D&D 5E Shape Water, glowing water

[Stattick]

Would you allow the cantrip Shape Water to cause water to glow? Perhaps just a dim, 10' glow?

 

[aco175]

I have never had anyone take this spell. It seems kind of useless unless you want to leave a marker for others to follow you or something.

It says you can change the color or make it clear but does not mention making it glow. You can freeze it, so I might allow it to act as a prism and filter light but I would rule that it cannot glow on its own. Take light cantrip for that. I would be interested in seeing if others have cool ideas for it to make it worth taking.

 

[Stattick]

It's interesting that Cherenkov radiation & water that glows due to bioluminescent algae, both glow the same color of electric blue. I don't have the grounding in science to really understand, but I read somewhere that the blue glow is simply the color that water must glow, because of something having to do with the shape of water molecules absorbing the red and green spectrums, while being far less efficient at absorbing the blue.

 

[Dave Goff]

I wouldn't say so, RAW or RAI, and I would even have to be convinced to let it by way of "rule of cool".
I do wonder what the application of the glowing water would be. Can you share why someone wanted to make water glow?

I'll disagree with aco175 about it being useless. I mean, it's a cantrip, so it's not powerful, but I still think it can have some creative uses.
I wrote about the Shape Water cantrip here, if you're interested. (I don't mean for this to be spam, so fair warning up front- that link goes to my blog.)