show more 26wks1dy pregnant. Why is it that in a singleton pregnancy, full term is considered 37wks, however in a twin pregnancy, full term is considered 35wks, & in a triplet pregnancy, full term is considered 31wks? Don't the babies in all pregnancies grow/develop at the same rate?hy is it that in a singleton pregnancy, full term is considered 37wks, however in a twin pregnancy, full term is considered 35wks, & in a triplet pregnancy, full term is considered 31wks?
For orbits around the Earth, see Geocentric orbit. In astronomy, the geocentric model (also known as geocentrism, or the Ptolemaic system) is a superseded description of the universe with the Earth at the center. Under the geocentric model, the Sun, Moon, stars, and planets all circled Earth.
A hypothetical geocentric model of the solar system (upper panel) in comparison to the heliocentric model (lower panel). While the sphericity of the Earth was widely recognized in Greco-Roman astronomy from at least the 3rd century BC, the Earth's daily rotation and yearly orbit around the Sun was never universally accepted until the Copernican Revolution.