It's my body cracking like a glow stick whenever I move yet refusing to glow and the subsequent disappointment felt.
Every time I wake up and all my joints crack, yet I don't receive an invigorating glow to help rouse me for the morning, is a disappointment.
Crack? Crack is easy. What really blows is sand, in your joints. That kind of role will get your hot box orbs glowing
Technically you ARE glowing. The bioluminescence is just very dim. I hope this helps!
And you're also hot. (You emit IR light)