Geography
Why Do Time-Zone Borders Zigzag?
Dividing Earth into 24 gives an average width of 15 degrees, but standard time is a social system. Governments bend boundaries to keep cities, regions, commuters and trade networks together.
GEOGRAPHY
Geography
Scale, distance, and the ways places shape the lives lived within them.Geography
Why Does Greenland Look Huge on World Maps?
Mercator stretches both east-west and north-south scale at high latitudes to preserve angles and local shape. The tradeoff greatly exaggerates polar area.
Geography
Why Do Deserts Get Cold at Night?
Clear dry desert air has little cloud or water vapor to return outgoing infrared energy. Ground that heats quickly by day can therefore lose heat quickly after sunset.
Geography
Why Do Rivers Meander?
Faster water erodes the outside of a bend while slower water deposits sediment inside. This contrast amplifies small curves and moves the channel sideways.
Geography
Why Is the Ocean Salty?
Rain and rivers carry ions weathered from rocks to the sea, while seafloor reactions add others. Evaporation removes water but leaves dissolved salts behind.
Geography
A Mountain Shorter Than Everest Is Closer to Space
Because Earth bulges at the equator, Ecuador's Chimborazo is farther from Earth's center than Mount Everest.
