When it comes to the warmth and brightness of a summer day, it is all due to the sun. That being said, there are really 2 ways that we use this word: literally and figuratively. After all, when people speak of “fun in the sun,” they are likely not talking about the nuclear fusion core of the mostly-hydrogen G-type main-sequence star at the middle of our solar system, and a solar flare isn’t about that hairy guy down the street wearing a pink Speedo on a hot, sunny day. To the Egyptians, it was the god Ra, to the Greeks, helios, and to the Romans, solis, so what about our word?
Our word sun comes directly from the Old English sunne, which, as with other Germanic languages, such as Old Saxon and Old Norse (sunna) and the Old Frisian (sunne), comes from the proto-Germanic sunnōn.
In English, the first known uses can be broken down according to the meaning.
When considering it solely as a celestial body, the first known use comes from a translation by Ælfred in the middle of the reign of Alfred the Great (circa 888) of Boethius’ work, De consolatione philosophiæ (The Consolation of Philosophy), where he writes: “Hidden is the sun; all heaven Is obscured in starless night.” Interestingly, though we now make the distinction of capitalising the word when referring to our Sun (as opposed to the suns of other solar systems), outside of the realm of considering the Sun as a deity, this capitalisation distinction didn’t become more commonplace until circa 1500s.
As for our more figurative and vernacular usage, it is not as far removed from the celestial usage as we may think: this usage was first recorded in the Mercian dialect in An Old English Martyrology, circa 900, where it was written that St. Eastorwine “sat outside in the sun” before forsaking his earthly body and seeking the realms of Heaven.
Though we all enjoy a nice sunny day, it is important to take necessary precautions, such as limiting exposure. In the United States, about 90 percent of nonmelanoma skin cancers are associated with sun exposure, and, demonstrating how common this is, there are more new cases of skin cancer annually than the combined incidence of more publicised cancers, like breast, prostate, lung, and colon. Outside of cancer, there is always a risk of sun stroke, dehydration, etc. So, the next time you are having fun in the sun, be sure to be prepared!