To help explain the bioluminescent process vs fluorescent more clearly I asked for some help from my science advisor on this project, Dr Siouxsie Wiles. Here is her brilliant explanation:
Bioluminescence is a chemical reaction that produces light. Fluorescence is very different - its when light is emitted by a protein. Basically the protein gets 'excited' by light of a particular wavelength. Electrons move out of their orbits, and when they return, they cause the protein to emit light of a different wavelength. Jellyfish have probably the most famous example of a fluorescent protein - green fluorescent protein or GFP. This is a protein that emits green light when excited with blue light. Jellyfish also produce a luciferase/luciferin system which most likely produces the light that excites GFP to produce its green light.
bioluminescence = a chemical reaction (no 'excitation' required)
fluorescence = light produced by a protein when 'excited' by light of the correct wavelength
A fundamental difference between the two is that bioluminescence requires the organism to be alive, as it requires energy - ATP or FMNH2. Dead things can still fluoresce as fluorescence doesn't require energy, just the fluorescent protein, so a dead creature can fluoresce until the fluorescent protein has naturally degraded. This makes a huge difference to my work - we use bioluminescence to measure in real time whether our bacteria are dead or alive, where as we use fluorescent proteins for microscopy to find out where our bacteria are on tissue samples that have been fixed with nasty chemicals, which kill the bacteria.
Thank you Dr Wiles! That does help explain it!
Did I mention this painting glows in the dark? It does! For added light play I painted just the Jellyfish with some fun glow in the dark paint. I'll do another post with a gif that shows the painting in the light and then in the dark.
I mentioned earlier that my goal is to paint two paintings on bioluminescence this month and I'm off to start the next one. However, it looks like I may not finish the next one until next month, since I plan this following painting to be a large landscape with the ocean and organic materials in the foreground. It's going to be a lot of work. But I will at the very least post a few updates this month if I can't complete it until next month.
Thank you so much for being my patron. More on the science of bioluminescence soon!
PS: Did you know that Crystal jellyfish are cannibals and that they are hard to raise together in captivity because they have a fondness for eating each other? True! And they can open their "mouth" and swallow things at least half as big as they are. Beautiful and hungry little sea monsters that live right outside my door in the oceans off the coast of California!