Definition of the word radiate

The word "radiate" finds its origin in the Latin verb "radiāre," meaning "to burst forth, to spread out" or "to emit rays." The Latin noun "radius" also shares the same roots, and it refers to a rod, or stick, which was used as the principal unit for measuring objects during ancient Roman times. The concept of radiating or emitting rays can be traced back to medieval times when scientists began to understand that some substances, such as minerals and metals, radiated an aura or glow. The phenomenon known as "luminous properties" was studied in the study of alchemy. The use of the term "radiate" in science can be found in the 18th century when Thomas Young, a British polymath, coined the term "radiant heat" to describe the heat that was emitted from a sterile source. In the 19th century, the term "radiation" began to be used in physics to describe the transmission of energy through empty space. Today, the word "radiate" is widely used in science to describe various phenomena such as the emission of radiation by the sun, the dispersion of energy by a radio antenna, and the spreading of matter from a point as in a star's core. In medicine, the term "radiating pain" refers to a dull, achy sensation that spreads from its source or origin.