Why is the speed of light said to be constant?

The speed of light is constant because it does not change with respect to the observer's view, and its speed of light does not change irrespective of location or time. As a matter of fact, this is a guess that was made by Albert Einstein some years ago.

Scientists are already proving this to be wrong. It's now being postulated that the speed of light can only be constant in a vacuum. The density of a medium can also affect the speed of light. It was said that the speed of light is discovered to be slower in liquid, and even water. It was also discovered that the speed of light decreases when it passes through a diamond.

But it has already been included in the textbooks for all schools and colleges over the world that the speed of light is constant. This postulate has been accepted by many people, and an average person would tell you that the speed of light is constant, even science students.

When it comes to determining whether the speed of light is constant or not, there are a few things to be taken into account. Any change can make the speed of light faster or slower, depending on the variables that are present. If the molecular bonds are changed, the pace could change itself.

Every book will tell you that the speed of light is constant, however, there are new theories that are coming to light which are challenging this statement. Nothing stays constant forever in the universe. There are new stars, new moons, and other phenomena discovered each year. While planets undergo change, it would stand to reason that the universe itself goes through changes as well.

The study of astronomy and cosmology are assisting in determining whether the speed of light truly does remain constant, or whether there are variables that can either make it a bit faster or slower, depending on the environment.