# What makes us think we can actually detect gravitational waves?

This refers to the discussion about gravitational waves for the YouTube video LIGO Gravitational Wave Observatory.

I have two questions:

1. When the gravitational wave passes through the space where the light is traveling, the light beam will itself be distorted as per the distortion of space (because the gravitational wave distorts everything in its path) and the slight change they expect to detect should be nullified. For instance, suppose the wave shrinks one of the pipes by half and increases the other by double, the waves inside would be distorted similarly, resulting in no overall change in the interference. Am I missing something here?

2. It takes a huge amount of energy to distort something (for example, a block of iron). If the gravitational wave distorts everything it passes through (such as the Earth, the Sun and space itself), it will lose its energy at a very high rate in trying to do this distortion (much more than what the inverse square law implies) when it passes through solid objects. The current understanding is that gravitational waves do not get effected by anything and pass through a solid as if was vacuum. How is this possible?