G4V's Gravitational Radiation Theory

The labels are very difficult for me to tell exactly what they are. But it does seem like you've got a simple geometry for detector, and you've got in G4V's case a pretty simple theory. There was a question after the lecture where somebody raised a question about spin-two waves. I didn't really understand his answer about that because conventionally physicists say that general relativity and gravitational waves, they predict a spin-two radiation. Whereas electromagnetism is what? A spin-one? The photon is a spin-one particle,. They say that the graviton would have to be a spin- two particle.