Some fuses are quick, some are slow. When I say fuses, I am referring to the electrical type, not the wick on dynamite, all though the same can apply. Whether slow or quick, either type of fuse would be considered comparatively fast to our human point of time reference. From a geological time perspective, a human lifetime is an imperceptible blip, a nano of a nanosecond. Or even much less.
As with nearly all things subjective, slow or fast all depends on ones perspective.
I came to ponder the perception of time after discovering this brick chimney in what looks to be a state of slow explosion. Often the issues found during a home inspection have taken years, perhaps even decades to get where they are at that particular moment in time. This chimney is no exception.
The bricks are literally slowly blowing apart. This condition is known as spalling. What is occurring may best be described as flaking. The bricks are slowly, relatively speaking, falling apart in layers.
What causes spalling is thought to be inferior bricks, not properly fired or reclaimed brick. The brick is too porous, thus able to retain a greater amount of moisture. Through the freeze thaw cycle, the surface areas begin to crack and fall away.
This chimney is one of the most extreme case I have even happened upon. Amazingly the mortar joints are still intact, while the brick has long crumbled away. Unfortunately repair will be almost assuredly be large. Quite possibly the entire chimney or at the very least a good portion of it, will need to be rebuilt.
Spalling is progressive, it heeds no clock nor calendar. It will continue unabated until time has completed the process.