Because of their dual nature as particles and waves, photons are often depicted as squiggly lines.
Click on image for full size
Windows to the Universe original artwork by Randy Russell.
Light is very strange. Sometimes it is best to think of light as a series
of waves. At other times, it is useful to think of light as a swarm of particles.
When we think of light as particles, we call those particles of light "photons".
Photons are the carriers of all forms of electromagnetic
(EM) radiation, not just light. The different types of EM radiation correspond
to different amounts of energy per photon. Gamma
ray and X-ray photons have
the most energy, radio
frequency photons have the least energy, while ultraviolet,
infrared, and visible
light photons have intermediate energies.
Photons travel at the speed of light, which is 299,792.458 kilometers per
186,282.4 miles per second)! Photons don't have any mass, nor do they carry an electrical charge.
Shop Windows to the Universe Science Store!
Our online store
includes issues of NESTA's quarterly journal, The Earth Scientist
, full of classroom activities on different topics in Earth and space science, ranging from seismology
, rocks and minerals
, and Earth system science
You might also be interested in:
Electromagnetic radiation is the result of oscillating electric and magnetic fields. The wave of energy generated by such vibrations moves through space at the speed of light. And well it should... for...more
Radio waves are a type of electromagnetic radiation. A radio wave has a much longer wavelength than does visible light. We use radio waves extensively for communications. Radio waves have wavelengths as...more
The thermosphere is a layer of Earth's atmosphere. The thermosphere is directly above the mesosphere and below the exosphere. It extends from about 90 km (56 miles) to between 500 and 1,000 km (311 to...more
Radiation comes in two basic types: electromagnetic radiation transmitted by photons, and particle radiation consisting of electrons, protons, alpha particles, and so forth. Electromagnetic radiation,...more
Sometimes when a photon hits a molecule, the energy from the photon causes the molecule to break apart. Scientists use the term "photodissociation" for such events. Photodissociation plays a very important...more
Ozone is a special kind of oxygen molecule. Normal oxygen molecules (O2), the kind we need to breathe, have two oxygen atoms. Ozone molecules (O3) have three oxygen atoms. Ozone forms when a photon of...more
The force of magnetism causes material to point along the direction the magnetic force points. This property implies that the force of magnetism has a direction. As shown in the diagram to the left, the...more