Relativity in brief... or in detail..
6. Beyond relativity?
Einstein's theory of gravity is also called relativity: General Relativity. The two relativity theories are fundamental in cosmology, the study of the Universe as a whole. In 2004, NASA launched Gravity Probe B, whose purpose is to decide among types of theories of gravitation. So we may know more about that soon.
Special Relativity has survived the most stringent experimental tests and there is no serious competition for most of its applications. However, at extremely high energies and unimaginably small scales—on what we call the Planck scale —there are suggestions that Relativity might need some adjustments. We don't know yet. Nevertheless, just as we continue to use Newtonian mechanics when speeds are modest, we shall continue to use relativity, no matter what peculiar new results might be discovered.
Written and presented by Joe
Production and multimedia by George