Color The science of color is sometimes called chromatics, colorimetry, or simply color science. It includes the study of the perception of color by the human eye and brain, the origin of color in materials, color theory in art, and the physics of electromagnetic radiation in the visible range (that is, what is commonly referred to simply as "light"). Electromagnetic radiation is characterized by its wavelength (or frequency) and its intensity. When the wavelength is within the visible spectrum (the range of wavelengths humans can perceive, approximately from 390 nm to 700 nm), it is known as "visible light". Most light
Thorn in the flesh his other epistles do not directly address the topic. Throughout church history, there has been a significant amount of speculation about what Paul was referring to, although scholars such as Philip Edgcumbe Hughes, F. F. Bruce and Ralph P. Martin conclude that definite identification of the thorn is impossible with the evidence available. The "thorn" is most commonly interpreted as a reference to some form of serious physical infirmity that hindered his work. This is also the earliest known Christian interpretation, mentioned in the early third century in Tertullian's "On Modesty", where it is understood as a reference to ear