Page 154 - The Cambrian Evidence that Darwin Failed to Comprehend

The Cambrian Evidence That Darwin Failed to Comprehend

refractive index of calcite is 1.6, and that of the chitin beneath it is
1.53.
Huygens and Descartes’ lens designs provide an ideal eye
structure, and the trilobite’s eye is highly compatible with those de-
signs. However, Huygens and Descartes’ designs were based on the
existence of just one unit. But one unit is not enough for the trilobite
eye, because the refractive index of the water in which trilobites
lived is different from that of the air.
This is where the usefulness of the bottom lens unit comes in.
The deviation that occurs in a water environment is overcome by
this second unit—which only goes to demonstrate the complexity in
the structure in question.
Levi-Setti stated the following about this property of the trilo-
bite lens:

There is in fact only one choice of indices for which the lens brings an
incident parallel beam to a focus. This involves the upper lens being
made of calcite (n=1.66) and the intralensar bowl being made of chit-
in (n=1.53). 116
In addition, the mathematical solution in the trilobite lens is
based upon several laws and principles. Levi-Setti says:

Trilobites had solved a very elegant physical problem and apparently
knew about Fermat’s principle, Abbé’s sine
law, Snell’s laws of refraction and the
optics of birefringent crystals. 117

It would, of course, be ir-
rational to claim that a prehis-
toric animal could possess
any knowledge of the laws of
optics as set out by Levi-Setti. It is
impossible for a trilobite to have

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