Recall Ernst Mach's remark that the perception of sensation is connected to "dispositions of mind, feelings, and volitions". Some sensations are just more compelling than others. So even when perceptions have the same sensory magnitude they may still be distinguished by their vividness or affect. Maybe a feeling is attractive or scary; perhaps pleasant, or possibly painful. Anyway let us call this quality the sensory urgency and try to clarify it by reflecting on the following thought experiment. First select some sensation and call it the thermometric reference sensation. Represent it using a positive number noted as kT . Compare this thermometric reference sensation with the Anaxagorean sensation associated with seed Z. Determine the numbers a and b such that perceiving a copies of the thermometric reference sensation produces the same sensory urgency as b copies of Z. Report the result as
$\begin{align} \hat{K} \left( \sf{Z} \right) \equiv \frac { \it{a} } { \it{b} } \it k_{T} \end{align}$
The number $\hat{K}$ is called the vis viva of the seed Z. It is always greater than zero because a, b and kT are all positive numbers. Thus the notion of vis viva is quantified as a ratio of sensations.So to understand physics we must consider more than just physics. And that is why WikiMechanics is illustrated with quantized ethnographic art. Moreover definite numerical values are not assigned to $\hat{K}$. Instead, over the next few pages we use the results of calibrated laboratory experiments to develop the idea of vis viva into an account of temperature.
Here is a link to the most recent version of this content, including the full text.
Urgency |
Summary |
Adjective | Definition | |
Vis Viva | $\begin{align} \hat{K} \left( \sf{Z} \right) \equiv \frac { \it{a} } { \it{b} } \it k_{T} \end{align}$ | 4-5 |