M. Kwiecinski et L. Noirel, ON A QUESTION OF THOM,RENE CONCERNING PRO JECTIONS OF A WHITNEY STRATIFICATION, Comptes rendus de l'Academie des sciences. Serie 1, Mathematique, 318(2), 1994, pp. 149-152
Rene Thom asked whether the image of a Whitney-regular stratified set
in R(N+1) by almost all projections is Whitney-stratifiable. We give a
negative answer, considering a curve with isolated singularity. The e
xample we construct is a rapid spiral based on a ''ploughing of the sp
here''.