When you stir a tea or coffee cup, the spoon makes a noise that increases in pitch the longer you stir. If you stir indefinitely, will the noise keep getting higher, or will it reach a peak pitch? Will something else happen?
You can check the answer of the people under the question at Quora “coffee cup that stirs itself“
I noted the same phenomena this morning in a mug of coffee with powdered creamer and sugar having just previously been stirred into the coffee. I did one test after about sixty seconds with the coffee had come to a stop from swirling from the stirring. No longer was there a noticeable change in pitch as heard before.
Here are my hypotheses:
The rapid cooling of the coffee/tea from the very high heat either causes or is involved with the phenomena.
I am guessing there is a steep reverse exponential slope to the cooling that is, the very hot liquid cools much faster when its temperature is very different from the room than later when only mildly hot. Thus the “rapid” (hypothetical) early cooling causes the pitch change.
The molecular level changes as the sugar and creamer molecules combine with the water steadily change the average density of the liquid causing the vibration characteristics of the material (the liquid) to change.
Thus, once the sugar and creamer molecules are evenly distributed (from stirring, heat and ordinary diffusion) the rise in pitch stops.
There could be some other explanation, but, a superficial answer is that in every day life one can usually observe that few phenomena continue infinitely along some particular geometric curve. Your interesting question is an observation that one can plot on a graph (some line or curve). While interesting and useful to consider such a “curve”, one cannot assume that the curve continues infinitely in either direction “in real life”.
Scientifically, one must keep in mind that the math is only a “model” of the phenomena. The phenomena is what it is no matter what the (current) math says. This sort of caution allows for discovering/understanding deeper phenomena as math and observation improve.
I may conduct a few experiments for fun and let you know my findings!
I really don’t know what you’re talking about, so I’m not sure how to answer this other than “No, it doesn’t.”
Perhaps you’re hitting the sides of the cup harder and harder the longer you stir, or changing your rate of stirring? But no, spoons do not make any sort of rising pitch the longer you stir a hot beverage with them.