For example, my thought process on the whole thing was 1/4 wavelength spacing simplifies the phased array calculations, what is 1/4 wavelength at 40KHz, and the answer is, of course, it depends ...

Ben Bartlett created an array of hexagonal mirrors that can reflect the sun's rays in any pattern and can be created by 3D printing. This 3D-printable hexagonal mirror array was created to apply ...