The invention of the rubber eraser trailed the invention of the pencil by two centuries; the first wood-and-graphite pencils were created in the 16th century, but rubber erasers weren’t invented until the late 18th century.
Air guitarists rejoice; since 2003, the U.S. Air Guitar Championships have provided an outlet for aspiring air guitarists to rock out in front of a crowd and climb to the heights of air guitar fame.
Counterintuitively, people who live near coal-driven power plants have a higher level of radiation exposure than those living near nuclear-powered plants; coal ash contains uranium and the radioactive byproducts of coal combustion are more poorly controlled and regulated than the byproducts in the nuclear industry.
The 2012 Summer Olympics were the first Olympics where every participating country sent at least one female athlete.
Playing Iron Man proved to be quite lucrative for Robert Downey Jr.; for his role in Iron Man he was paid $500,000, when reprising it in the sequel he was paid $10,000,000, and when he appeared as Iron Man in The Avengers he was paid $50,000,000.
There are subtle differences between the different kinds of carbonated water: seltzer water is simply water with carbonation added, club soda is water, carbonation, and salt, and tonic water is water, carbonation, sugar, and quinine (a bitter plant extract originally included in tonic water to protect British troops against malaria, now used in lesser quantity for flavor).