GC: n
CT: Electricity can be static, like the energy that can make your hair stand on end. Magnetism can also be static, as it is in a refrigerator magnet. A changing magnetic field will induce a changing electric field and vice-versa (the two are linked). These changing fields form electromagnetic waves. Electromagnetic waves differ from mechanical waves in that they do not require a medium to propagate. This means that electromagnetic waves can travel not only through air and solid materials, but also through the vacuum of space.
S: MSNASA – http://missionscience.nasa.gov/ems/02_anatomy.html (last access: 9 December 2016)
N: 1. electromagnetic (adj): Also electro-magnetic, 1821; see electro- (before vowels electr-, word-forming element meaning “electrical, electricity”; latinized form of Greek elektro-, comb. form of elektron “amber”) + magnetic (1610s, literal; 1630s, figurative, from Modern Latin magneticus, from Latin magnes).
wave (n): “moving billow of water,” 1520s, alteration (by influence of wave (v.)) of Middle English waw, which is from Old English wagian “to move to and fro”. The usual Old English word for “moving billow of water” was yð.
2. Wave characterized by the propagation of a time-varying electromagnetic field.
3. Mechanical waves and electromagnetic waves are two important ways that energy is transported in the world around us.
4. Electromagnetic waves are formed by the vibrations of electric and magnetic fields. These fields are perpendicular to one another in the direction the wave is traveling. Once formed, this energy travels at the speed of light until further interaction with matter.
5. Electromagnetic waves have crests and troughs similar to those of ocean waves. The distance between crests is the wavelength. The shortest wavelengths are just fractions of the size of an atom, while the longest wavelengths scientists currently study can be larger than the diameter of our planet.
6. An electromagnetic wave can also be described in terms of its energy—in units of measure called electron volts (eV).
S: 1. OED – http://www.etymonline.com/index.php?allowed_in_frame=0&search=electromagnetic+wave (last access: 9 December 2016). 2. TERMIUM PLUS – http://www.btb.termiumplus.gc.ca/tpv2alpha/alpha-eng.html?lang=eng&i=1&srchtxt=electromagnetic+wave&index=alt&codom2nd_wet=1#resultrecs (last access: 9 December 2016). 3 to 6. MSNASA – http://missionscience.nasa.gov/ems/02_anatomy.html (last access: 9 December 2016).
OV: electro-magnetic wave
S: GDT – http://www.granddictionnaire.com/ficheOqlf.aspx?Id_Fiche=8401293 (last access: 10 December 2016)
SYN: EMW, EM wave.
S: GDT – http://www.granddictionnaire.com/ficheOqlf.aspx?Id_Fiche=8401293 (last access: 10 December 2016)
CR: bioelectricity, electric power station, electrical energy, Faraday’s law of electromagnetic induction, linear accelerator, magnetic energy, synchrotron, X-rays.
