Dendrochronology holds a special place in my heart, because it's the thing that finally shook me out of my young earth creationist (YEC) haze about 9 years ago.

Dendrochronology holds a special place in my heart, because it's the thing that finally shook me out of my young earth creationist (YEC) haze about 9 years ago. As the Wikipedia page states, we have a good chronology going back about 12k years, which is a few thousand years before all YEC timelines. Other more complicated dating techniques like radiocarbon dating and ice cores are too abstract or complicated, and therefore easier to hand wave away as containing too many unprovable assumptions. For instance, serious YEC people like to point out that we're assuming that the speed of light or radioactive decay rates were constant in the recent past. If it seems insane to cling to bad arguments like this, welcome to the world of science-minded YEC people. But tree rings... everyone has seen tree rings, and everyone knows that sometimes they're thicker and sometimes thinner. That's hard to argue away. The YEC camp tries: they point out we're assuming there's one ring per year. But when I realized that this really was their best argument, I had to give up YEC and find out how deep the rabbit hole went. About a year later, I was an atheist.