Abstract :
On the occasion of Ed Larsen’s 60th birthday I am pleased and honored to discuss some of the many important contributions he has made to transport theory and to the practical business of particle transport calculations. I must begin with two caveats. First, Ed’s contributions cover more territory than I can competently discuss. This paper therefore neglects some of his contributions, only briefly refers to others, and describes in some detail the contributions that I have understood to be especially profound and significant. Second, at age 60 Ed shows no signs of slowing down; thus, his work to date is only a subset of the contributions he is likely to provide by the end of his remarkable career.