No, it is not correct to say that gravitational waves have no energy and are not absorbed. Gravitational waves do carry energy, and they can interact with matter and be absorbed under certain circumstances.
Gravitational waves are ripples in the fabric of spacetime caused by the acceleration of massive objects, such as black holes or neutron stars. According to Einstein's theory of general relativity, these waves propagate outward from their source at the speed of light.
Gravitational waves carry energy away from their source as they propagate through spacetime. This energy is derived from the motion and acceleration of massive objects. As gravitational waves pass through matter, they can transfer some of their energy to the material, causing it to vibrate or deform.
However, the absorption of gravitational waves by matter is generally very weak compared to other types of waves, such as electromagnetic waves. This is because gravitational waves interact with matter through the distortion of spacetime itself, which is a much weaker interaction compared to the electromagnetic force.
To detect gravitational waves, scientists use extremely sensitive instruments called interferometers. These devices are designed to measure the minuscule displacements caused by passing gravitational waves. The fact that gravitational waves can be detected and measured is evidence that they carry energy and can interact with matter, albeit with a relatively weak effect.
In summary, gravitational waves do possess energy, and while their interaction with matter is generally weak, they can be absorbed and cause measurable effects on the material they encounter.