Einstein had looked at the numbers and dimensions that went into his equations for gravitational waves and said, essentially, 'This is so tiny that it will never have any influence on anything, and nobody can measure it.' And when you think about the times and the technology in 1916, he was probably right.

All at once, funding was gone due to the Mansfield Amendment, which was a reaction to the Vietnam War. In the minds of the local RLE administrators, research in gravitation and cosmology was not in the military's interest, and support was given to solid-state physics, which was deemed more relevant.

The obvious thing to me was, let's take freely floating masses in space and measure the time it takes light to travel between them. The presence of a gravitational wave would change that time. Using the time difference, one could measure the amplitude of the wave.

Rainer Weiss Quotes