. On this day in 1840 – July 1st – Irish astronomer, lecturer and astronomy popularizer, Robert Ball, was born in Dublin.
Ball was a university professor and the Royal Astronomer in Ireland. He was well known to the public for his books on astronomy, and for his public lectures. Between 1875 and 1910 he gave around 2500 lectures in towns and cities across Britain and Ireland.
. On this day in 1917 – July 1st – the 100" mirror for the Hooker telescope arrived at Mt Wilson Observatory.
This telescope was the biggest in the world for three decades. Edwin Hubble calculated the distance to Andromeda from a Cepheid variable he discovered there with the telescope. It showed Andromeda was a separate galaxy. Hubble and Milton Humason also observed the redshifts of a number of galaxies and found that they were moving away from us.
Philosophiæ Naturalis Principia Mathematica (Latin for 'Mathematical Principles of Natural Philosophy') states Newton's laws of motion and of universal gravitation. It's regarded as one of the most important works in the history of science.
We take forum safety very seriously here at BellaOnline. Please be sure to read through our Forum Guidelines. Let us know if you have any questions or comments!