Fascinating Facts About Light: Speed, Colors, and Scientific Wonders

Sunlight appears white but Contains all Colors

The color of light from the sun may appear white but it is actually a combination of all visible colours. When this white light travels through prism, it is dispersed into its constituent colors.

The Speed of Light: Fastest in the Universe:

Light is the fastest thing in the universe, traveling at a speed of 300,000 kilometers per second. The only other known phenomenon that travels at the speed of light is gravity.

Gravitational Lensing: How Light Bends Around Massive Objects:

Light usually travels in a straight line; however, it can also bend due to the gravity of a massive object, which curves spacetime. This phenomenon is called gravitational lensing. A black hole appears black because its gravitational pull is so strong that even light cannot escape.

Source : NASA, ESA
The massive galaxy cluster MACS J1149.6+2223, located about 5 billion light-years away, acts like a cosmic magnifying glass. Its immense gravity bends and amplifies light from distant objects behind it—a phenomenon known as gravitational lensing. Thanks to this effect, astronomers were able to observe Supernova Refsdal, a stellar explosion that happened more than 9 billion light-years away. What makes SN Refsdal special? It’s the first supernova ever discovered through gravitational lensing, appearing multiple times in different locations due to the cluster's powerful gravitational influence.

How Long Does Light Take to Travel?

Despite being the fastest in the universe, light does take time to travel. For example, it takes about 8 minutes for light from the Sun to reach Earth. Therefore, what we see of the Sun is how it appeared 8 minutes ago. Similarly, light takes about 4 years to travel from the nearest star, Proxima Centauri, to Earth. Consequently, what we observe of Proxima Centauri is how it looked 4 years ago.

The Wave-Particle Duality of Light:

Initially, Light was believed to have particle-like properties. Later, scientific research suggested that light exhibits wave-like behavior. Today, based on extensive scientific research, it is widely accepted that light possesses both wave and particle-like properties, a phenomenon known as wave-particle duality.

Why Does Light Refract in Different Mediums?

Light travels slower in Glass and water than in vacuum and air. Light refracts when it passes from one medium to another due to a change in its speed.

Why Light Disperses in a Prism?

Different wavelengths of Light do travel at differ speeds in a dense medium such as a glass. This is due to the interaction of Light with atoms and molecules. As a result if light passes through a prism or any dense medium Light gets dispersed into its constituent colors.

Why Is the Sky Blue? The Science of Rayleigh Scattering

The sky appears blue because Earth's atmosphere scatters blue light more than red light, a phenomenon known as Rayleigh scattering. However, from space, the sky appears black, and the Sun looks extremely bright. Additionally, shadows in space are very sharp due to the absence of atmospheric scattering.

Source : NASA, ESA
Astronauts aboard the International Space Station (ISS) get a stunning, unobstructed view of it—one that’s very different from what we see on Earth. Sky appears completely black, even in broad daylight. Sun, instead of being softened by a blue sky, looks blindingly bright and sharp

Why Sunsets and Sunrises Appear Red?

The Sun and sky appear red during sunrise and sunset because sunlight passes through a greater thickness of the Earth's atmosphere, scattering shorter wavelengths (blue and violet) and allowing longer wavelengths (red and orange) to dominate.

Beyond Visible Light: The Electromagnetic Spectrum

The light visible to the human eye is actually only a small fraction of the entire electromagnetic spectrum. However, some animals can perceive a broader range, including infrared and ultraviolet wavelengths. Certain snakes, such as pythons, can detect infrared light, while birds like owls and pigeons can see ultraviolet light.

How We Perceive Colors: The Role of Light Reflection

The colors we see exist because objects reflect certain wavelengths of light while absorbing others. Our brain then interprets these signals, transforming them into the vibrant spectrum of colors we perceive.