- Richard of Wallingford (c1292-1336)
- Born in England.
- He designed an instrument, the rectangulus, which used seven straight pivoted rods, to solve problems in geometry of the sphere.
- He developed the albion, which used discs to calculate planetary equations.
- Born in Ireland.
- He built a 36-inch reflector for his telescope, and, later, a 72-inch one.
- He found spiral systems that are not of the Milky Way.
- With his assistants, he made numerous other discoveries.
- Born in USA.
- He developed a theory of evolutionary sequence of a star.
- He drew a diagram (H-R) similar to that of hertzsburg, but independently.
- Born in England.
- He studied radio waves from the Sun and more distant stars with an interferometer.
- He proved the theory of no big bang to to wrong.
Earl of Rosse (1800-1868)
Henry Norris Russell (1877-1957)
Martin Ryle (1918-1984)