simple heated filament is still the right tool. My old 2023 Chevy Spark had incandescent tail
lights. | understood why.

The therapeutic quality of incandescent light at low intensity is something worth investigating
seriously. CozZie Glow may be the first system to document the PWM colour shift from full white
through ember to ghost mode in a controlled, repeatable way. | have not studied the full
physiological effects of moving through these colour temperatures. But | have lived them.

| started writing this section with a migraine. | took a sumatriptan, dialled CozZie Glow down to a
low warm output, and lay in the tent. An hour later | felt okay. That is one data point. It is mine. It
is documented here.

The metrics worth studying: melatonin onset timing under incandescent low PWM versus LED
warm white. Cortisol suppression at different colour temperatures. Migraine frequency and
severity correlated with evening light exposure. Biphasic sleep patterns under natural colour
temperature cycling — humans historically slept in two phases before artificial light disrupted the
pattern. Autonomic nervous system response measured via heart rate variability. CozZie Glow
already logs Garmin HRV data. The infrastructure for this research exists.

Nobody has studied ghost mode. The Canon RAW histogram data collected during this project
may be the only documentation of its spectral properties that exists anywhere.

The PWM Colour Temperature Effect

As voltage to an incandescent bulb decreases, the filament cools. A cooler filament glows less
brightly — but it also shifts colour. The spectrum moves. At full brightness the filament runs hot
— white light, full spectrum. As PWM reduces and the filament cools, the output shifts
progressively:

Full brightness — warm white — yellow — orange — red — deep red —> near infrared —
infrared

This is black body radiation. The colour of light emitted by a heated object is directly determined
by its temperature. The sun at noon is white. The sun at sunset is deep red. A dying campfire is
infrared warmth you feel before you see.

Ember Mode

At low PWM levels the filament reaches what | call Ember Mode. The colour temperature
matches a glowing coal — deep orange-red, warm, primal. The same light humans have fallen
asleep beside for the entirety of our existence on this planet. Soft. Non-stimulating. The nervous
system recognises it.