Almrond

It may be inherently flawed, but we can’t just arbitrarily emit wavelengths of light with current technology. Realistically I doubt we ever could, we would need to alter the emission energies of materials on the fly, which would be akin to actual magic. It is frankly amazing it works as well as it does notwithstanding.

The ancient Romans made it a point to not buy slaves from the asbestos mines due to their poor health, it has been known for far too long that asbestos is harmful. It also happens to be insanely useful.