  A spherically symmetric and static metric that describes physical coordinates
is introduced. It is defined to be a metric that gives coordinate independent
results for physically observable quantities without a further coordinate
transformation. The suggested metric also makes a prediction for the second
order gravitational red shift effect that can be utilized for a precision
experimental test in the future. A possible new experimental test would be
provided by a modern Michelson Morley experiment on the earth with the two arms
in vertical and horizontal directions to see the validity of isotropy or
anisotropy for the speed of light. The possibility of using pulsars and GPS
(Global Positioning System) for a general relativity test is discussed.
