One day, in a forest in southern Minnesota, a great tree will fall down. This tree might become covered in lichen, moss, and fungus as it slowly decays. It may become a home for small animals or a damp, dark, warm place for invertebrates. Perhaps the tree may be split up for firewood.
Eventually, someday, this tree will no longer be standing.
And when it comes down, someone might be poking through the remains. Whether the tree rots or whether it is split up, some being will inevitably find a strange piece of metal there. This piece of metal, long ago absorbed into the tree and healed over, will be a lasting testament to practices of a previous era.
And this little piece of metal will be my fault.
The tree in question is a maple tree, and the cold nights and warm days mean that sap is running here in Minnesota. Somehow, today, one of my students managed to break off the tip of a drill bit inside the tree. It was freezing today, which may have made the metal more brittle; the cold weather certainly made tree tapping less fun, since the sap will only run out once the weather warms up.
In any case, there is now a lasting testament to my work here. By next year, no one will be able to see this inch of metal bit. But years in the future, someone or some thing will find this bit and know just a little more about the past.