You probably know something about the way the atmosphere behaves without even realizing it. Picture the familiar tableau: a proud, silvery jetliner sails into shadowy clouds at 20,000 feet. Blocks of ice clang ominously against highball glasses in first class. A calm-sounding pilot makes an announcement about seat trays when the plane suddenly jerks and plummets. As flight attendants scramble and carry-on luggage tumbles from the overhead bins, the power flickers out. Sinister yellow oxygen masks backlit by emergency signs dangle over the frightened passengers.

Now think about the last time you boiled a pot of water to make pasta and began to read the microscopic instructions. Unless you’re a Denver transplant or you drive home to Mount Mitchell over breaks, you probably skipped over the part about high altitude cooking.

Did you ever stop and think why the passengers need the oxygen masks? Why noodles take longer to cook in the mountains? The answer is actually the same. These are some interesting examples of how air changes with height. Air is a fluid, so its density is affected by gravitational pull, temperature, and pressure. Here at the surface, we experience the full weight of the air above us. The higher up you go, there’s less pushing down from above, so the air is less dense (and colder). At 3,000 feet, there are fewer air molecules to bounce around than at sea level, so air can heat more quickly. According to the USDA, a pot of water in Boone will boil at 206 degrees Fahrenheit instead of the usual 212. This temperature is lower, so the food must cook for a slightly longer period of time in Boone than it would at sealevel.

In the case of the jetliner, the altitude is 20,000 feet or more. Though the cabin is pressurized under normal circumstances, stress or turbulence may cause the structure of the plane to come apart and the air to rush outwards. Of course, the air is much thinner at those altitudes, so humans wouldn’t receive enough oxygen when breathing. The oxygen supplied by the masks enables the passengers and pilots to continue flying without blacking out.