Types of Light Energy

Light energy is the only visible form of energy. Lots of things about light energy are discussed here. To know more about light energy, click here

Light Energy

Light energy is the only visible form of energy

Light is a form of energy which our sense of sight can detect. It is made of electro-magnetic radiation and travels in a straight path. In everyday we use the word “light” for at least 10 times a day!! Have you ever think about the energy we get from the light. Light is all around us. It has the ability to tan or burn our skins, it can be harnessed to melt metals, or heat our food. Light energy posed a huge challenge for scientist up to the 1950′s.

For our purposes we will use light to mean all of the frequencies of radiation, known as the electromagnetic spectrum or EMS. Light is always in motion and cannot be stored, so it is a kinetic type of energy.

You might say that light is essentially “pure” energy, since it theoretically has no mass. Light is simultaneously a wave and a particle. The higher the frequency, the more energy the light or electromagnetic radiation contains. The greater the frequency, the more energy each particle, called the photon.

Light energy Definition

  • Light energy refers to the electromagnetic energy that is visible to the human eye.

  • Light energy is energy that travels in straight lines called rays that fan outward from the source of the light?

  • Light energy is made of electro-magnetic radiation and travels in a straight path.

Types of Light Energy

Light energy can be classified as several types. They are:

Visible light: Only visible light can be seen through the naked eye. It is a type of electromagnetic energy. The main source of visible light is sun and it can also be emitted by lanterns, flashlight, light bulbs etc.

Infrared Light: It is also a type of electromagnetic energy which emits heat. It is used to switch on your Television with remote since infrared waves travel from your remote to the TV.

X-rays and Ultraviolet light: These are short light waves used by doctors to take photographs inside our body to find out fractures on our bone. Even dentists use x-rays to check the depth of tooth decay.

Key properties of light

Intensity: Intensity of light is the rate at which the light energy is emitted by the source. The power is often expressed in units of watts. Intensity can also be defined as brightness measured at the rate at which light is emitted in a unit of surface or energy per unit time per unit area.

Frequency: Frequency of light is defined as the number of crests which passes through a particular point in a second.

Wavelength: Wavelength of light is defined as the distance between the two consecutive crests or troughs. Light waves pass through a vacuum at the same speed. Wavelength and frequency of lightly related vice versa because the higher the frequency, the shorter is the wavelength.

Polarization: Polarization is a process in which unpolarized light is converted polarized light. In general, light waves vibrate in more than one plane and hence called as unpolarized light.

Phase: It is a particular point in the time period during the cyclic waveform. The intensity of light increases when the waves are in a phase.

Units of Light energy

Light can be measured in several units.

  • The wavelength of light λ is measured in both Angstrom and nanometers.
  • The frequency of light is measured in Hertz.
  • Light energy is measured in electron-volts (eV).