Einstein's theories claim that the speed of light is a constant, i.e. it
cannot be changed. However, in the last few years scientists have been able to
slow light down to almost zero, and now they have managed to get to almost
infinitely fast. If human scientists can get light to change its speed then it
is no trouble for God, who created light, to vary its speed. Records of the
speed of light made over the last four centuries indicate that its speed was
faster in the past. The speed of light is a factor in many measurements used to
estimate the age and size of the universe, but scientists making these
estimations have assumed that the speed of light never changes. The experiments
described above challenge this belief. If faster speeds for light were put into
the age calculating equations they would give much younger dates.