Fundamental Constant May Depend on Where in the Universe You Are - ScienceNOW: Light from the quasars must pass through clouds of gas on its several-billion-year journey to Earth, and the atoms in the gas absorb light of specific wavelengths. So the spectrum of the light reaching Earth is missing these wavelengths and looks a bit like a bar code. The overall shift of the lines tells researchers how far away a gas cloud is and, hence, how long ago the light passed through it. The relative spacing of the lines lets them estimate the fine-structure constant at that time. Analyzing such data, Webb and colleagues argued that the fine-structure constant was about 1 part in 100,000 smaller 12 billion years ago than it is today...
Now Webb and his colleagues have scoured the southern sky themselves using the VLT. Their 153 clouds suggested a difference of 1 part in 100,000 in the fine-structure constant 12 billion years ago. Except in the southern sky, the constant seems to be larger. Connecting the two extremes with a line, the team found that absorption patterns in the clouds along that line are consistent with the fine-structure constant changing slowly through space—smaller in the distant northern sky and larger on the southern side.