I'm currently taking a math class in College called "Scientific Computing" and the professor told us that C is the most common language used for, well, scientific computing and am just wondering as to how accurate this professor is?
In my business (particle physics) we pretty much moved from Fortran 77 straight to c++ and python. Those of us who care about programming all know C, but it is only written for niche applications (embedded DAQ boards, special purpose drivers, ...).
That being said, higher-level linear-algebra libraries often delegate to BLAS and LAPACK for the heavy lifting (this includes Eigen and numpy). Though originally written as Fortran libraries, the versions shipped nowadays on many systems are implemented in C.
In any case, learning C will give you a firm foundation for programming, and it is rarely profitable to argue with professors.