Question

What most likely led to the change from the static universe theory to the expanding universe theory

Answer 1

Until 1931, physicist Albert Einstein believed that the universe was static.. An urban legend attributes this change of perspective to when American astronomer Edwin Hubble showed Einstein his observations of redshift in the light emitted by far away nebulae—today known as galaxies. But the reality is more complex. The change in Einstein's viewpoint, in fact, resulted from a tortuous thought process. Now, in an article published in European Physical Journal H, Harry Nussbaumer from the Institute of Astronomy at ETH Zurich, Switzerland, explains how Einstein changed his mind following many encounters with some of the most influential astrophysicists of his generation.

In 1917 Einstein applied his theory of general relativity in the universe, and suggested a model of a homogenous, static, spatially curved universe. However, this interpretation has one major problem: If gravitation was the only active force, his universe would collapse – an issue Einstein addressed by introducing the cosmological constant.

Answer 2

Answer:

Observation of red-shift in light coming from Galaxies

Explanation:

Till early 20th century it was believed that Universe is static. This viewpoint changed after Edwin Hubble observed Red-shift in the light coming from the far away galaxies. When an object moves away from an observer, the spectrum of light coming from this object will shift towards Red part. This is known as red-shift.

When various far off galaxies were studied red-shifting was observed in their spectrum, thus strengthening the expanding universe theory. Further studies including recent observation by Hubble Space telescope has strengthened this expanding universe theory and Big Bang theory.