Recently I cut a 3 cm width piece of pine, see picture (Steve Good's pattern). After a few days, the piece of wood started to crack and there were fissures all around. I knew this might happen because the wood was really fresh green, but I just wanted to give it a try. After two weeks, all the cracks simply disappeared, as if the wood shrinked to its original shape. Unfortunately I don't have a picture with the cracks.
Since I am a total newbie, I just wanted to ask if this is kind of normal and if you know the reason why this happened.
Thanks!