C as desert island programming language but making all indexing 1-based: "the first element of any integer-indexed object is found at index 1, not index 0, and the last element is found at index n rather than n-1, when the string has a length of n." Also begin end blocks - maybe there was a pascal ninja hidden in the syntax committee room?

Matlab, Octave, Mathematica, and other mathematical programming environments use 1-based indexing, it's a well-established norm for the domain.

Fortran too and in HPC we all code in Fortran a lot. Look at the loop construct:

     for i = 1:t

in Fortran:

     DO I=1,T

The ability to load both C and Fortran dynamic libraries is also really really nice.

Does 1-based indexing have any advantage, beyond familiarity to scientists?

Dijkstra to the rescue: http://www.cs.utexas.edu/users/EWD/transcriptions/EWD08xx/EW...

With 1-based indexing, length == last index.

Does 0-based indexing have any advantage, beyond ability to do pointer arithmetic with indexes?

In 0-based indexing, n % length is a value inside the range.

Not really, but it's not important either way.

More likely Matlab than Pascal.

  Julia's syntax is intended to be familiar to users of MATLAB®.