Friday, January 21, 2011

Tiny catastrophes

little catastrophes

Dew condenses on a curved glass surface.
Some time later a random drop becomes too heavy and slides down the curved surface.
As it descends it absorbs other dewdrops and grows heavier.
Once a dewdrop starts falling it's downfall is irreversible.
How much of our lives is governed by processes that behave in the same manner?
In a chain reaction, positive feedback leads to a self-amplifying chain of events.
Cascading failure is ... when one of the elements fails (completely or partially) and shifts its load to nearby elements in the system. Those nearby elements are then pushed beyond their capacity so they become overloaded and shift their load onto other elements.
A catastrophic failure is a sudden and total failure of some system from which recovery is impossible. Catastrophic failures often lead to cascading systems failure.
Bifurcation theory studies and classifies phenomena characterized by sudden shifts in behavior arising from small changes in circumstances. This may lead to sudden and dramatic changes, for example the unpredictable timing and magnitude of a landslide.
Marcel Minnaert does not mention cascading processes in his observation guidebooks. But as an astrophysicist he should have known about positive feedback and singularities. I will have to check if "black holes" were known in his time.

No comments:

Post a Comment