Final answer:
Light energy is a type of electromagnetic radiation, perceived as visible light by humans, and is composed of photons that travel in waves. Its wavelength determines the energy level, with shorter wavelengths being more energetic. This energy is vital for life on Earth and has many applications, including photosynthesis.
Step-by-step explanation:
Light energy is a form of electromagnetic radiation emitted by the sun, which encompasses a range including gamma rays to radio waves. The portion that humans can perceive with our eyes is known as visible light. Visible light consists of photons, which are mass-less packets of energy that travel in waves. The wavelength of light, which is the distance between two consecutive crests or troughs of a wave, helps determine the energy of light; shorter wavelengths indicate more energy.
The concept of light as both a wave and a stream of particles exhibits the wave-particle duality at the quantum level. In practical terms, light energy has numerous applications, from enabling vision to being converted into electrical energy via photovoltaic cells. It is also essential for life on Earth, as seen in the process of photosynthesis where light energy is transformed into chemical energy used by plants.