The "ratio of yellow photons to blue photons" is a verbatim quote from the podcast episode. Huberman didn't expand on that in the episode, and (again) my search for specifics yielded no additional understanding.
But Huberman was quite clear that the spectrum of light when the sun is low in the sky is different somehow from the spectrum when it is high, and the eye has some way to detect this difference.
The important fact is that when the sun is high in the sky, the light has very little effect on the timing of a person's circadian rhythm, and Huberman was quite clear on that too.
But Huberman was quite clear that the spectrum of light when the sun is low in the sky is different somehow from the spectrum when it is high, and the eye has some way to detect this difference.
The important fact is that when the sun is high in the sky, the light has very little effect on the timing of a person's circadian rhythm, and Huberman was quite clear on that too.
Most people do not seem to know that yet!