These milestones including sitting up, rolling over, and crawling. Fortunately, by the time they were toddlers, these delays all seem to disappear no matter how your baby sleeps, so it's likely more appropriate to describe these kids as having a 'lag' in their development and not a true delay.
View full size image. In the early 1500s, when virtually everyone believed Earth was the center of the universe, Polish scientist Nicolaus Copernicus proposed that the planets instead revolved around the sun.iew full size image. In the early 1500s, when virtually everyone believed Earth was the center of the universe, Polish scientist Nicolaus Copernicus proposed that the planets instead revolved around the sun.
No Nicolaus Copernicus created it (although the planet's orbits were perfect circles in his model). Isaac Newton expanded on it. After Copernicus, Johannes Kepler stated that â¦the orbits were elliptical. Isaac Newton came up with the theory of universal gravitation.