Does Light Get Fainter As It Travels?

Light is a work of nature that is visible to the human eye. The sun exposes us to light every day, along with several other human-made lights. The use of lights is essential to our lives, especially during our modern world, wherein some people tend to work at night. Furthermore, light itself has a lot of fascinating features, along with several mysterious phenomena.

It is a common conception that light is the fastest among anything else, and it could travel for extreme distances. In this article, we are going to look into some of the properties of light, and mainly, does light get fainter as it travels? Despite its speed and distance, we may say that the energy of light has a limit when it moves. But does this limit applies every time light travels? How does light moves for billions of lightyears to Earth?

What is light?

First and foremost, let us look further into the properties of light. Light is electromagnetic radiation that is visible to the human eye. Scientists theorized that light is the fastest, and nothing can move faster than it.

Light is an energy that moves in wavelengths. This energy is made up of photons, which are full of energy.Similar to sound, this light energy travels in waves, although it is significantly faster than the speed of sound. The light varies in strength, and that is why some lights are weaker compared to others, as it mainly depends on the amount of energy present in the light.

As mentioned earlier, the speed of light is the fastest, and it travels at a rate of 300,000 kilometers per second or 186,000 miles per second in a vacuum. This exceptional speed is what astronomers use to measure heavenly bodies, called a lightyear.

A lightyear represents the distance that light could travel around the Earth for one whole year. It means that one lightyear is equivalent to 9.46 trillion kilometers or 5.88 trillion miles. This incredible distance is far enough to measure the distances between stars, planets, and other heavenly bodies.

Does light get fainter?

Now that we already have brief information about light let us look further into its properties. Mainly, does light energy weakens when it travels? We all probably know or noticed that if we are farther away from the source of light, the less bright it seems.

For starters, light energy gets weaker as it travels. However, light travels in space, and its wavelengths would have pretty much fewer interruptions, which allow it to maintain its original energy most of the time. Another example is if a baseballtravels in space, it will continue to move forward for about thousands of years. It is because the ball does not have many interruptions like air resistance, friction, etc., when in space. The same thing goes in light. If light travels in vacuum or space, the less resistance will allow it to travel in greater distances – explaining why it could travel for billions of lightyears from stars to Earth.

However, if light travels in places with more resistance, like here on Earth, it will not have the same effects as to moving in space. Earth has an atmosphere, water, and gravity, which means light can only move limitedly. An example of this is when light travels within a glass of water, some of its energy will get absorbed, which will turn into heat energy. It also explains why when light hits the ocean; it can only cover most of the surface. Light cannot travel deep within the ocean, which is why some parts of itare pitch black.

Besides water, air resistance is also a factor in dissipating light wavelengths. When the light waves reach our atmosphere, the gases and particles on Earth will react to it.  These gases and particles that are present in our atmosphere will cause the light waves to scatter, and some of it would get absorbed. This process will gradually weaken the light energy incoming to the planet’s surface. Both of these processes of absorption and scattering will continue to take place in our atmosphere, creating a cycle of energy – losing light energy in place of heat.