How are they different from photons? Or gluons? Anyways, I saw a Freeman Dyson talk once where he explained that if you were to set up a detector with the cro

How are they different from photons? Or gluons? Anyways, I saw a Freeman Dyson talk once where he explained that if you were to set up a detector with the cross-sectional area of the Earth, and point it at the sun for the age of the Earth, you would be expected to detect 4(!) gravitons, due to their weak interactions with matter. He was convinced we would run into our inability to continue to test predictions long before we hammered out a decent unification theory.