As altitude increases, the concentration remains the same but the number of oxygen molecules per breath is reduced. At 12,000 feet (3,658 meters) the barometric pressure is only 483 mmHg, so there are ...

As air becomes less dense, it contains less gases per unit of volume, and therefore less oxygen ... other than altitude also effect the density of air. For one thing, water molecules have less ...

During the winter months, Southern California-based NASA aerospace engineer Frank Tai and his wife get their mountain-town ...