1. Ancient Roman camps were built with beds aligned north–south. Commanders believed men woke sharper and calmer. Centuries later, NASA used similar orientation tests in isolation chambers—and found the same effect: lower heart rate, faster REM entry, and deeper recovery. ⸻ 2. The reason lies in Earth’s magnetic field. Our nervous system runs on tiny electrical currents. When the body aligns north–south, the heart’s electromagnetic vector runs parallel to the planet’s field—minimizing interference and micro-stress. ⸻ 3. In sleep labs, participants who slept east–west showed up to 20% more nighttime micro-arousals—brief stress awakenings the brain doesn’t remember but that fragment rest. Facing north reduced them by half. ⸻ 4. Astronauts on the ISS were later positioned relative to Earth’s magnetic axis for the same reason: Synchronizing circadian rhythms through spatial orientation. The body rests deeper when internal and external polarity agree. ⸻ 5. The Roman commander’s order now reads like wisdom: “Rest as the world itself rests.” Try it tonight—head north, minimal electronics, slow breathing. You’ll feel the difference within days. Sometimes what we call ancient superstition was just unmeasured physics.