| R = 8.5×1028 cm = 2.7×1010 parsecs, | (17) |
| V = 1.1×1088 cm = 3.5×1032 cubic parsecs, | (18) |
| M = 1.8×1057 grams = 9×1022 ☉. | (19) |
The mass corresponds to 3.5×1015 normal nebulae.
The distance to which the 100-inch reflector should detect the normal nebula was found to be of the order of 4.4×1075 parsecs, or about 1⁄600 the radius of curvature. Unusually bright nebulae, such as M 31, could be photographed at several times this distance, and with reasonable increases in the speed of plates and size of telescopes it may become possible to observe an appreciable fraction of the Einstein universe.
Mount Wilson Observatory
September 1926
[1] Contributions from the Mount Wilson Observatory, No. 324.
[2] These are the two Magellanic Clouds, M 31, and M 33.
[3] Bailey, Harvard Annals, 60, 1908.
[4] Hardcastle, Monthly Notices, 74, 699, 1914.