what is the difference between light and darkness

The primary difference between light and darkness, from a scientific perspective, is that light is a physical entity, while darkness is the absence of the entity

Light (The Presence)
Light, specifically visible light, is a form of electromagnetic (EM) radiation that can be perceived by the human eye. 
• Physical Nature: Light is composed of photons, which are elementary, massless particles, and it travels as a wave (wave-particle duality). It is a form of energy. 
• Properties: It has measurable properties such as intensity, wavelength (which determines color), frequency, and speed (the speed of light, c, is a fundamental constant). 
• Sources: Light is emitted from a source, like the Sun, a fire, or an electric lamp. 

Darkness (The Absence)
Darkness is the condition that results from the absence or a significant lack of visible light. 
• Physical Nature: Darkness is not a physical substance or force; it is simply the state when light (EM radiation) is not present or is blocked. Similar to how “cold” is the absence of “heat” (thermal energy), “darkness” is the absence of “light” (radiant energy). 

• Perception: It is a perceptual concept based on the human eye’s inability to detect light.
• Creation: Darkness occurs when a light source is absent (like at night on the side of Earth facing away from the Sun) or when an opaque object blocks the path of light, creating a shadow. 

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