Planets. The planets were thought by Ptolemy to orbit Earth in deferent and epicycle motions.
Although the idea that the planets orbited the Sun had been suggested many times, it was not until the 17th century that this view was supported by evidence from the first telescopic astronomical observations, performed by Galileo Galilei. By careful analysis of the observation data, Johannes Kepler found the planets' orbits were not circular but elliptical. Words. The term word may refer to a spoken word or to a written word, or sometimes to the abstract concept behind either.
Spoken words are made up of units of sound called phonemes, and written words of symbols called graphemes, such as the letters of the English alphabet. Definitions[edit] Semantic definition[edit] Leonard Bloomfield introduced the concept of "Minimal Free Forms" in 1926.
Moon.