The Expanding UniverseIn modern times, first German, then English became the principal language of astronomy. Attention shifted from the planets to the stars, then to the immense expanding universe of galaxies, created billions of years ago in a "Big Bang." Modern scientists, unlike Copernicus or Newton, first use papers in journals to introduce new ideas to their fellow researchers, and then books to spread those ideas to a wider scientific community or the general public. Classic scientific papers and books illustrating this giant step to an expanding universe conclude the display.
Bessel, Friedrich Wilhelm, 1784-1846
Abhandlungen von Friedrich Wilhelm Bessel. Hrsg. von Rudolf Englemann... in drei banden.
Leipzig, W. Englmann, 1875-76.
Friedrich Wilhelm Bessel, a leading German astronomer and mathematician, was the first person to measure the distance to a star other than a sun. He used the special type of telescope called a heliometer that is shown here in a collection of his astronomical papers.