Chinese sun and moon mirrors being hung round the neck, or because necks are concave things. Liu An's (c. 139 BCE) "Huainanzi" "Masters of Huainan", which is a compendium of writings from various schools of Chinese philosophy, was the first text to record "fangzhu" dew-collectors. Two "Huainanzi" chapters metaphorically use "sun and moon mirrors" to exemplify "yang" and "yin" categories and elucidate the Chinese notion of "ganying" "cosmic resonance" through which categorically identical things mutually resonate and influence each other. The "yángsuì" 陽燧 "burning-mirror" is "yang", round, and sun-like; the "fāngzhū" 方諸 "square receptacle" is "yin", square, and moon-like. The first context describes "yangsui" and
Yin and yang 阳 "sunny side" are linguistically analyzable in terms of Chinese characters, pronunciations and etymology, meanings, topography, and loanwords. The Traditional Chinese characters and for the words "yīn" and "yáng" are both classified as radical- esphonetic characters, combining the semantically significant "mound; hill" radical or with the phonetic indicators "ying" and "yang" . The first phonetic "yīn" "cloudy" ideographically combines "jīn" "now; present" and "yún" "cloud", denoting the "今 presence of 云 clouds". The second phonetic "yáng" "bright" originally pictured the "sun" with "rays coming down". This phonetic is expanded with the "sun" radical into "yáng" 暘 "rising sun; sunshine". The