Facts about Sunlight

£0.00

This diagram introduces sunlight, the light produced by the Sun, the star at the centre of our solar system.


It gathers together some useful facts and introduces some important terms that you can check out in the next section.

Remember that:

  • As the Sun explodes with the force of a billion one-megaton nuclear bombs every second it gives off electromagnetic radiation.
  • Sunlight is a form of electromagnetic radiation.
  • The electromagnetic radiation given off by the sun includes all wavelengths of the electromagnetic spectrum.
  • By the time sunlight has passed through the atmosphere and reaches the ground it contains infrared, visible, and ultraviolet wavelengths of light.
  • Viewed from the ground, sunlight contains a portion of the electromagnetic spectrum.
  • Viewed from outer space, sunlight contains all of the electromagnetic spectrum.
  • Without sunlight, life as we know it would not be possible because it carries the energy that plants need to grow and the heat that keeps the world warm.

Description

Facts about Sunlight

Facts about Sunlight

TRY SOME QUICK QUESTIONS AND ANSWERS TO GET STARTED
Sunlight can be described in terms of both waves and particles.
Sunshine is important to human beings because without light we can't see.
Other names for sunlight include daylight, sunshine, visible light, light and electromagnetic radiation!

About the diagram

About the diagram
  • This diagram introduces sunlight, the light produced by the Sun, the star at the centre of our solar system.
  • It gathers together some useful facts and introduces some important terms concerning the Sun and the electromagnetic radiation it emits.
Remember that:
  • As the Sun explodes with the force of a billion one-megaton nuclear bombs every second it gives off electromagnetic radiation.
  • Sunlight is a form of electromagnetic radiation.
  • The electromagnetic radiation given off by the sun includes all wavelengths of the electromagnetic spectrum.
  • By the time sunlight has passed through the atmosphere and reaches the ground it contains infrared, visible, and ultraviolet wavelengths of light.
  • Viewed from the ground, sunlight contains only a small portion of the electromagnetic spectrum.
  • Viewed from outer space, sunlight contains the whole of the electromagnetic spectrum.
  • Without sunlight, life as we know it would not be possible because it carries the energy that plants need to grow and the heat that keeps the world warm.

Some key terms

Energy is a property of matter and fields, which can be transferred between systems or transformed into different forms but cannot be created or destroyed.

  • Everything contains energy including all forms of matter and so all objects.
  • Energy is evident in all forms of movement, interactions between, and changes to the forms and properties of matter.
  • At an atomic level, energy is evident in the movement of electrons around the nucleus of an atom. Energy is stored in the nucleus of atoms as a result of the forces that bind protons and neutrons together.
  • Energy can be transferred between objects, and converted from one form to another, but cannot be created or destroyed.
  • Everything in the universe uses energy in one form or another.
  • When it comes down to it, matter is energy.
  • Light has energy but no mass so does not occupy space and has no volume.
  • Energy is often described as either being potential energy or kinetic energy.
  • Energy is measured in joules.

 

The electromagnetic spectrum includes electromagnetic waves with all possible wavelengths of electromagnetic radiation, ranging from low-energy radio waves through visible light to high-energy gamma rays.

  • There are no precisely defined boundaries between the bands of electromagnetic radiation in the electromagnetic spectrum.
  • The electromagnetic spectrum includes, in order of increasing frequency and decreasing wavelength: radio waves, microwaves, infrared radiation, visible light, ultraviolet radiation, X-rays and gamma rays.
  • Visible light is only a very small part of the electromagnetic spectrum.

Solar radiation is the electromagnetic radiation emitted by the sun.

  • Electromagnetic radiation is a type of energy that is commonly known as light. Detached from its source, it is transported by electromagnetic waves (or by their quanta, particles called photons) and propagates through space.
  • Electromagnetic radiation includes radio waves, microwaves, infrared, (visible) light, ultraviolet, X-rays, and gamma rays.
  • Electromagnetic radiation is sometimes called EM radiation or electromagnetic radiant energy (EMR).
  • All forms of electromagnetic radiation can be described in terms of both waves or particles.
  • All forms of electromagnetic radiation travel at 299,792 kilometres per second in a vacuum.

Electromagnetic radiation is a type of energy more commonly simply called light. Detached from its source, it is transported by electromagnetic waves (or their quanta, photons) and propagates through space at the speed of light.

  • Electromagnetic radiation (EM radiation or EMR) includes radio waves, microwaves, infrared, (visible) light, ultraviolet, X-rays, and gamma rays.
  • Man-made technologies that produce electromagnetic radiation include radio and TV transmitters, radar, MRI scanners, microwave ovens, computer screens, mobile phones, all types of lights and lamps, electric blankets, electric bar heaters, lasers and x-ray machines.
  • At the quantum scale of electromagnetism, electromagnetic radiation is described in terms of photons rather than waves. Photons are elementary particles responsible for all electromagnetic phenomena.
  • The term quantum refers to the smallest quantity into which something can be divided. A quantum of a thing is indivisible into smaller units so they have no sub-structure.  A photon is a quantum of electromagnetic radiation.
  • A single photon with a wavelength corresponding with gamma rays might carry 100,000 times the energy of a single photon of visible light.

Diagrams are free to download