At some point in the lineup, there must be a detour. At that point the lineup breaks down, because mind does not touch matter above the table. If you want to lift your little finger (point A), a physiologist can trace the neurotransmitter (B) that activates an impulse that runs down the axon of the nerve (C), causing a muscle cell to respond (D), resulting in the lifting of your little finger (E). However, nothing a physiologist can describe will get him from A to B – it requires a detour.(p. 100)
The best way to illustrate the folly of the reasoning behind the U-shaped diagrams is perhaps to go back to the sneeze and the molten lava example and see how the same logic turns my sneeze into the cause of an earthquake in Mexico City and the collapse of a building! I reproduce the quote above verbatim, but change the physiological events to geological ones. Here is how it goes:
The molecule and the molten lava are both above the line. A is a microscopic particle; all the other letters are physical processes that follow from A. … If you sneeze (A), then the other letters stand for the motion of the lava, the arrival of the seismic wave under the city, the displacement of the earth crust there, the collapse of a building, and so on. These are B, C, D, et cetera. All the physical changes that take place in the macroscopic world can be connected in a logical chain of cause and effect, except for the space after A. This is the point where the transformation from a microscopic sneeze molecule to a macroscopic motion first occurs – and it must occur, or the rest of the events will not happen.
At some point in the lineup, there must be a detour. At that point the lineup breaks down, because a sneeze molecule does not touch the molten lava above the table. A seismologist can trace the disturbance of the molten lava (B) that activates a seismic wave that runs to the fault under the city (C), causing a displacement of the earth crust there (D), resulting in the collapse of the building (E). However, nothing a seismologist can describe will get him from my sneeze A to B – it requires a detour.
Chopra’s quantum U-turns
“The same change from straight-line causes to U-shaped detours occurred when quantum physics was born. Although everything in nature once appeared to happen above the table, according to classic Newtonian theory … a few things could not be explained without a detour. The most obvious was light. … Light can behave like A, a wave, or B, a particle [which are connected by a U-shaped arrow]. These two are totally unalike in Newtonian physics, since waves are nonmaterial and particles are concrete. But light somehow can act like one or the other, depending on circumstances, and therefore it must have taken a detour under the line.