Words: 77 (16×15 grid)
Average Length: 5.14
Difficulty: 2-4 out of 5
The difficulty range depends on whether certain mathematical/physical symbols are all Greek to you. Helpful hints/spoilers for the theme answers are below the photo. I hope you enjoy the puzzle. Next week (11/14) brings a challenging Themeless.

HINTS/SPOILERS:
19A: Psi is the symbol for the wave function.
26A: Lambda is the symbol for wavelength
57A: Rho is the symbol for density
60A: Nu is the symbol for degrees of freedom