Thursday, January 28, 2016
Tanh, decumulate, accumulate
Professor Polistra is showing a tanh curve as always. But atypically it's a tanh inverted on x.
Represents a common phenomenon that deserves better understanding.
Current example is the gradual melting of snow on streets and roofs. Over the last few weeks, Spokane has been on the happy side of El Nino, with temps slightly above freezing (35/29) and frequent rain and fog. We started this period with heavy snow everywhere. About 10 inches on untouched cold spots, maybe 6 inches on most roofs. For the first 2/3 of this period of steady slight warmth, snow height remained nearly constant. Suddenly everything melted to near zero, then the few remaining deep patches melted.
What happened at the sudden drop? Clearly there's a critical threshold where the few open patches have enough "influence" to "infiltrate" the average areas. But I don't know what "influence" and "infiltrate" mean in specific thermodynamic terms. Are the few open patches picking up sunlight? Gathering rain which spreads and undercuts the average areas?
Clearly a large area with NO melted patches is much harder to melt.
A similar process happens in the other direction with leaf accumulation on a roof, or leaves forming dams in a street gutter or creek. When leaf input is insufficient to form "islands", wind and water can carry away all the leaves. When input exceeds carryoff even briefly, the resultant "islands" are able to trap more leaves, resulting finally in complete coverage or complete damming.
Boiling water follows the same pattern, though the notion of accumulation doesn't work the same way.
Spreading of an idea, or mob action. Steady heat of idiocy causes nothing, until a few islands of venting vapor start to accumulate more bubbles.
Professor Polistra is showing a tanh curve as always. But atypically it's a tanh inverted on x.
Represents a common phenomenon that deserves better understanding.
Current example is the gradual melting of snow on streets and roofs. Over the last few weeks, Spokane has been on the happy side of El Nino, with temps slightly above freezing (35/29) and frequent rain and fog. We started this period with heavy snow everywhere. About 10 inches on untouched cold spots, maybe 6 inches on most roofs. For the first 2/3 of this period of steady slight warmth, snow height remained nearly constant. Suddenly everything melted to near zero, then the few remaining deep patches melted.
What happened at the sudden drop? Clearly there's a critical threshold where the few open patches have enough "influence" to "infiltrate" the average areas. But I don't know what "influence" and "infiltrate" mean in specific thermodynamic terms. Are the few open patches picking up sunlight? Gathering rain which spreads and undercuts the average areas?
Clearly a large area with NO melted patches is much harder to melt.
A similar process happens in the other direction with leaf accumulation on a roof, or leaves forming dams in a street gutter or creek. When leaf input is insufficient to form "islands", wind and water can carry away all the leaves. When input exceeds carryoff even briefly, the resultant "islands" are able to trap more leaves, resulting finally in complete coverage or complete damming.
Boiling water follows the same pattern, though the notion of accumulation doesn't work the same way.
Spreading of an idea, or mob action. Steady heat of idiocy causes nothing, until a few islands of venting vapor start to accumulate more bubbles.Labels: Grand Blueprint, Heimatkunde
¶ 4:41 AM
