The Expanding Universe

The Milky Way: Thomas Wright, from An Original Theory or New Hypothesis of the Universe

In 1750 Thomas Wright of Durham published An Original Theory or New Hypothesis of the Universe, in which he claimed to solve an old puzzle, the nature of the Milky Way. Assuming that "the Milky Way is formed of an infinite Number of small Stars," he imagined "a vast infinite Gulph, or Medium, every Way extended like a Plane, and inclosed between two Surfaces" (see his Plate XXIII, shown at right). An observer placed near the center (point A in the plate) would see bright stars nearby, then fainter and fainter stars retreating into the distance:

Only imagine how infinitely greater the Number of Stars would be in those remote Parts, arising thus from their continual crowding behind one another, as all other Objects do towards the Horizon Point of their Perspective, which ends but with Infinity: Thus, all their Rays at last so near uniting, must meeting in the Eye appear, as almost, in Contact, and form a perfect Zone of Light; this I take to be the real Case, and the true Nature of our Milky Way.

Wright's hypothesis that our galaxy is shaped like a disk, along a flat plane, proved influential on Immanuel Kant and William Herschel (see Herschel's 1784 illustration of the Milky Way).

For theological reasons, Wright went on to posit an infinite number of other universes, created by "an infinite all-active Power" who has filled "the endless Immensity" with "an unlimited Plenum of Creations." In Plate XXXII, each of the disks represents a universe like our own, centered around "the most perfect of Beings."