The headline is broadly defensible, but the qualifications matter. Effect sizes vary by population, the strongest claims rest on shorter trials, and credible voices push back on how it's typically framed.
the moment that you will tell me I am ready to go to bed and I am sleepy is the moment when you are on the greatest decelerating trajectory of your core body temperature it is high highly predictive of how sleepy you will feel
Every Sunday: the week’s new conflicts and verdict changes — and nothing else.
Native comments, Twitter mentions, and Reddit threads about this claim — surfaced together so the conversation isn't fragmented across platforms.
Bookmarking — the dossier-vs-overview split is the right call. Most of the time I want overview; sometimes I want receipts.
Would love a "what would change this verdict" RSS feed. Sign me up if it exists.
the moment that you feel most sleepy just let me know it turns out that before that we' done the um delightful um intervention of inserting a rectal probe into you because that's the best way that we can measure your core body temperature so we're measuring your core body temperature and sure enough despite you knowing nothing about what time it is the moment that you will tell me I am ready to go to bed and I am sleepy is the moment when you are on the greatest decelerating trajectory of your core body temperature
10 minutes of bright outdoor light within the first hour of waking anchors the circadian phase and improves sleep onset that night.
Morning sunlight exposure shifts the cortisol awakening response forward, improving daytime alertness.
Long-term morning sunlight reduces age-related macular degeneration risk.
Sleep regularity predicts all-cause mortality more strongly than sleep duration.
Tracking deep sleep on a wearable accurately reflects EEG-measured slow-wave sleep.
Caffeine has a half-life long enough that consumption after 2pm measurably degrades deep sleep in slow metabolizers.