as someone marooned on the romantic side of the Cartesian rift, I've just read the middle page of this thread and was horrified. Needless to say I didn't get the joke...

...I use fingers for most of my calculations, and limit my calculations to those that can be done on fingers...

That would be a digital calculation?

To pass the time, in my head I calculate the gravitional perturbations of my backpack on my cranium, and the perturbations of my cranium on my backpack. (I am a perturbed little man.) I assume a centrally symmetrical, static gravitional field, degenerating at infinity. When gravitional potentials are applied, from them the energy tensor of the matter in my cranium can be calculated on the basis of the field equations of gravitation.

Robert,

I think you need to get out more. Perhaps you could try hiking with other folks.

I'm not allowed to actually hike: they roll me along like they did Anthony Hopkins in "Silence of the Lambs."