We've never seen THIS before - James Webb Space Telescope

Alright, I truly enjoy both your bubbly enthusiasm for your subject matter, but ESPECIALLY how well you can take extremely complex physics concepts and bring them into a more understandable form. In that vein I would truly appreciate your explanation of how LIGOS works, and by that I mean how can a gravitational wave be measured with a light beam when a gravitational wave travelling through the space the light is travelling through is stretched, presumably to the same degree as the measurement that would reveal it. I've seen the Veritasium video on this however that wasn't what I'd call an explanation I can repeat as if I understand it completely. So... if you choose to accept the mission, well... that's the mission.