Where dark matter once seemed as ad hoc as Milgrom's proposal, it had over the past decade morphed into a full - blown theory that explained far more than just the peculiar movement of stars in galaxies. (discovermagazine.com)
He presented the world with the theories that the rotation of the Earth is responsible for the daily movement of the stars, and that the cycles of the seasons are due to the Earth revolving around the sun. (babygaga.com)
In 1838, Bessel observed the apparent back - and - forth movement of the star 61 Cygni that results from our shifting perspective as Earth orbits the sun, an effect known as parallax. (discovermagazine.com)