When the characters fly through the air, the space becomes an actual medium, not a dead zone.

NEWYORKER: Up

Leaving spectacles on a sink or vanity, where hair spray and perfume can fly through the air, adds to the residue.

WSJ: How to Clean Your Glasses Properly

Balls fly faster through thinner air and Madrid is 650 meters above sea level.

CNN: May 11, 2012 -- Updated 2124 GMT (0524 HKT)

After "eruptive activity" last year at the Cleveland volcano, University of Alaska Fairbanks scientist Steve McNutt noted that 90% of air freight from Asia to Europe and North America flies over Alaska airspace, and hundreds of flights fly through Anchorage's air space daily.

CNN: 2 Alaska volcanoes on alert as lava flows

It actually flew through the air and rumbled over roads, but didn't fly as well as the average plane nor drive as well as the average car.

FORBES: They Almost Changed the World

Past incidents of aircraft trying to fly through volcanic ash clouds and suffering damage and engine failure led European officials to shut their air spaces rather than risk a catastrophe, said Joe Sultana, an official at Eurocontrol, the intergovernmental body that manages European air travel.

CNN: Air travel paralyzed as volcanic ash cloud lingers