed of light moving through that box to be exactly c. A faster speed cannot be measured. Indeed, c is the ultimate speed limit of the universe. However, we cannot say that nothing travels faster than light. Although the speed of light matters greatly, so many people do not know the fact that the speed of light is not a constant at all. The speed of light is very diverse as there exist various mediums in our world. As light travels through different materials, it scatters off of the molecules in the material and slows down. Nothing ever travels faster than c in vacuum, however, for different mediums, this is not the case. In materials such as water, light will slow down more than electrons will. Thus an electron in water can travel faster than light in water. The amount by which light slows in a given material is described by the index of refraction, or in other words, n. The index of refraction of a material is

My experiment mainly aims to answer this question:

‘How does the density of water affect the speed of light propagating through that very medium under constant temperature and pressure, while the structural and material qualities of the container used to contain the medium within are kept