Check out the Scale of the Universe to see examples from the huge to the tiny, from subatomic particles up to the galaxies, and many things in between. Human sizes seem to be about in the middle, between 10-35 and 1035. Watch “Cosmos” (a remake) by Neil deGrasse for details on the formation of the universe.
Satellites can calculate groundwater disappearance by measuring a decrease in gravitational attraction. With less water in the ground, there is less mass and less attraction. The Colorado River Basin has lost 17 trillion gallons since 2004, mostly groundwater. Our water use is steadily growing, but groundwater losses take millennia to be restored by nature. Seventy percent of the basin’s water […]