clifford_a-_pickover_surfing_through_hyperspacebookfi-org

202 appendix h
Figure H.4 Projection of a 4-D 120-cell regular polytope. (Courtesy of Professor
Carlo H. Sequin.)
The Ultimate Challenge of Living in Other Dimensions
Physicists cannot give a reason why space has three dimensions. Perhaps the
dimensionality of space in our universe was "accidentally" determined during the
Big Bang, billions of years ago. It does seem that life would be more challenging in
other dimensions. As we discussed, it would be difficult for digestive tracts to run
through a creature in two dimensions because the tract would cut the creature into
two pieces. Richard Morris in Cosmic Questions suggests that if the dimensionality
of space were four or greater, then stable planetary orbits would not be possible.
Morris implies that if a planet did manage to form, it would follow a path that
caused it to spiral into the sun. This line of thinking is extended in Max Tegmark's
wonderful recent article "On the Dimensionality of Spacetime" appearing in the
journal Classical and Quantum Gravity (see Further Readings).