They say that “prayers rise up like incense”…

The only problem with this is that the way smoke rises is governed by the heat equation

Otherwise known as the diffusion equation

It is like ink in water – it spreads randomly in all directions

And a coherent self-contained drop loses its identity and gradually disappears

And is gone…

 

The wave equation is what you want

To the casual eye it may look very similar to the heat equation, but no…

The wave equation - mirabile dictu! – reproduces its input, exactly, with a lag

 

That is why when I speak, you hear what I say.

The vibrations of air

That are set in motion by my voice

Are transmitted through the air, and are reproduced at your ear…

 

Were my speech to be governed by the diffusion equation

You would hear random noise.

My words would travel in all directions

Drifting apart, separating, and gradually disappear

Like an ink drop in a glass of water…

Or a cloud slowly drifting apart in the sky…