Who showed that other galaxies existed nd observed that the universe is expanding?

Answer 1

Edwin Hubble showed that galaxies exist and he correlated galaxies to redshifts.

However, Hubble did not conclude that the redshift indicates the universe is expanding. Unfortunately, lesser Physicists have rushed to the conclusion that the Universe is expanding. Much of tthis is because Einstein's Relativity Equations only had solutions for expansion or contraction. of the two, Lemaitre called for expansion in his Big Bang, and this is the situation today.

Here is Hubble's position from an article:

http://apod.NASA.gov/diamond_jubilee/1996/sandage_hubble.html

Hubble concluded that his observed log N(m) distribution showed a large departure from Euclidean geometry, provided that the effect of redshifts on the apparent magnitudes was calculated as if the redshifts were due to a real expansion. A different correction is required if no motion exists, the redshifts then being due to an unknown cause. Hubble believed that his count data gave a more reasonable result concerning spatial curvature if the redshift correction was made assuming no recession. To the very end of his writings he maintained this position, favouring (or at the very least keeping open) the model where no true expansionexists, and therefore that the redshift "represents a hitherto unrecognized principle of nature". This viewpoint is emphasized (a) in The Realm of the Nebulae, (b) in his reply (Hubble 1937a) to the criticisms of the 1936 papers by Eddington and by McVittie, and (c) in his 1937 Rhodes Lectures published as The Observational Approach to Cosmology (Hubble 1937b). It also persists in his last published scientific paper which is an account of his Darwin Lecture (Hubble 1953).

The redshift is still an unrecognized principle of nature, The redshift is an indicator of Continuity, the balance between the centrifugal forces and the centripetal forces. Gravity potential energy gives the centripetal force and the vector energy gives the centrifugal force. Now some physicists deny the existence of centrifugal force. The fact is there is a centrifugal fforce and it is produced by the so-called "Dark Energy", which those same physicists affirm.

Hubble is correct, the Universe is not expanding and the redshift is no longer an unrecognized principle in nature, it is the "Fine Structure 'Constant' of matter, v/c is the redshift = square-root(GM/rc2).