12/20/2025
I'm resharing Daylight Computer's newsletter on the Winter Soltice because it is vital to get your light AND temperture correct.
Daylight is still having their winter bundle sale for their bluelight & flicker free computer HERE (http://www.improvementwarriorfitness.com/daylight). Use code improvementwarrior
Yesterday I overdid it on the cold exposure. Just like sun exposure and exercise and food.......your body will tell you when it's had enough.
Afternoon my resolve for the cold is usually a lot less than in the AM. But after my shirtless walk to pick up my son at the bus stop, it took me about an hour to recover fully. Normally it's just minutes.
I just couldn't get warm. Even had to put another sweatshirt on.
But first day back from vacation was in the 40's, then Thursday was in the 50's, and then yesterday in the low 20's all day.
So I overdid it.
But today am back strong and mitcohdria is humming along as my internal heaters are working strong again.
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Anyway here is Daylight's newsletter: With a couple of my memes thrown in ;)
Winter Soltice and the Return of the Light
On Saturday, December 21st at 1:21 AM PST, we'll experience the December solstice—the shortest day and longest night of the year in the Northern Hemisphere.
The December solstice is not a calendar day, but a moment in time. It occurs when Earth's North Pole reaches its maximum tilt away from the sun—a full 23.5 degrees. At this moment, the Northern Hemisphere receives the least amount of direct sunlight it will get all year. Meanwhile, our friends in the Southern Hemisphere are experiencing their summer solstice, enjoying their longest day.
NASA graphic showing the orientation of Earth's tilt relative to the sun during the summer and winter solstices. (Image credit: NASA/Genna Duberstein)
This astronomical event has profound effects on how we live. With less than 8 hours of daylight in many northern cities, we're spending significantly more time indoors, under artificial lights, in front of screens.
Our Ancestors Took Light Seriously
Five thousand years ago, ancient people in Ireland built something remarkable: Newgrange, a massive passage tomb specifically designed to capture the winter solstice sunrise. On this one day each year, for exactly 17 minutes, sunlight penetrates through a carefully crafted opening above the entrance and illuminates the inner chamber in a golden glow.
Newgrange, Ireland. Image credit: Ireland OPW
In an era without modern tools, people moved massive stones and performed precise astronomical calculations—all to mark this single moment when the light begins its return.
They understood something we're only now remembering: our relationship with light isn't trivial. It's fundamental to our biology, our rhythms, our wellbeing.
Pro tip: Every year, Ireland livestreams the December solstice event from the ancient passage tomb at Newgrange. This year, you can watch the broadcast live on Sunday, 21 December, from 8:40a.m. Irish time on their Office of Public Works Youtube channel.
Today's Light Problem
With colder temperatures and less than 8 hours of daylight in many northern cities, we're spending significantly more time indoors. But unlike our ancestors who carefully tracked and honored natural light, we're flooding ourselves with artificial blue light from screens and indoor lighting, precisely when our bodies are getting the least natural light.
If you're going to spend more time indoors this winter, you might as well make your workspace as cozy and health-supporting as a warm fireplace. That's where Daylight comes in. Computing that feels like curling up with a good book instead of staring into a slot machine.
After the solstice, each day will gradually bring more light—but until spring returns, let's make our indoor time as nourishing as possible.
Our ancestors built monuments to celebrate this return. We're building technology that honors it.
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Enjoy your weekend! Now get outside, ground your feet and become harder to kill
Thoughts/questions/comments
Stay strong, stay positive, be the Improvement Warrior!
Coach Yun
