Circle of latitude 45 degrees north of Earth's equator. Crosses Europe, Asia, Pacific, North America, and Atlantic Oceans. True halfway point is 16.038487 km north due to Earth's oblate shape
Argyria is caused by excessive silver exposure leading to blue skin discoloration. Can manifest as generalized or localized argyria affecting body surfaces. Term comes from Ancient Greek 'argyros' meaning silver
Sunlight consists of infrared, visible, and ultraviolet light. Global average sunlight reaches Earth at 164-340 watts per square meter. Sunlight takes 8.3 minutes to reach Earth from Sun's surface. Sunlight spectrum spans 100 nm to 1 mm wavelength range
The equator divides Earth into Northern and Southern Hemispheres at 0° latitude. It spans 40,075 kilometers and is located halfway between poles. The equator passes through 13 countries, including 11 in direct contact
International peer-reviewed journal on daylighting in buildings. Started in 2014, publishes bi-annually with 70-day publication time. Open access with no publication fees
Daily dose for adults is 5000 IU based on average body weight. Children need 1000 IU daily, pregnant women 4000-6000 IU. Optimal level is 25(OH)D value of 60 ng/ml. Sun exposure can help maintain optimal levels