I am neither physicist nor engineer (probably shoulda been the latter, and still kick myself periodically), but I today observed that the two biggest problems with the typical Osterizer-type kitchen blender are:
1. Surface tension (or maybe it should be viscosity?): to wit, the stuff wants to stick to the sides of the jar rather than going meekly to its fate 'midst the blades; and
2. Speaking of said blades...cavitation. When the stuff at the surface stops moving and the motor is howling, you know your blades are slicing mostly air. Shut it down and burp it.
I have a sort of hazy mental image of a triple-bladed blender setup, in which the center set of blades would rotate much more slowly, to break up (okay, maybe) the cavitation bubbles as they form while the upper and lower sets make with the chopping, pureeing, or what have you. I can only imagine how complex the gearing would have to be, and what such a blender would cost to make.
In other news, if that gazpacho recipe had been any bigger Elder Son and I wouldn't have anything to put it in.