It is a simpler way of measuring very long distances, which is what we have in the Universe.
Joseph Swan invented light bulb in 1879
Well, because we need to know the light year
1868
Thomas Edison invented the light bulb in 1879.
The light bulb was created in 1882 by Thomas Edison.
He invented the electric light in 1880
The flourescent light bulb was invented in 1827.
The year that New York got its first electric light system was in 1896.
The first traffic light was invented in 1903 by William L. Potts.
Thomas Alva Edison invented the light bulb in 1877.
Thomas Edison invented the light bulb 1876 an the camera 1890
The light bulb was invented by Thomas Alva Edison in 1879.