Physics evolves through the knowledge that no theory, however tenable, must be held immutable. Hence this recent research:
"In recent years, several alternatives to general relativity have been proposed. These modified theories of gravity depart from general relativity on large scales to circumvent the need for dark energy, dark matter, or both. But because these theories were designed to match the predictions of general relativity about the expansion history of the universe, a factor that is central to current cosmological work, it has become crucial to know which theory is correct, or at least represents reality as best as can be approximated."
"The scientists' analysis of more than 70,000 galaxies demonstrates that the universe – at least up to a distance of 3.5 billion light years from Earth – plays by the rules set out by Einstein in his famous theory. While GR has been accepted by the scientific community for over nine decades, until now no one had tested the theory so thoroughly and robustly at distances and scales that go way beyond the solar system."
From "This is Getting Boring: General Relativity Passes Yet another Big Test! [March 18th, 2010]"
http://www.universetoday.com/2010/03/18/...other-big-test/
