Here we find out if molten glass is transparent. If the video is too technical or boring, skip to 4:30 minutes in, and have fun watching 50mW lasers hit molten glass!
NOTE: I realized after posting that transmittance is reduced by 2 effects, some from reflecting off the surface of the glass, and some from dissipation in the glass. That means light travelling through the glass probably dissipates at a rate significantly less than 10% per centimetre. A technical, but useful discussion can be found here:
The channels of the two people who tried to answer the challenge are:
Thanks again for the input.
The Sixty Symbols Glass Video: