Thank you for all your replies. I have read the articles you provided that explain the light as more of a clock, rather than ruler; and that red and blue shift effects following a gravitational wave cause the arrival times to differ. But I was more interested in the effect gravitational waves...
A question from a physics laymen to those more advanced: if eLIGO detects gravitational waves by the difference to the combined laser wavelengths (a difference to the destructive interference pattern following curvature of space-time in each individual pathway), how is it that the lasers...