I don't think lightening is the explanation. Those things were granite, not trees. There was no moisture in them to be super heated into steam. Was there a storm at that time and location?
There is water in granite, but only something less than 1%, enough though to fracture it with rapid heating. There is water in most things, even glass, although obviously much less. If it is at all porous it will contain some water, if only as a result of the air in the pores containing water vapour...
I don't think lightening is the explanation. Those things were granite, not trees. There was no moisture in them to be super heated into steam. Was there a storm at that time and location?
There is water in granite, but only something less than 1%, enough though to fracture it with rapid heating. There is water in most things, even glass, although obviously much less. If it is at all porous it will contain some water, if only as a result of the air in the pores containing water vapour...