I would like to candle some goose eggs that I suspect are rotten. I have never candled before and know very little about it, only watched some videos, but there are no videos of candling rotten eggs, just early-stage unfertilized ones. The eggs are about 30 days old, so any idea of what it would look like needs to factor in that they have been incubated for quite some time. Would an unfertilized egg look different at 30 days vs 7 days if it was actively incubated, and would it look different if the problem was embryo death versus non-fertilization? Or does a bad egg sat on for 30 days look the same no matter what the cause? Thank you for any help.