QED vs ATM

[lifedata@vol.com]

After someone recommended it, I bought and am reading the Faynman
(sp) book, "QED."

Has anybody found this stuff to be of actual use regarding mirrors,
wave fronts, diffraction rings, etc?  He claims QED is the perfect
answer to everything from motorcycle tires to roofing nails to tomato
soup (almost, sort of), but at every point the adjective "roughly"
modifies the results and attempting to get accurate results destroys
them completely.

It statedly offers no "how" or "why," just approximated expectations. 
I can see how QED might be a good tool to give people research ideas,
but I'm having trouble seeing the practical value of it.

Jim L
1 John 5:13